Poganizira zovuta za chilengedwe ndi kusintha kwa mphamvu, electrochemical CO2 reduction (ECR) ku mafuta owonjezera a multicarbon (C2 +) ndi mankhwala, pogwiritsa ntchito magetsi ongowonjezedwanso, akupereka njira yabwino kwambiri yotsekera mpweya wa carbon ndi phindu lachuma.Komabe, kulumikizana kwa electrocatalytic C─C mu ma electrolyte amadzimadzi kumakhalabe vuto lotseguka chifukwa cha kusankha kochepa, zochita, komanso kukhazikika.Mapangidwe a zopangira ndi ma reactors ali ndi chinsinsi chothana ndi zovutazo.Timapereka chidule cha momwe tingakwaniritsire kulumikizana kwa C─C koyenera kudzera pa ECR, ndikugogomezera njira zama electrocatalysts ndi electrocatalytic electrode/reactor design, ndi njira zofananira.Kuphatikiza apo, zopinga zaposachedwa komanso mwayi wamtsogolo wa C2 + wopanga zinthu zimakambidwa.Tikufuna kupereka ndemanga yatsatanetsatane ya njira zamakono zolumikizira C─C kwa anthu ammudzi kuti apititse patsogolo chitukuko ndi chilimbikitso pakumvetsetsa kofunikira komanso kugwiritsa ntchito ukadaulo.

Kutulutsa mpweya wochuluka wa carbon dioxide (CO2) mumlengalenga kwadzetsa mavuto aakulu a chilengedwe komanso kumapereka chiwopsezo chachangu komanso chosasinthika kwa anthu (1, 2).Pamene mpweya wa CO2 wa mumlengalenga unakula kwambiri kuchoka pa 270 ppm (gawo pa milioni) koyambirira kwa zaka za m'ma 1800 kufika pa 401.3 ppm mu July 2015, mgwirizano wapadziko lonse wokhudza kubwezeretsanso mpweya wotulutsidwa ndi zochita za anthu wafika (3, 4).Kuti tizindikire kuyandikira kwa mpweya wa carbon, njira imodzi yomwe ingatheke ndikusamutsa kudalira kwa mafakitale amphamvu ndi mankhwala kuti achoke ku mafuta oyaka mafuta kupita kumalo ongowonjezedwanso monga dzuwa ndi mphepo (5-8).Komabe, kachigawo kakang'ono ka mphamvu kuchokera kumagwero ongowonjezwdwawo amangokhala 30% chifukwa cha kukhazikika kwawo pakanthawi, pokhapokha ngati njira zosungiramo mphamvu zazikulu zitapezeka (9).Chifukwa chake, m'malo mwake, kugwidwa kwa CO2 kuchokera kumagwero monga magetsi, kutsatiridwa ndi kusinthidwa kukhala zopangira mankhwala ndi mafuta, ndikotheka (9-12).Electrocatalytic CO2 reduction (ECR) pogwiritsa ntchito magetsi ongowonjezwdwa ndikuyimira njira yabwino kwambiri yanthawi yayitali chifukwa cha magwiridwe antchito ocheperako omwe amafunikira kuti atembenuke, momwe zinthu zowonjezeretsa zitha kupangidwa mosankha (13).Monga momwe tawonetsera m'chithunzi 1, pochita izi, electrochemical electrolyzer imatembenuza CO2 ndi madzi kukhala mankhwala ndi mafuta opangidwa ndi magetsi ongowonjezedwanso.Mafuta omwe amachokera amatha kusungidwa kwa nthawi yayitali ndipo amathanso kugawidwa kapena kudyedwa, kutulutsa CO2 ngati zinyalala zazikulu, zomwe zidzalandidwa ndikubwezeredwa ku reactor kuti atseke kuzungulira.Komanso, chifukwa chaing'ono molekyulu mankhwala feedstocks [mwachitsanzo, carbon monoxide (CO) ndi formate] kuchokera ECR angagwiritsidwe ntchito ngati zipangizo zovuta kwambiri kaphatikizidwe mankhwala.

Mafuta ndi mankhwala atha kupezedwa kuchokera ku ECR ndi kuzungulira kwa kaboni kotsekedwa koyendetsedwa ndi mphamvu zongowonjezwdwa monga dzuwa, mphepo, ndi hydro.Uinjiniya wama cell ndi uinjiniya wothandizira umagwira ntchito zazikulu zolimbikitsa kusankha, kuchita, komanso kuchita bwino kuti CO2 isanduke kukhala zinthu za C2+ zowonjezeredwa ndi mphamvu zambiri.

Komabe, CO2 ndi molekyu yokhazikika yokhazikika yokhala ndi chomangira cholimba cha C═O (750 kJ mol−1) (14), zomwe zimapangitsa kuti zikhale zovuta kutembenuka kwa electrochemical.Chifukwa chake, pamafunika chotchinga chachikulu choyambitsa, chomwe chimatsogolera kuzinthu zambiri zochulukirapo (15).Kuphatikiza apo, ECR mu electrolyte yam'madzi imaphatikizapo njira zambiri zosinthira ma elekitironi / pulotoni pamodzi ndi mitundu ingapo yamitundu yosiyanasiyana ndi zinthu (16-18), ndikupangitsa kuti ikhale yovuta kwambiri.Table 1 ikufotokoza mwachidule theka la electrochemical thermodynamic reaction of the main ECR products, including CO, methane (CH4), methanol (CH3OH), formic acid (HCOOH), ethylene (C2H4), ethanol (CH3CH2OH), ndi zina zotero, pamodzi ndi awo. zofananira mulingo wa redox (19).Nthawi zambiri, panthawi ya ECR, mamolekyu a CO2 amayamba kutsatiridwa ndi kuyanjana ndi ma atomu pamtunda wothandizira kupanga * CO2-, kutsatiridwa ndi kusamutsa kwapang'onopang'ono kwa ma protoni ndi/kapena ma elekitironi kupita kuzinthu zomaliza.Mwachitsanzo, CH4 amakhulupirira kuti imapanga kudzera m’njira zotsatirazi: CO2 → *COOH → *CO → *CHO → *CH2O → *CH3O → CH4 + *O → CH4 + *OH → CH4 + H2O (20).

Chithunzi 2A chikufotokozera mwachidule mphamvu ya Faradaic (FE) pansi pamitundu yosiyanasiyana yopangira (kachulukidwe kakali pano) kwa ma electrocatalysts a ECR, omwe amayimira kusankha kwazomwe zimachitika (21-43).Makamaka, ngakhale ma electrocatalyst apamwamba amatha kusintha CO2 kukhala zinthu za C1 (CO kapena formate) zokhala ndi 95% FE pansi pakupanga kwakukulu (> 20 mA cm−2 yamtundu wa H ndi> 100 mA cm− 2 ya cell cell) (9, 21, 22, 25, 28, 44, 45), yosankha kwambiri (> 90%) komanso kupanga bwino kwamankhwala ochulukirapo a multicarbon (C2 +) sikunachitike mpaka pano.Izi ndichifukwa choti kulumikizana ndi zinthu za C2+ kumafuna kufika ndi kutsatiridwa kwa mamolekyu angapo a CO2 pamwamba, kusinthika kwapang'onopang'ono, ndikuyika kwa malo (13).Kunena zachindunji, monga momwe tawonetsera mkuyu 2B, zotsatira zotsatila za * CO intermediates zimatsimikizira zomaliza za C2 + za ECR.Kawirikawiri, C2H6 ndi CH3COO- amagawana zofanana *CH2 zapakatikati, zomwe zimapangidwa kuchokera ku proton-coupled electron transfer step of *CO.Protonation ina ya *CH2 imapereka *CH3 yapakatikati, yomwe imatsogolera kupanga C2H6 kudzera *CH3 dimerization.Mosiyana ndi m'badwo wa C2H6, CH3COO− imapangidwa ndi kuyika kwa CO mu *CH2.The *CO dimerization ndi sitepe yodziwira mlingo wa C2H4, CH3CH2OH, ndi n-propanol (n-C3H7OH) mapangidwe.Pambuyo pa masitepe angapo a ma electron ndi ma protonation, * CO─CO dimer imapanga * CH2CHO pakati, yomwe imakhala ngati sitepe yosankha kusankha kwa C2H4 ndi C2H5OH.Kuonjezera apo, zinapezeka kuti kuchepetsa * CH2CHO ku C2H4 kuli ndi mphamvu zochepa zoletsa mphamvu kuposa kusintha * CH3CHO ku C2H5OH (46), zomwe zingafotokozere FE yapamwamba kwa C2H4 pa C2H5OH pazitsulo zambiri zamkuwa.Kuphatikiza apo, okhazikika a C2 okhazikika amatha kusamutsira ku n-C3H7OH kudzera pakuyika kwa CO.Njira zovuta komanso zosalamulirika zomwe zimachitika panthawi ya C2 + kupanga mankhwala zimachitika makamaka chifukwa cha zololeza zambiri kumalo opangira ma protonation, komanso kukhudzidwa kwa gawo la nonelectrochemical (19, 47).Momwemonso, mapangidwe a electrocatalysts osankhidwa kwambiri ndizofunikira kuti apange mapangidwe apadera a C2 + pa zokolola zambiri.Mukuwunikaku, tikufuna kuwunikira zomwe zapita patsogolo posachedwa pamapangidwe a electrocatalyst posankha C2+ kupanga zinthu kudzera pa ECR.Timaperekanso chidule cha kumvetsetsa kwamakina okhudzana.Mapangidwe a Electrode ndi riyakitala adzatsindikitsidwanso kuti awonetse momwe angakwaniritsire ntchito yabwino, yokhazikika, komanso yayikulu ya ECR.Komanso, tidzakambirana zovuta zomwe zatsala ndi mwayi wamtsogolo wa kutembenuka kwa electrochemical kwa CO2 kukhala mankhwala owonjezera a C2 +.

(A) The FE pansi pa mitengo yosiyanasiyana yopanga (kachulukidwe kakali pano) kwa ma electrocatalysts a ECR (21-43, 130).(B) Njira zambiri zotheka za C2 + pa ECR.Idapangidwanso ndi chilolezo chochokera ku American Chemical Society (47).

Kusintha kwa Electrocatalytic kwa CO2 kukhala mafuta opangira mankhwala ndi masheya ndi ukadaulo wotheka kuti ukwaniritse kuzungulira kwamphamvu kwa mpweya (11).Komabe, FE ya C2 + mankhwala akadali kutali ndi ntchito zothandiza, kumene zopangira zamakono zimalola kupanga zinthu za C2 zozungulira 60% FE (13, 33), pamene kupanga C3 kumakhala kochepa kuposa 10% FE (48, 49).Kuphatikizika kochepetsetsa kwa CO2 kuzinthu za C2+ kumafuna zopangira zosasinthika zokhala ndi zida zolumikizidwa bwino za morphological ndi zamagetsi (50, 51).Malo othandizira amayenera kusokoneza ubale wokulirapo pakati pa apakati (47, 52, 53).Komanso, kuti mukwaniritse mapangidwe a mgwirizano wa C─C, zomwe zimakhudzidwa ndizomwe zimayambira pa chothandizira ziyenera kukhala zoyandikana wina ndi mzake.Kuphatikiza apo, njira yochokera pakatikati yomwe idalowetsedwa kupita ku chinthu china cha C2+ iyenera kuyendetsedwa bwino chifukwa cha masitepe angapo othandizidwa ndi ma electron.Poganizira zovuta kwambiri za CO2 kuchepetsa kuzinthu za C2+, ma electrocatalysts ayenera kukonzedwa mosamala kuti awonjezere kusankha.Malinga ndi mitundu yapakatikati ndi kapangidwe ka mankhwala, timagawa zinthu za C2+ kukhala ma multicarbon hydrocarbons ndi oxygenates (4, 54).Kuti muyandikire ma electrocatalysts amphamvu kwambiri popanga mamolekyu a C2+, njira zingapo zothandizira, monga heteroatom doping, crystal facet regulation, alloy/dealloying, oxidation state tuning, and surface ligand control, zasonyezedwa (35, 41, 55-61) .Kukonzekera koyenera kuyenera kuganizira mozama zomwe tatchulazi ndikuwonjezera phindu.Kupanda kutero, kumvetsetsa zomwe masamba amasamba omwe amatsogolera kumayendedwe apadera otere atha kuwunikiranso kamangidwe kake kothandizira kaphatikizidwe ka C─C.Chifukwa chake, momwe mungapangire chothandizira cha ECR kuzinthu zinazake (ma multicarbon hydrocarbons ndi oxygenates) ndi njira yofananirayi tikambirana mgawoli.

Ma hydrocarbon a C2+, monga C2H4, ndi mankhwala ophatikizika amafakitale osiyanasiyana amankhwala, monga kupanga polyethylene (62, 63).Kupatula apo, amatha kugwiritsidwa ntchito ngati mafuta akuwotchera kapena kusakaniza gasi (12).Hydrogenation ya CO (Fischer-Tropsch synthesis) ndi CO2 yakhala ikugwiritsidwa ntchito popanga ma hydrocarbon a C2+ kwa nthawi yayitali m'mafakitale koma amatsutsidwa ndi kugwiritsa ntchito mphamvu zambiri komanso kukhudzidwa kwachilengedwe (64).Mosiyana kwambiri, kuchepetsa kwa electrochemical CO2 pogwiritsa ntchito mphamvu zowonjezera kumapereka njira yoyera komanso yokhazikika.Khama lalikulu lapangidwa kuti apange ma electrocatalysts ogwira mtima ku C2+ hydrocarbons (32, 33, 65-70).

Ma electrocatalysts a Bimetallic akhala akufufuzidwa kwambiri kuti athetse mgwirizano wowonjezereka panthawi ya kutembenuka kwa electrochemical CO2, yomwe ingakhazikitse fungulo lapakati ndi kuchepetsa mphamvu yowonjezera, motero, kuonjezera kusankha (71-74).Ngakhale zida zingapo za aloyi kuphatikiza Au-Cu, Ag-Cu, Au-Pd, ndi Cu-Pt zasonyezedwa kuti zikupanga bwino kwambiri C1 pokhazikika pakatikati (73, 75), mphamvu ya alloy ku C2+ hydrocarbon mapangidwe akuwoneka. kukhala wovuta kwambiri (76).Mwachitsanzo, mu Cu-Ag bimetallic system, kugawa kwazinthu kumatha kuwongoleredwa mosavuta ndikusintha chiŵerengero cha atomiki cha Ag ndi Cu (77).Zitsanzo zamtundu wa Cu-rich zimakondedwa popanga hydrocarbon, pomwe zinthu zapamtunda wa Ag-rich one zimayendetsedwa ndi CO, kuwonetsa kufunikira kwa chiŵerengero cha atomiki kwa ma electrocatalyst a alloyed ECR.Zotsatira za geometric zomwe zimayambitsidwa ndi makonzedwe a atomiki amderalo zimatha kukhudza kwambiri mphamvu zomangira zapakati.Gewirth ndi ogwira nawo ntchito (36) adawonetsa kuti Cu-Ag alloys kuchokera ku electrodeposition yoyendetsedwa ndi zowonjezera amawonetsa ~ 60% FE kwa C2H4 mu electrolyzer yothamanga ya alkaline (Mkuyu 3, A ndi B).Pamenepa, kusankha kokongoletsedwa kwa C2H4 kungathe kupezedwa ndi morphology ndi Ag-loading tuning.Masamba a Ag amakhulupilira kuti amasewera gawo lothandizira kupanga CO pa ECR.Kenako, kupezeka kwapakati kwa CO kungathandize kulumikizana kwa C─C ku Cu yoyandikana nayo.Kupatula apo, Ag imathanso kulimbikitsa mapangidwe a Cu2O panthawi ya Cu-Ag catalyst synthesis (mkuyu 3C), zomwe zimapangitsa kuti C2H4 ipangidwe bwino.Synergy iyi imatsegula mwayi watsopano wopanga zida zolumikizira C─C.Kuphatikiza apo, kusanganikirana kwa zitsulo zosiyanasiyana mu alloy system kumatha kudziwanso kugawa kwazinthu za ECR.Pogwiritsa ntchito aloyi ya Pd-Cu monga chitsanzo (mkuyu 3D), Kenis ndi ogwira nawo ntchito (71) adawonetsa kuti chothandizira cha Pd-Cu chosiyana ndi gawo chikhoza kupereka kusankha kwakukulu (~ 50%) kwa C2H4 poyerekeza ndi kulamulidwa ndi kusokonezeka. anzawo.Malinga ndi chiphunzitso cha d-band, nthawi zambiri, chitsulo chosinthira chokhala ndi malo otsika a d-band chimawonetsa kumangika kofooka kwa in situ zopangidwa pakati pazitsulo (78).Ngakhale gawo olekanitsidwa Pd-Cu aloyi anasonyeza ofanana chothandizira selectivity ndi ntchito kwa NKHA ndi Cu nanoparticles (NPs), izo anapereka osiyana kotheratu kumanga mphamvu kwa intermediates ndi Pd ikukonzekera.Monga momwe tawonetsera mkuyu 3E, gawo lolekanitsidwa la Cu-Pd alloy linasonyeza malo otsika kwambiri a d-band, pamene a Cu NP ndi apamwamba kwambiri.Zikusonyeza kuti aloyi yolekanitsidwa ndi gawo la Cu-Pd inali ndi mphamvu zotsika kwambiri zomangira CO.Izi zikutanthauza kuti mawonekedwe a geometric ndi mawonekedwe amatha kukhala ndi gawo lalikulu kuposa mphamvu yamagetsi pakuwongolera kusankha kwa hydrocarbon mu mlandu wopatukana wa Cu-Pd alloy.Mpaka pano, mkuwa wokhawokha kapena aloyi wopangidwa ndi mkuwa umasonyeza kusankhidwa kwapamwamba ndi ntchito ya electrochemical kuchepetsa CO2 mpaka C2 + hydrocarbons.Chifukwa chake, ndikofunikira kwambiri kupanga makina opangira ma electrocatalyst a C2 + hydrocarbon kupanga kuchokera ku ECR.Mouziridwa ndi CO2 hydrogenation, kafukufuku woyambirira adawonetsa kuti aloyi a Ni-Ga okhala ndi magawo osiyanasiyana atha kugwiritsidwa ntchito m'badwo wa C2H4 (79).Zinawonetsa kuti filimu ya Ni5Ga3 ikhoza kuchepetsa CO2 ku C2H4 ndi ethane (C2H6).Ngakhale FE yopita ku C2+ ma hydrocarbons ndi yocheperapo 5%, ikhoza kutsegula mizere yatsopano yowunikira ma electrocatalyst kulumikiza ku C─C kutengera mphamvu ya alloy.

(A mpaka C) Cu-Ag bimetallic catalysts zopangidwa ndi electrodeposition yoyendetsedwa ndi zowonjezera: (A) scanning electron microscopy (SEM) ya Cu waya, Cu-Ag poly, ndi Cu-Ag waya ndi (B) yogwirizana ndi C2H4 FE.(C) EXAFS adawonetsa kuti waya wa Cu-Ag anali wosakanikirana mosiyanasiyana ndipo Cu(I) oxide idaperekedwa.(A) mpaka (C) amapangidwanso ndi chilolezo kuchokera ku American Chemical Society (36).(D ndi E) Zothandizira za Cu-Pd zokhala ndi mitundu yosiyanasiyana yosakanikirana: (D) Chithunzi, zithunzi za ma electron microscopy (TEM), ndi mamapu amagetsi amagetsi amagetsi a Cu-Pd okonzedwa, osokonezeka, komanso olekanitsidwa ndi magawo (E). ) pamwamba pa valence band photoemission spectra ndi d-band center (mzere wolunjika) wa Cu-Pd alloys wokhudzana ndi msinkhu wa Fermi.(D) ndi (E) adapangidwanso ndi chilolezo kuchokera ku American Chemical Society (71).kapena, mayunitsi osagwirizana.

Kupatula aloyi zotsatira, kusokoneza mayiko makutidwe ndi okosijeni ndi mfundo ina yaikulu kuchunira ntchito ya electrocatalysts, amene angakhudze m'dera dongosolo lamagetsi zinthu.Chitsanzo choyamba cha ma oxidation state tuning cha chothandizira ndicho kugwiritsa ntchito zinthu zochokera ku oxide.Mitundu yotsalira ya okosijeni yomwe ili pamtunda kapena pansi pa chothandizira pambuyo pochepetsera in situ imatha kuwongolera mkhalidwe wa okosijeni wapakati pazitsulo.Mwachitsanzo, Cu plasma-oxidized Cu inasonyeza kusankhidwa kwa 60% ku C2H4, yomwe inalembedwa ndi Cu + (37) yosagwira kuchepetsa.Kuti titsimikizire kuti Cu + ndiye gawo lofunikira la kusankha kwapamwamba kwa ethylene, tidachita zoyeserera pogwiritsa ntchito plasma yosiyana (mkuyu 4A).In situ hard x-ray absorption spectroscopy inasonyezanso kuti ma oxides otsalira mu (sub) pamwamba wosanjikiza ndi osasunthika motsutsana ndi kuchepetsedwa, ndi kuchuluka kwa mitundu ya Cu+ yomwe yatsala pambuyo pa ola la 1 kuchepetsedwa pa kuthekera kwakukulu kwa -1.2 V motsutsana ndi kusinthika. hydrogen electrode (RHE).Kuphatikiza apo, electroredeposition yamkuwa kuchokera ku sol-gel copper oxychloride idatsimikiziranso kuti mitundu yokhazikika ya Cu + imatha kusintha kusankha kwa C2H4 (61).Mkhalidwe wa okosijeni wa chothandizira chamkuwa pansi pa kuthekera kosiyanasiyana kogwiritsidwa ntchito unkatsatiridwa pogwiritsa ntchito mawonekedwe osunthika mu situ ofewa a x-ray a mayamwidwe.Gawo loyamba la kusintha kuchokera ku Cu2 + kupita ku Cu + ndilofulumira kwambiri;komabe, kuchepetsedwa kwina kwa electrochemical kwa mitundu ya Cu + mpaka Cu0 ndikocheperako.Pafupifupi 23% ya mitundu ya Cu + imakhalabe ngakhale pambuyo pa ola la 1 kuchepetsedwa kosalekeza pansi pa −1.2 V motsutsana ndi RHE (mkuyu 4B).Kafukufuku wamakina adawonetsa kuti mawonekedwe apakati pa Cu + ndi Cu0 amatsogolera kukopeka kwamagetsi pakati pa oyimira pakati popeza C atomu ya *CO @ Cu + ili ndi charger yabwino, pomwe ya *CO @ Cu0 imakhala yoyipa (80), yomwe imalimbikitsa C─C kupanga chomangira motero kumapanga C2+ hydrocarbons.Kuphatikiza pa zinthu zopangidwa ndi oxide, copper nitride (Cu3N) idagwiritsidwanso ntchito kukwaniritsa (sub) pamwamba pa mitundu ya Cu+ kuti achepetse chotchinga champhamvu cha *CO (81).Kuonjezera apo, poyerekeza ndi Cu3-derived Cu, Cu3-derived Cu + mitundu imakhala yolimba kwambiri (Mkuyu 4C).Chotsatira chake, chothandizira cha mkuwa chochokera ku nitride chimasonyeza FE ya 39 ± 2% ya C2H4, yoposa Cu yoyera (~ 23%) ndi Cu (~ 28%).Mofanana ndi Cu+/Cu catalytic system yomwe tatchulayi, boron yagwiritsidwa ntchito ngati heteroatom dopant kuyambitsa ndi kukhazikika Cuδ+ (41).Pafupifupi makutidwe ndi okosijeni amkuwa amatha kuwongoleredwa kuchokera ku +0,25 mpaka +0.78 posintha kuchuluka kwa boron dopant.Kachulukidwe kachulukidwe ka mayiko adawonetsa kuti ma elekitironi amasamutsidwa kuchoka ku mkuwa kupita ku boron, zomwe zimatsogolera ku malo amkuwa omwe amapangidwa ndi dopant.Mkuwa wa boron-doped umasonyeza mphamvu yowonjezera ya *CHO yapakatikati, motero, inalepheretsa njira yopita kuzinthu za C1.Komanso, akhoza kuonjezera selectivity kwa multicarbon hydrocarbons ndi kuchepetsa *CO dimerization anachita mphamvu (mkuyu. 4D).Mwa kukhathamiritsa pafupifupi padziko makutidwe ndi okosijeni dziko mkuwa, mkulu C2 FE wa ~ 80% ndi ~ 53% C2H4 chingapezeke pansi pafupifupi mkuwa makutidwe ndi okosijeni boma la +0.35 (mkuyu. 4E).Mpaka pano, malo omwe akugwira ntchito pamkuwa adadziwika kuti Cu0, Cuδ+, ndi / kapena mawonekedwe awo a ECR mu maphunziro osiyanasiyana (39, 41, 42, 81, 82).Komabe, tsamba logwira ntchito ndi liti lomwe likukambidwabe.Ngakhale chothandizira cha heteroatom doping-induced Cuδ+ chasonyezedwa kuti chikugwira ntchito kwambiri pa ECR kuzinthu za C2+, mphamvu ya synergistic yochokera pakuwonongeka kopangidwa nthawi imodzi ndi ma interfaces iyeneranso kuganiziridwa.Chifukwa chake, mawonekedwe amtundu wa operando ayenera kupangidwa kuti azindikire malo omwe ali pamtunda wamkuwa ndikuyang'anira momwe angasinthire malo omwe akugwira ntchito.Kupatula apo, kukhazikika kwa mkuwa wopangidwa bwino ndi nkhawa ina pansi pamikhalidwe yochepetsera ma electrochemical.Momwe mungapangire zothandizira ndi masamba okhazikika a Cuδ+ ndizovuta.

(A) Chidule cha kusankha kwa C2H4 kwamitundu yosiyanasiyana yamkuwa yopangidwa ndi plasma.Idasindikizidwanso ndi chilolezo chochokera ku Nature Publishing Group (37).Mipiringidzo yayikulu, 500 nm.(B) Ratio ya Cu oxidation states poyerekezera ndi nthawi yochitira -1.2 V motsutsana ndi RHE mu electroredeposited copper.Zapangidwanso ndi chilolezo chochokera ku Nature Publishing Group (61).(C) Chiŵerengero cha mitundu ya Cu + yokhala ndi nthawi yochitapo kanthu pa -0.95 V motsutsana ndi RHE mu Cu-on-Cu3N kapena Cu-on-Cu2O.Zapangidwanso ndi chilolezo chochokera ku Nature Publishing Group (81).(D) Doping ya Boron inatha kusintha mphamvu ya adsorption ya CO pamtunda wamkuwa ndikutsitsa mphamvu ya CO─CO dimerization.1[B], 2[B], 3[B], 4[B], ndi 8[B] amatanthawuza kuchuluka kwa doping ya boron yapansi panthaka muzothandizira zamkuwa, zomwe zinali 1/16, 1/8, 3/ 16, 1/4, ndi 1/2 motsatana.(E) Ubale wapakati pa oxidation state ndi FE wa C2 kapena C1 zopangira zamkuwa za boron-doped copper.(D) ndi (E) apangidwanso ndi chilolezo chochokera ku Nature Publishing Group (41).(F) Zithunzi za SEM za zojambula zamkuwa zokhala ndi makulidwe osiyanasiyana amafilimu a Cu2O kale (pamwamba) ndi pambuyo (pansi) ECR.Idapangidwanso ndi chilolezo chochokera ku American Chemical Society (83).

Kupatula mawonekedwe amagetsi, zida zochokera ku oxide zimathanso kutsogolera ku morphology kapena kusinthika kwadongosolo panthawi yochepetsera in situ.Kuchokera pamalingaliro a morphology kapena kapangidwe kake, kupititsa patsogolo kagwiridwe kake ka electrochemical kwa ma electrocatalysts opangidwa ndi oxide akuti kudapangidwa chifukwa chopanga malire ambewu, m'mphepete, ndi masitepe (83-85).Yeo ndi ogwira nawo ntchito (83) adanena za kusankha C─C kugwirizana pa electrodeposited Cu2O mafilimu ndi makulidwe osiyana (Fig. 4F).In situ Raman spectroscopy inawulula kuti pamwamba pa mafilimu a Cu2O adachepetsedwa kukhala Cu0 yokhazikika yachitsulo panthawi ya ECR (83).Zotsatira zake, zitsulo za Cu0 zatsimikiziridwa kuti ndizothandiza kwambiri m'malo mwa mitundu ya Cu + kapena mawonekedwe a Cu +/Cu0.Pochepetsa Cu2O kukhala zitsulo Cu0, chothandiziracho chikhoza kukhala masitepe, m'mphepete, ndi masitepe.Zinanenedwa kuti masitepe opangidwa ndi m'mphepete mwake amakhala otanganidwa kwambiri kuposa mabwalo, omwe amachokera kumangiridwe awo amphamvu ndi * CO, omwe amatha kupititsa patsogolo hydrogenate * CO kupita ku * CHO kapena * CH2O.Kupatula apo, ma atomu a m'mphepete mwa Cu ndiwolimbikitsa kulimbikitsa *CHO ndi *CH2O mapangidwe.Ntchito yam'mbuyomu idanenanso kuti *CHO ndi *CH2O ophatikizana ndi abwino kwambiri pakulumikizana kwa C─C kuposa *CO mu kinetics (86).Poyang'anira mawonekedwe a pamwamba, mphamvu za chemisorption za *CHO ndi *CH2O zapakati zitha kukonzedwa.Mu phunziro ili, olembawo adapeza kuti FE ya C2H4 inatsika kuchokera ku 40 mpaka 22% pamene iwo anawonjezera makulidwe a Cu2O filimu yopyapyala kuchokera ku 0.9 mpaka 8.8 μm.Izi ndichifukwa cha ndende ya otsika yogwirizana Cu kuti kuchuluka ndi kuwonjezeka Cu2O makulidwe.Ma atomu osalumikizana bwinowa amatha kumangika mwamphamvu ndi H ndipo, motero, amakondedwa kwambiri ndi kusintha kwa haidrojeni kuposa kulumikizana kwa C─C.Ntchitoyi inasonyeza kuti chothandizira chamkuwa chochokera ku oxide chingathe kupititsa patsogolo kwambiri kusankhidwa kwa C2H4 kudzera m'mapangidwe amtundu wa morphology m'malo moyambitsa mitundu ya Cuδ +.Pogwiritsa ntchito chothandizira chopangidwa ndi okusayidi, ethane (C2H6) yapangidwanso mosankhidwa mothandizidwa ndi palladium (II) chloride (PdCl2) yowonjezera mu electrolyte (34).Zinawonetsa kuti adsorbed PdClx pamwamba pa Cu2O-derived Cu idachita gawo lofunikira pakusintha kwa C2H6.Mwachindunji, CO2 poyamba inachepetsedwa kukhala C2H4 pa Cu2O-derived active Cu sites, ndiyeno C2H4 yomwe inapangidwa ikanakhala hydrogenated mothandizidwa ndi adsorbed PdClx kupanga C2H6.FE ya C2H6 idakwera kuchoka pa <1 mpaka 30.1% mothandizidwa ndi PdCl2.Ntchitoyi ikuwonetsa kuti kuphatikiza kwa chothandizira chodziwika bwino cha ECR ndi chowonjezera cha electrolyte kungatsegule mipata yatsopano yamtundu wina wa C2 +.

Kapangidwe ka morphology ndi/kapena kamangidwe kakuyimira njira ina yosinthira kusankhidwa kothandizira ndi zochitika.Kuwongolera kukula, mawonekedwe, ndi mawonekedwe owonekera a chothandizira kwawonetsedwa kwambiri pakuwongolera magwiridwe antchito a ECR (58, 87, 88).Mwachitsanzo, Cu(100) facet imakondedwa kwambiri m'badwo wa C2H4, pomwe chothandizira cha Cu(111) ndi methane (CH4) (87).Pakufufuza kwa Cu nanocrystals ndi maonekedwe ndi makulidwe osiyanasiyana, Buonsanti ndi ogwira nawo ntchito (58) adawonetsa kudalira kwapang'onopang'ono kwa C2H4 mu nanocrystals zamkuwa zooneka ngati cube (mkuyu 5A).Mwachidziwitso, cubic Cu nanocrystals adawonetsa zochitika zapamwamba za C2H4 ndi kusankha kuposa Cu nanocrystals yozungulira chifukwa cha kutchuka kwa mbali (100).Kukula kocheperako kwa cubic Cu kumatha kupereka ntchito zapamwamba chifukwa chakuchulukirachulukira kwa malo ocheperako, monga ngodya, masitepe, ndi ma kink.Komabe, chemisorption yamphamvu ya malo ocheperako idatsagana ndi kusankha kwapamwamba kwa H2 ndi CO, zomwe zimapangitsa kuti hydrocarbon FE ikhale yotsika.Kumbali ina, chiŵerengero cha malo a m'mphepete mwa malo opangira ndege chinachepa ndi kuwonjezeka kwa tinthu tating'onoting'ono, zomwe zimakhudzanso ntchito ya C2H4 kupanga.Olembawo adawonetsa kuti ma nanocubes amkuwa amkuwa okhala ndi 44-nm m'mphepete kutalika adawonetsa kusankhidwa kwapamwamba kwambiri kwa C2H4 chifukwa chakuwongolera bwino pakati pa kukula kwa tinthu ndi kachulukidwe ka masamba am'mphepete.Kuphatikiza apo, morphology imathanso kukhudza pH yakomweko komanso zoyendera zambiri pa ECR.Zasonyezedwa kuti pH yam'deralo pafupi ndi catalyst surface, yomwe imayambitsidwa ndi in situ yopangidwa ndi OH-, imapondereza njira yokhudzana ndi proton.Zotsatira zake, mapangidwe a C2+ hydrocarbon kudzera mu * CO dimerization atha kupitilizidwa, ndipo CH4 yopangidwa kudzera pa *COH yapakatikati ikhoza kuletsedwa.Mkuwa wa nanowire arrays (mkuyu. 5B) asonyezedwa kuti akwaniritse pH yapafupi (68).Monga electrolyte yomwe imagwiritsidwa ntchito nthawi zambiri, njira ya CO2 saturated potassium bicarbonate (KHCO3) idzasokoneza mwamsanga OH-(HCO3− + OH− = CO32− + H2O) ndikuchepetsa pH yakomweko.Ndi microstructure elongated, kufalikira kwa HCO3- mu Cu nanowire arrays akhoza kufooketsa mwanjira ina kotero kuti neutralization zotsatira za OH-zako zidzaponderezedwa pamlingo wina.Pamaziko a mfundo yofanana, ma meshes mkuwa ndi masopores ndendende ankalamulira (mkuyu. 5C) anasonyeza kumatheka FE kwa C2H4 kapena C2H6 kupanga (32).Zinawonetsa kuti pH yam'deralo pamtunda wa elekitirodi ikhoza kuonjezedwa pochepetsa kukula kwa pore, zomwe zimapangitsa kuchepa kwa C1 product FE ndikuwonjezera C2 product FE.Kupatula apo, pakukulitsa kuya kwa pore, chinthu chachikulu chochepetsera chikhoza kusinthidwa kuchokera ku C2H4 mpaka C2H6.FE ya C2H6 inali yokwera mpaka 46%.Popeza kuti mankhwalawo atsekeredwa mkati mwa pores pa ECR, nthawi yosungirako nthawi yayitali ya mafungulo oyambira chifukwa cha ma pores akuya afotokozedwa ngati chifukwa chachikulu cha kusankha kwakukulu kwa C2 hydrocarbon yodzaza.CuI-derived Cu nanofibers anasonyezanso kusankha kwakukulu kwa C2H6 (FE = 30% pa -0.735 V motsutsana ndi RHE) (89).The anisotropic morphology ndi kuuma kwapamwamba kwa CuI-derived Cu nanofibers kumatha kupititsa patsogolo kutsekeka kwa H2 yotengedwa ndikuwonjezera FE ya C2H6.

(A mpaka C) morphology kapena zotsatira zake.(A) Kachulukidwe ka ma atomu (mzere wakumanzere) ndi chiŵerengero cha maatomu m’mphepete mwa nyanja (Nedge) ndi ma atomu pa (100) ndege (N100) (mzere wa kumanja) mogwirizana ndi kutalika kwa m’mphepete (d).Adapangidwanso ndi chilolezo chochokera kwa John Wiley ndi Ana (58).(B) Dongosolo la morphology linapangitsa pH kusintha.Adapangidwanso ndi chilolezo chochokera kwa John Wiley ndi Ana (68).(C) Kusankhidwa kwazinthu zamkuwa za mesopore zokhala ndi ma pore osiyanasiyana komanso kuya kwake.Adapangidwanso ndi chilolezo chochokera kwa John Wiley ndi Ana (32).(D mpaka H) Ligand zotsatira.(D ndi E) ECR pa copper nanowire (Cu NW) yokhala ndi mitundu yosiyanasiyana ya ma amino acid (D) kapena zosinthira (E) pa −1.9 V. Inapangidwanso ndi chilolezo chochokera ku Royal Society of Chemistry (35).(F) Mitengo yopangira C2H4 mu ma electrolyte osiyanasiyana a halide okhala ndi kuthekera kosiyanasiyana kwa adsorption pa Cu(35).Idapangidwanso ndi chilolezo chochokera ku American Chemical Society (91).NHE, wamba wa hydrogen electrode.(G) FE ya C2H4 ndi CO mumagulu osiyanasiyana a KOH electrolytes ndi (H) Tafel otsetsereka a C2H4 mumagulu osiyanasiyana a KOH electrolytes.(G) ndi (H) amapangidwanso kuchokera ku American Association for the Advancement of Science (AAAS) (33).

Kusintha kwapamwamba kwa catalyst pogwiritsa ntchito mamolekyu ang'onoang'ono ndi njira ina yodziwika bwino yopititsira patsogolo magwiridwe antchito a electrochemical a ECR.Njirayi imatha kukhudza microenvironment pafupi ndi chothandizira pamwamba, chomwe chingakhazikitse mafungulo ofunikira chifukwa cha kugwirizana pakati pa ligand pamwamba ndi apakatikati.Amine adanenedwa ngati wosintha kulimbikitsa ECR (35).Ma amino acid osiyanasiyana, kuphatikiza glycine (Gly), dl-alanine (Ala), dl-leucine (Leu), dl-tryptophan (Tyr), dl-arginine (Arg), ndi dl-tryptophan (Trp), adafufuzidwa kuti phunzirani zotsatira zake pa nanowires zamkuwa (35).Monga momwe tawonetsera mkuyu 5D, ma ligand onse a amino acid amatha kupititsa patsogolo kusankhidwa kwa C2 + hydrocarbons.Kupititsa patsogolo kotereku kukuwonetsa kuti ─COOH ndi ─NH2 magulu ogwira ntchito mu amino acid mwina ndiwo omwe amachititsa kuti ECR isankhidwe bwino.Malipoti am'mbuyomu adawonetsa kuti kutsatsa kwa ma amino acid pamtunda wa Cu kudatheka kudzera m'magulu onse a ─COOH ndi ─NH2 (35, 90).Stearic acid (C17H35COOH, RCO2H), yomwe ili ndi gulu la ─COOH lokha, linasankhidwa kuti lizindikire udindo wa ─COOH.Zosintha zina, monga a-anthraquinone diazonium salt (AQ), o-nitrobenzene diazonium salt (PhNO2), ndi dodecyl mercaptan (C12H25SH, RSH), zomwe zilibe magulu a ─COOH kapena ─NH2, adafufuzidwanso.Komabe, zonsezi sizinali zabwino kwa C2 + hydrocarbon FE kusintha (mkuyu 5E).Kuwerengera kwamalingaliro kunawonetsa kuti magulu a ─NH3+ mu adsorbed zwitterionic glycine amatha kukhazikika *CHO pakati pakatikati chifukwa cha kuyanjana kwawo mwamphamvu, monga ma hydrogen bond.Kuyambitsa ma ion halide mu electrolyte ndi njira ina yosinthira zopangira (91, 92).Monga momwe tawonetsera mkuyu 5F, chiwerengero cha C2H4 chopanga pa plasma-activated Cu chikhoza kuwonjezeka kwambiri mothandizidwa ndi zowonjezera za halide.Zinawonetsedwa kuti I− ion imagwira ntchito kwambiri kuposa Br- ndi Cl-, mogwirizana ndi mphamvu zofananira za I-, Br-, ndi Cl- pa Cu(100) facet (91).Kupatula ma halides, hydroxide ion idawonetsanso zotsatira zabwino pakusankha kwa C2H4.Posachedwapa, Sargent ndi ogwira nawo ntchito (33) adanena za kutembenuka kwa CO2-to-C2H4 ndi ~ 70% FE pogwiritsa ntchito concentrated potassium hydroxide (KOH) electrolyte (mpaka 10 M) mu selo loyenda.Monga momwe tawonetsera mkuyu 5G, kuthekera koyambira kwa CO ndi C2H4 mu 10 M KOH electrolyte kunali kochepa kwambiri poyerekeza ndi 1 M KOH.Komanso, malo otsetsereka a Tafel (mkuyu 5H) a C2H4 mapangidwe anachepa ndi kuwonjezeka kwa hydroxide concentration (135 mV zaka khumi−1 mu 1 M KOH ndi 65 mV zaka khumi-1 mu 10 M KOH), kutanthauza kusintha kwa mlingo wonse- kudziwa sitepe.Zotsatira za Density functional theory (DFT) zatsimikizira kuti kupezeka kwa concentrated hydroxides kumatha kutsitsa mphamvu yomangirira ya CO yapakatikati komanso kukulitsa kusamvana pakati pa maatomu awiri a kaboni mu adsorbed OCCO intermediate.Zotsatira zake, OCCO wapakatikati idzakhalanso yokhazikika kudzera mumphamvu ya dipole yokopa, zomwe zimatsogolera kutsika kwamphamvu yotchinga mphamvu ya CO dimerization, zomwe zidzasintha magwiridwe antchito onse.

C2+ oxygenates monga ethanol (CH3CH2OH) ndi gulu lina lalikulu la zinthu zamtengo wapatali za ECR.Kaphatikizidwe ka mafakitale a ethanol ndi njira yogwiritsa ntchito mphamvu zambiri, yomwe imadyanso ethylene kapena zakudya zaulimi (40).Chifukwa chake, kupanga electrocatalytic ya ethanol kapena ma C2 + oxygenates kuchokera ku CO2 kumapanga nzeru zambiri zachuma komanso zachilengedwe.Popeza ethanol m'badwo ECR nawo penultimate wapakatikati ndi C2H4 kuti ndi *C2H3O (43), kusankha hydrogenation wa wapakatikati akhoza kusintha ECR njira kuchokera C2H4 kuti alcohols (64).Komabe, m'makina ambiri, kusankha kwa C2 + oxygenates ndikotsika kwambiri kuposa ma hydrocarbons (31, 37, 39, 41, 42, 67).Choncho, m'chigawo chino, tidzawonetsa njira zopangira electrocatalyst zomwe zingathe kukwaniritsa C2 + oxygenate FE yoposa 25%.

Monga tafotokozera pamwambapa, makina opangidwa bwino a bimetallic amatha kusintha kusankhidwa ndi ntchito za C2 + hydrocarbon kupanga.Njira yofananira koma yosagwirizana yagwiritsidwanso ntchito kupititsa patsogolo ntchito ya electrocatalytic ya C2 + oxygenates (38, 93, 94).Mwachitsanzo, zopangira za Ag-incorporated Cu-Cu2O zidawonetsa kusankhidwa kwa ethanol, ndipo ethanol FE yapamwamba kwambiri inali 34.15% (95).Malire a biphasic mu gawo losakanikirana la Ag-Cu aloyi, m'malo mwa chiŵerengero cha atomiki cha Ag/Cu, adadziwika kuti ndiye chinthu chofunikira kwambiri pakusankha kupanga kwa ethanol.Popeza malo a Cu ali pafupi kwambiri ndi malo a Ag mu ndondomeko yosakanikirana ndi gawo (Ag-Cu2OPB), kupanga mapangidwe a ethanol intermediates kwa gawo losakanikirana lachitsanzo likhoza kukwezedwa poyerekeza ndi gawo lolekanitsidwa (Ag-Cu2OPS). ), zomwe zimapangitsa kuti pakhale kutulutsa bwino kwa ethanol.Kupatula ethanol, Cu-Ag bimetallic NPs zasonyezedwanso kuti zisinthe CO2 kukhala acetate ndi kuwonjezera kwa benzotriazole (93).Pa -1.33 V motsutsana ndi RHE, FE ya acetate inali 21.2%.Njira ziwiri zomwe zingatheke zinaperekedwa pankhaniyi: Imodzi idakhazikitsidwa ndi CO dimerization, ndipo ina ili pa kuyika kwa CO, kuwonetsa mbali yofunika kwambiri ya CO mapangidwe apakatikati pamasamba a Ag.Kuwona kofananako kunanenedwa mu Cu-Zn catalysts (mkuyu 6, A ndi B) kwa kupanga ethanol (38).Mwa kukonza zomwe zili mu Zn mu Zn-Cu alloyed catalysts, chiŵerengero cha ethanol ndi C2H4 FE chikhoza kuyendetsedwa bwino pakati pa 0.48 mpaka 6, kutanthauza kufunikira kwa malo osinthika a CO kwa C2 + mapangidwe a oxygenate.Kupanga ma catalysts alloyed kungayambitse kupsinjika kwa zinthu za matrix, zomwe sizingafuneke nthawi zina.Chifukwa chake, njira yolunjika yopita kuzinthu zopangira bimetallic ikhoza kukhala yoyenera pazinthu zina zomwe mukufuna.Jaramillo ndi ogwira nawo ntchito (96) adapanga makina osavuta a Au-Cu bimetallic, opangidwa ndikuyika mwachindunji ma NPs agolide pa polycrystalline Cu zojambulazo, kuti afufuze zotsatira za tandem catalysis.Bimetallic Au-Cu idawonetsa kusankhira kolumikizana ndikuchita ku C2+ mowa, kupitilira mkuwa woyenga ndi golide, ndi aloyi ya Au-Cu.Poyerekeza ndi Cu zojambulazo, bimetallic Au-Cu dongosolo anasonyeza kuwonjezeka m'dera CO ndende chifukwa cha kukhalapo kwa Au NPs (mkuyu. 6C) amene anali yogwira CO m'badwo.Popeza golide sagwira ntchito pochepetsa CO, kuchuluka kwa mowa kwa C2+ pa Au-Cu bimetallic catalysts kunanenedwa kuti ndi njira ya tandem catalysis.Makamaka, ma NP a golide amatha kupanga mpweya wambiri wa CO pafupi ndi Cu pamwamba.Kenako, mamolekyu ochuluka a CO amatha kuchepetsedwa kukhala C2+ mowa ndi Cu.

(A mpaka C) Zotsatira za aloyi.(A) Kuchuluka kwa FE kwa ethanol ndi C2H4 ndi FE chiŵerengero cha ethanol ndi ethylene pamitundu yosiyanasiyana ya Cu-Zn.(B) Kachulukidwe kakang'ono ka ethanol pamitundu yosiyanasiyana ya Cu-Zn.(A) ndi (B) adapangidwanso ndi chilolezo kuchokera ku American Chemical Society (38).(C) Kuchepetsa CO2 ndi kusintha kwa CO pa golide, mkuwa, ndi Au-Cu bimetallic system.Idasindikizidwanso ndi chilolezo chochokera ku Nature Publishing Group (96).(D mpaka L) morphology kapena kapangidwe kake.(D) Chithunzi chojambula chachitsulo choyendetsa njinga yachitsulo.(E ndi F) SEM zithunzi za 100-mkombero Cu pamaso (E) ndi pambuyo (F) prereduction pansi ECR mikhalidwe.(G) TEM ndi diffraction ya ma elekitironi yosankhidwa yati Cu(100) idawululidwa ndi (H) mphamvu yaulere ya *OCCO ndi *OCCHO mapangidwe pa Cu(100), Cu(111), ndi Cu(211) mbali.(D) mpaka (G) amapangidwanso ndi chilolezo kuchokera ku Nature Publishing Group (42).(I) Ratio ya oxygenates ndi ma hydrocarbon monga ntchito yotheka pa Cu(111), Cu(751), ndi Cu(100).(J) Manambala ogwirizanitsa a Cu(111), Cu(100), ndi Cu(751).(I) ndi (J) amapangidwanso ndi chilolezo kuchokera ku National Academy of Sciences (97).(K) Dongosolo lakusintha kuchokera ku Cu NPs kukhala mkuwa ngati cubic.Idapangidwanso ndi chilolezo kuchokera ku National Academy of Sciences (98).(L) Zithunzi za SEM zamkuwa wa nanodendritic isanafike ndi pambuyo pa ECR.Idapangidwanso ndi chilolezo chochokera ku American Chemical Society (99).

Kuwonetsedwa kosankhidwa kwa mawonekedwe a kristalo kwa ma electrocatalysts kwawonetsedwa ngati njira yothandiza komanso yowongoka kuti mukwaniritse bwino FE kuzinthu zinazake za ECR komanso njira yofunikira pakumvetsetsa kofunikira.Kaphatikizidwe kosavuta koma kowopsa ka chothandizira makristalo amodzi ndizovuta.Mouziridwa ndi njira ya galvanostatic charging-discharging (GCD) ya mabatire, gulu lathu linapanga njira yoyendetsa njinga yachitsulo (mkuyu. 6D) kuti iwonetsere mwapadera mbali ya kristalo ya Cu chothandizira (42).Pambuyo pa 100 GCD cycles, wandiweyani Cu nanocube gulu linapangidwa pa Cu zojambulazo ndi mbali (100) mbali (mkuyu 6, E mpaka G).Chothandizira chozungulira cha 100 chinapereka C2+ mowa FE woposa 30% komanso kachulukidwe ka mowa ka C2+ kopitilira 20 mA cm−2.Komabe, Cu-cycle Cu yokhala ndi chiŵerengero chochepa cha (100) inangopereka C2+ mowa FE wa ~ 10%.Kuyerekezera kwa DFT kunatsimikizira kuti Cu (100) ndi masitepe (211) anali abwino kwambiri kuti C─C igwirizane ndi Cu (111), monga momwe tawonetsera mkuyu 6H.Chothandizira chachitsanzo, filimu ya epitaxial Cu yokhala ndi mbali zosiyanasiyana zowonekera, yagwiritsidwa ntchito kuti iwonetsere malo omwe akugwira ntchito ku C2 + oxygenate kupanga (Mkuyu 6I) (97).Popeza ndizocheperako kuti CO * dimer ikhale moyandikana ndi maatomu a H * pamtunda wokhala ndi oyandikana nawo ochepa, malo ocheperako a Cu amatha kupondereza mapangidwe a ma hydrocarboni ndikupangitsa kuti C2+ oxygenate FE ikhale yabwino chifukwa ndizovuta kwambiri kuti hydrogenate. C─C yophatikizira ECR zapakati pamtunda wake (97).Mu kafukufuku wa filimu wa Cu epitaxial, olemba adatsimikizira kuti ECR pa Cu (751) mbali inawonetsa kusintha kwa oxygenate / hydrocarbon ratio.Kupititsa patsogolo kumeneku kutha kufotokozedwa ndi mawonekedwe a Cu atomu yamitundu yosiyanasiyana ya Cu ndi nambala yofananira yofananira (mkuyu 6J), pomwe atomu ya Cu idalumikizidwa, motsatana, ndi oyandikana nawo awiri, anayi, ndi asanu ndi limodzi apafupi pa Cu(751), Cu(100), ndi Cu(111) mbali.In situ morphology reconstruction yagwiritsidwanso ntchito kukonza C2+ oxygenate FE.Chothandizira chogwira cha cube ngati Cu chidapangidwa ndi Yang ndi ogwira nawo ntchito (98), omwe adawonetsa magwiridwe antchito a C─C.Mwatsatanetsatane, monodisperse Cu NPs (6.7 nm) yokhala ndi katundu wosiyanasiyana adayikidwa pakuthandizira pepala la kaboni ngati chothandizira ECR.Mwachiwonekere, kuwonjezeka kwa FE kwa C2 + oxygenates kunawonedwa ndi kuwonjezeka kwa Cu NP kutsitsa.Zinasonyezedwa kuti anali odzaza Cu NPs pansi mkulu Mumakonda zinthu anakumana mu situ morphological kusintha pa ECR, imene kyubu ngati morphologies anali potsiriza anapanga (mkuyu. 6K).Mapangidwe atsopanowa adapezeka kuti ali ndi mphamvu zambiri zamagetsi.Kusanthula kwa Tafel kunasonyeza kuti CO dimerization inali sitepe yodziwira mlingo wa C2 kupanga mankhwala, pamene n-propanol inasonyeza njira yowonekera mu dongosolo lothandizirali.Mkuwa wa nanodendritic ndi chitsanzo china chomwe chimasonyeza kufunikira kwa kayendetsedwe ka morphology kwa C2 + oxygenate kupanga (99).Mwachidule, FE yonse ya nanodendrite yamkuwa yodziwika bwino (Mkuyu 6L) ya C2 + mowa inali pafupifupi 25% pa -1.0 V motsutsana ndi RHE.Chochititsa chidwi cha n-propanol FE cha 13% chikhoza kutheka pa -0.9 V. Poganizira za ntchito yaikulu ya Cu atomu, zopangira zamkuwa nthawi zonse zimavutika ndi kuwonongeka kwa mapangidwe panthawi ya ECR, makamaka papamwamba kwambiri, zomwe zimapangitsa kuti anthu azikhala osauka. bata.Komabe, mkuwa woterewu wa nanodendritic umasonyeza kukhazikika kwa mowa, kusonyeza mowa wa FE wa ~ 24% pa maola 6.

Zolakwika zama electrocatalysts, monga malo a atomu ndi ma dopants, zikuwonetsa kuthekera kotsatsa ma ECR osagwirizana, motero, kukulitsa njira yofananira yopita ku oxygenates (29, 43, 100).Kutenga * C2H3O mwachitsanzo, yomwe ingathe kukhala yapakati pakupanga kwa ethylene ndi ethanol, Sargent ndi ogwira nawo ntchito (43) adaphunzira ntchito ya zolakwika mu core-shell Cu electrocatalyst mwatsatanetsatane.Iwo theoretically anasonyeza kuti zimene mphamvu zotchinga kwa ethylene ndi Mowa mapangidwe anali ofanana oyambirira C─C lumikiza siteji (0,5-V overpotential) (mkuyu. 7A).Mu chikhalidwe chotero, kumayambiriro mkuwa ntchito pang'ono kuonjezera mphamvu chotchinga kwa ethylene mapangidwe, koma sanasonyeze mphamvu pa Mowa m'badwo (mkuyu. 7B).Komabe, monga momwe tawonetsera mkuyu 7C, zopangira zamkuwa zomwe zili ndi ntchito komanso dopant ya sulfure yapansi panthaka zitha kukulitsa chotchinga chamagetsi panjira ya ethylene, ndikupangitsa kuti ikhale yosasangalatsa.Komabe, kusinthidwa kotereku kunawonetsa zotsatira zoyipa panjira ya ethanol.Chochitika ichi chinatsimikiziridwa moyesera.Chipolopolo chokhazikika cha Cu2S-Cu chokhala ndi malo ochulukirapo (Cu2S-Cu-V; Mkuyu 7D) adapangidwa.Chiŵerengero cha mowa kuti ethylene chinawonjezeka kuchokera 0,18 pa anabala Cu NPs kuti 0,34 pa ntchito wopanda Cu2S-Cu ndiyeno 1.21 pa Cu2S-Cu-V, ngakhale okwana FE wa C2 + mankhwala kwa catalysts onse anakhalabe ofanana (mkuyu 7E) .Kuwonetsetsa uku kunasonyeza kuti kukwezedwa kwa kusankhidwa kwa mowa kumagwirizanitsidwa ndi kuponderezedwa kwa kupanga ethylene, mogwirizana ndi zotsatira za DFT.Kuphatikiza apo, uinjiniya wopanda vuto umakhala ndi gawo lofunikira kwambiri pazothandizira zitsulo zopanda kaboni popeza zida za kaboni zoyera sizigwira ntchito ku ECR.Ma dopants monga nayitrogeni ndi boron agwiritsidwa ntchito posintha mawonekedwe amagetsi a chothandizira chochokera ku kaboni (31, 43, 100).Mwachitsanzo, filimu ya nitrogen-doped nanodiamond (NDD) pa silicon gawo lapansi idapangidwa ndi Quan et al.(29) posankha kupanga acetate kuchokera ku ECR (Mkuyu 7F).Mphamvu yoyambira ya acetate inali yochepa ngati -0.36 V motsutsana ndi RHE pogwiritsa ntchito chothandizira cha NDD, ndipo FE ya acetate inali yoposa 75% mumtundu womwe ungakhalepo kuchokera ku -0.8 mpaka -1.0 V motsutsana ndi RHE.Kuti timvetsetse chiyambi cha kusintha kochititsa chidwi kotereku, ma elekitirodi a NDD / Si okhala ndi zinthu zosiyanasiyana za nayitrogeni kapena mitundu ya nayitrogeni adakonzedwa ndikufufuzidwa (mkuyu 7G).Olembawo adatsimikiza kuti ntchito yabwino kwambiri ya NDD/Si ​​chothandizira ECR ikhoza kukhala chifukwa cha kuchuluka kwake kwa hydrogen evolution ndi N doping, pomwe mitundu ya N-sp3C inali yogwira ntchito kwambiri popanga acetate.Deta ya Electrokinetic ndi in situ infrared spectrum yavumbula kuti njira yaikulu yopangira acetate ingakhale CO2 → *CO2− → *(COO)2 → CH3COO−.Kupatula nayitrogeni, boron ndi heteroatom yofufuzidwa bwino kuti aziwongolera mawonekedwe amagetsi a nanodiamond.Komabe, boron-doped nanodiamond (BDD) imakonda kuchepetsa CO2 kukhala formaldehyde kapena formate (101).Kuphatikiza apo, Quan ndi ogwira nawo ntchito (102) adawonetsa kuti boron ndi nitrogen co-doped nanodiamond (BND) adawonetsa kulumikizana kwa ECR, komwe kumatha kuthana ndi kuchepa kwa BDD ndikusankha kupanga ethanol.BND1, BND2, ndi BND3 zothandizira zomwe zili ndi nayitrogeni zosiyanasiyana komanso milingo yofananira ya boron doping idakonzedwa.Monga momwe tawonetsera mkuyu 7H, kusankha kwapamwamba kwambiri kwa ethanol mpaka 93% kungapezeke pa chothandizira cha BND3 pa -1.0 V motsutsana ndi RHE, yomwe ili ndi doping yapamwamba kwambiri ya nayitrogeni.Kuwerengera kwamalingaliro kunawonetsa kuti njira yolumikizira C─C pa BND inali yabwino kwambiri ndi thermodynamically, pomwe atomu ya boron idalimbikitsa kugwidwa kwa CO2 ndipo nitrogen dopant idathandizira kuti hydrogenation yapakatikati kupita ethanol.Ngakhale heteroatom-doped nanodiamond amatha kusintha CO2 mu multicarbon oxygenates ndi kusankha mkulu, ECR ntchito yake ndi yochepa chifukwa cha pang'onopang'ono mlandu kutengerapo ndondomeko (pano kachulukidwe zosakwana 2 mA cm−2).Zopangidwa ndi graphene zitha kukhala yankho lotha kuthana ndi zofooka za zida za diamondi.Mwachidziwitso, malo a m'mphepete mwa pyridinic N mu graphene wosanjikiza atengedwa ngati malo omwe akugwira nawo C─C coupling (103).Izi ndichifukwa choti kupezeka kwa pyridinic N m'mphepete mwa masamba kumatha kusintha CO2 kukhala CO, yomwe imatha kuphatikizidwanso kukhala C2 + molekyulu (mkuyu 7I).Mwachitsanzo, *C2O2 yapakatikati imatha kukhazikika mu carbon-doped carbon momwe ma atomu awiri a C amamangiriridwa ku pyridinic N ndi atomu yake yoyandikana nayo C, motsatana (103).Kuneneratu kwamalingaliro kunatsimikiziridwa pogwiritsa ntchito zida za nayitrogeni-doped graphene quantum dot (NGQD) (31).Pambuyo pulverization wa nayitrogeni-doped graphene mapepala (1 kuti 3 μm) (mkuyu 7J), 1- kuti 3-nm NGQDs anapezedwa amene kachulukidwe wa pyridinic N pa m'mphepete malo chinawonjezeka ndi maulamuliro atatu kukula.Pa -0.78 V motsutsana ndi RHE, FE yochuluka ya C2 + oxygenates ikhoza kufika ku 26%.Komanso, monga momwe mkuyu. 7K, ndi tsankho panopa kachulukidwe kwa C2 + oxygenates ali pafupi 40 ma cm-2 pa -0.86 V motsutsana RHE, amene ali apamwamba kwambiri kuposa kusinthidwa nanodiamond.Poyerekeza, madontho a N-free graphene quantum ndi N-doped graphene oxide, omwe amawonetsa malo otsika kwambiri a pyridinic N, omwe amapereka H2, CO, ndi mawonekedwe.

(A to C) Gibbs free energy from *C2H3O to ethylene and ethanol for copper, copper with nocancy, and copper with copper lore and subsurface sulfure.(D) Chithunzi chojambula cha Cu2S-Cu-V chothandizira.(E) FE ya C2 + mowa ndi ethylene, komanso FE chiŵerengero cha mowa kwa alkenes.(A) mpaka (E) amapangidwanso ndi chilolezo kuchokera ku Nature Publishing Group (43).(F) Chithunzi cha SEM cha NDD.(G) Mitengo yopangira acetate ndi kupanga pa NDD yokhala ndi nayitrogeni wosiyanasiyana.pa%, atomiki%.(F) ndi (G) amapangidwanso ndi chilolezo kuchokera ku American Chemical Society (29).(H) FEs a NDD, BDD, ndi BNDs pa −1.0 V. Anapangidwanso ndi chilolezo kuchokera kwa John Wiley and Sons (102).(I) Chithunzi chojambula chamasamba omwe akugwira ntchito pa C─C kuphatikiza ma NGQD.(I) idapangidwanso ndi chilolezo chochokera ku American Chemical Society (103).(J) Chithunzi cha TEM cha NGQDs.Mipiringidzo ya sikelo, 1 nm.(K) Kachulukidwe pang'ono pakali pano pazinthu zosiyanasiyana zogwiritsa ntchito ma NGQD.(J) ndi (K) apangidwanso ndi chilolezo chochokera ku Nature Publishing Group (31).

Kupitilira ma electrocatalysts, ma elekitirodi ndi ma catalytic reactor architecture akuwonetsa njira ina yabwino yolimbikitsira magwiridwe antchito a ECR, makamaka pakupanga komanso kuwongolera mphamvu.Kusintha kwakukulu kwapangidwa pakupanga ndi kupanga makina atsopano a electroreduction kuti akwaniritse bwino kwambiri C2+ kupanga.M'chigawo chino, tikambirana za ECR electrode/reactor design mwatsatanetsatane.

Maselo amtundu wa H amagwiritsidwa ntchito kwambiri poyesa ma lab-scale, poganizira kusonkhana kwawo kosavuta, kugwira ntchito kosavuta, komanso kutsika mtengo.Ma cellwa amakhala ndi zipinda zodziyimira pawokha za cathode ndi anode zomwe zimalumikizidwa ndi nembanemba ya ion-exchange (104, 105).Kuipa kwakukulu kwa selo lamtundu wa H ndi kusungunuka kwa CO2 mu electrolyte yamadzimadzi, yomwe imakhala 0.034 M yokha pansi pa malo ozungulira, zomwe zimapangitsa kuchepetsa CO2 kuchepetsa kuchulukira kwa j <100 mA cm-2 (64).Kuphatikiza apo, zovuta zina zamkati, kuphatikiza malo ochepa a electrode pamwamba ndi mtunda waukulu wa interelectrode, zalephera kukwaniritsa zomwe zikukula pakufufuza (105, 106).Kwa C2 + kupanga zinthu, maselo amtundu wa H nthawi zambiri amasonyeza kusankhidwa kochepa pansi pa mphamvu zambiri, mwachitsanzo, 32% ya ethylene pa -0.98 V motsutsana ndi RHE (107), 13.1% ya n-propanol pa -0.9 V motsutsana ndi RHE (99), ndi 20.4% ya ethanol pa −0.46 V motsutsana ndi RHE (108), chifukwa cha kusinthika kwakukulu kwa haidrojeni.

Kuti athetse mavuto omwe ali pamwambawa, chowongolera chothamanga chinaperekedwa (15, 109).M'maselo othamanga, mpweya wa CO2 mtsinje ukhoza kugwiritsidwa ntchito mwachindunji monga chakudya cha cathode, motero kumapangitsa kuti kufalikira kwakukulu ndi kupangitse bwino (104, 110).Chithunzi 8A chikuwonetsa kamangidwe kake ka cell yotaya, pomwe nembanemba ya polymer electrolyte (PEM) idakhala ngati cholekanitsa ma elekitirodi chomwe chimayikidwa pakati pa njira ziwiri zotuluka.Chothandiziracho chimakhala chosasunthika pamagetsi a gas diffusion electrode (GDE) kuti ikhale ngati cathode electrode, momwe mpweya wa CO2 umadyetsedwa mwachindunji.Catholyte, monga 0.5 M KHCO3, imayenda mosalekeza mkati mwa wosanjikiza woonda pakati pa catalyst electrode ndi PEM.Kuphatikiza apo, mbali ya anode nthawi zambiri imazunguliridwa ndi ma electrolyte amadzimadzi kuti mpweya usinthe (43, 110).Poyerekeza ndi ma cell amtundu wa H, ma cell otaya opangidwa ndi nembanembawa amawonetsa magwiridwe antchito apamwamba kwambiri a ECR.Mwachitsanzo, Sargent ndi ogwira nawo ntchito (43) adayesa ntchito ya ECR ya Cu2S-Cu-V chothandizira pamtundu wa H-mtundu wa selo ndi selo yothamanga, monga momwe tawonetsera mu Chithunzi 8 (B mpaka E).Pogwiritsa ntchito maselo amtundu wa H, FE yochuluka ya mankhwala a C2 + inali 41% yokhala ndi chiwerengero chokwanira cha ~ 30 mA cm-2 pansi pa -0.95 V motsutsana ndi RHE.Komabe, FE ya mankhwala a C2 + inakula kufika ku 53% ndi kuchuluka kwamakono komwe kumadutsa mosavuta 400 mA cm−2 pansi -0.92 V motsutsana ndi RHE mu kayendedwe ka kayendedwe.Kuwongolera kwakukulu kotereku pogwiritsa ntchito choyatsira choyatsira kumatha kuphatikizidwa ndi kuwonjezereka kwa CO2 kufalikira ndi kuponderezedwa kwa mbali, makamaka zochokera kumagetsi amagetsi amagetsi apatatu.

(A) Chithunzi cha cholumikizira cha electrolyzer chokhala ndi mawonekedwe owoneka bwino a electrode-electrolyte interface.(A) idapangidwanso ndi chilolezo chochokera kwa John Wiley ndi Ana (30).(B mpaka E) Kuyerekeza kwa magwiridwe antchito a ECR pogwiritsa ntchito ma cell amtundu wa H ndi cell cell.(B) mpaka (E) amapangidwanso ndi chilolezo chochokera ku Nature Publishing Group (43).(F mpaka H) Ma electrolyte osiyanasiyana omwe amagwiritsidwa ntchito m'maselo othamanga ndi machitidwe a ECR.(F) mpaka (H) amapangidwanso ndi chilolezo kuchokera kwa John Wiley ndi Ana (30).(I mpaka K) Kapangidwe ndi kukhazikika kwa ma elekitirodi otulutsa mpweya wa polima.(I) mpaka (K) amapangidwanso ndi chilolezo kuchokera ku AAAS (33).

Selo la zero gap ndi gulu lina lomwe likutuluka la ma electrolyzers, omwe amachotsanso njira zoyendera m'maselo oyenda ndikukanikizira maelekitirodi awiri pamodzi ndi nembanemba yosinthira ion pakati.Kukonzekera kumeneku kungathe kuchepetsa kusuntha kwa anthu ambiri ndi kukana kusamutsa ma elekitironi motero kumapangitsa kuti mphamvu zowonjezera zikhale zotheka pogwiritsira ntchito (110).Zomwe zimaperekedwa ku cathode zimatha kukhala CO2-saturated catholyte kapena mtsinje wa CO2 wonyowa.Mpweya wamadzi kapena ma electrolyte amadzimadzi amaperekedwa ku anode kuti atulutse pulotoni kuti alipire mtengo wa mitundu yochepetsera ya CO2 (111).Gutiérrez-Guerra et al.(109) idawunika momwe Cu-AC hybrid chothandizira mu cell ya zero gap imagwira ntchito ndipo inanena kuti acetaldehyde ndiye chinthu chachikulu chomwe chimakhala ndi kusankha kwakukulu kwa 60%.Ubwino winanso wa chipangizochi, ndikosavuta kukakamiza kuthamanga kwa reactant ndikuwonjezera kwambiri CO2 m'dera lanu, zomwe zimapangitsa kuti kachulukidwe kakakulu komanso kuchuluka kwamachitidwe (110).Komabe, kuchuluka kwa ma ion kusinthana m'maselo a zero kumapangitsa kuti catholyte ikhale acidity, kusinthira zomwe zimachitika ku H2 kusinthika m'malo mwa kuchepetsa CO2 (112).Kuti athane ndi vutoli, Zhou ndi ogwira nawo ntchito (112, 113) adayika chotchinga chokhala ndi ma electrolyte amadzi ozungulira pakati pa cathode ndi nembanemba kuti asunge pH yoyenera pafupi ndi cathode kuti achepetse CO2.Ngakhale kuti zinthu zosiyanasiyana za C2 + zinapezeka pamaziko a maselo a zero, kuphatikizapo acetone, ethanol, ndi n-propanol, FEs akadali otsika kwambiri.Maphunziro ambiri omwe amanenedwa nthawi zonse amayang'ana kwambiri zinthu za C1 zomwe zimaphatikizapo kusamutsidwa kwa ma proton ndi ma elekitironi pang'ono panthawi yochepetsera.Chifukwa chake, kuthekera kwa zero gap cell pazinthu za C2+ zikadali mkangano (110).

Komanso, ma microfluidic electrolytic cell (MECs) ndi mtundu wa kasinthidwe kokongola ka electrolyzer kopangidwa ndi Kenis ndi ogwira nawo ntchito (39, 114).Mu chipangizo ichi, nembanemba m`malo ndi danga woonda (<1 mm mu makulidwe) wodzazidwa ndi ikuyenda electrolyte mtsinje kulekanitsa anode ndi cathode.Mamolekyu a CO2 amatha kufalikira mwachangu mu mawonekedwe a electrode-electrolyte pafupi ndi cathode, ndipo ma GDE awiri okhazikika amasunthidwa ndi ma electrolyte oyenda.Poyerekeza ndi ma cell otumphukira a nembanemba, ma MEC samangopewa kukwera mtengo kwa nembanemba komanso amachepetsa kasamalidwe ka madzi, zomwe makamaka zimatanthawuza kusefukira kwa anode ndi kusefukira kwa ma cathode akamagwiritsidwa ntchito pakachulukidwe kakakulu chifukwa cha kukokera kwa mamolekyu amadzi ndi osmotic. mayendedwe a proton kuchokera ku anode kupita ku cathode kudutsa nembanemba (115).Monga tikudziwira, ngakhale zowoneka bwino ndi zopambana, kafukufuku wocheperako adapeza zinthu za C2+ m'ma MEC oyambilira.Izi mwina chifukwa cha "kuyandama" zotsatira kuti mapulotoni opangidwa mu anode mosavuta chatsanulidwa kuchokera cathode pafupi kapena kutsukidwa ndi ukuyenda electrolyte, m'malo mochita nawo angapo pulotoni chofunika C2 + mapangidwe anachita.Zongopekazo zitha kutsimikiziridwa ndi chitsanzo chotsatirachi.Mu 2016, Kenis ndi ogwira nawo ntchito (31) adanena za kuchepetsa bwino kwa CO2 ku C2 + mankhwala pa MEC yosinthidwa komanso yokhala ndi nembanemba, momwe NGQDs imatha kuchepetsa mamolekyu a CO2 ku C2 + ndi 55% FE (31% ya ethylene, 14% kwa ethanol, 6% kwa acetate, ndi 4% kwa n-propanol) pa mphamvu yogwiritsira ntchito -0.75 V motsutsana ndi RHE mu 1 M KOH yankho.Ndikofunikira kunena kuti chilengedwe cha electrolyte chingakhudzenso kusankha kwazinthu.Mwachitsanzo, Jiao ndi ogwira nawo ntchito (30) adapanga chothandizira cha Cu nanoporous ndikuyesa ntchito yake ya ECR pogwiritsa ntchito ma electrolyte osiyanasiyana (KHCO3, KOH, K2SO4, ndi KCl) mu MEC yochokera ku membrane.Iwo adawulula kuti kuchepa kwa CO2 mu alkaline electrolyte (KOH) kumasonyeza kusankhidwa kwapamwamba kwambiri kwa C2 + ndi kachulukidwe kamakono, monga momwe tawonetsera mkuyu 8 (F ndi G).Pa −0.67 V motsutsana ndi RHE mu 1 M KOH electrolyte, FE yopezedwa ya C2+ imafika mpaka 62% ndi kachulukidwe kakang'ono ka 653 mA cm−2, yomwe ili m'gulu la kachulukidwe kakang'ono kwambiri komwe kadanenedwapo pakuchepetsa kwa electrochemical CO2. kuzinthu za C2+.Ethylene (38.6%), ethanol (16.6%), ndi n-propanol (4.5%) ndizo zikuluzikulu za C2 + zomwe zimakhala ndi acetate pang'ono.Ananenanso kuti pali kugwirizana kwakukulu pakati pa pH yowerengedwa pamwamba ndi FE kwa mankhwala a C2 +: Kukwera pamwamba pa pH, kuchulukira kwamakono ndi C2 + zokolola, monga momwe tawonetsera mkuyu 8H.Kuwerengera kwamalingaliro kunapangitsa kuti ma OH− ma ion omwe ali pafupi ndi pamwamba athandizire kwambiri kulumikizana kwa C─C (31).

Kuphatikiza pa kasinthidwe ka electrolyzer, ma electrolyte omwe amagwiritsidwa ntchito m'ma electrolyzer osiyanasiyana amathanso kusintha kwambiri zinthu zomaliza za ECR.Monga tafotokozera pamwambapa, mayankho a alkaline a KOH nthawi zonse amagwiritsidwa ntchito m'maselo oyenda omwe amagwira bwino ntchito m'malo mwamaselo amtundu wa H.Zimanenedwa kuti ma electrolyte a KOH amatha kupangitsa kuti ma electrolyte achuluke, amachepetsa kukana kwa ohmic pakati pa zokutira zopyapyala zama electrolyte pa chothandizira ndi ma electrolyte ambiri, ndikuchepetsanso kuchuluka kofunikira pakupanga C2+ (31).Zotsatira za DFT zimatsimikiziranso kuti kukhalapo kwa ma OH-ion kumatha kutsitsa chotchinga cha CO dimerization, motero kukulitsa mapangidwe a C2 + ndikupondereza mpikisano kuchokera ku C1 ndi H2 mapangidwe (30, 33).Komabe, alkaline KOH sakanatha kugwiritsidwa ntchito ngati electrolyte m'maselo amtundu wa H.Izi ndichifukwa choti mitsinje ya CO2 idzachitapo kanthu mwachangu ndi mayankho a KOH ndipo pomaliza pake ipanga njira ya bicarbonate yokhala ndi pH yopanda ndale m'maselo amtundu wa H (30).M'maselo oyenda, komabe, CO2 ikafalikira kudzera mu GDE, mamolekyu a CO2 adzadyedwa pagawo lamalire atatu (CO2-catalyst-electrolyte) kuti apange zinthu zochepetsedwa nthawi yomweyo.Kupatula apo, kusakwanira bwino kwa electrolyte kumatha kuchulukitsa pH mozungulira ma elekitirodi m'makonzedwe okhazikika a electrolyzer, pomwe ma elekitirodi oyenda amatsitsimutsa pamwamba ndikuchepetsa kusinthasintha kwa pH mu electrolyte (33, 116).

Monga tanenera kale kuti ECR ndiyomwe imayendetsedwa ndi kufalikira, kupanikizika kwakukulu kungathenso kupititsa patsogolo kuchulukana ndi mawonekedwe a CO2.Ma reactors othamanga kwambiri ndi ofanana ndi autoclave yachitsulo chosapanga dzimbiri, momwe mpweya wothamanga kwambiri wa CO2 (mpaka 60 atm) ukhoza kulowetsedwa m'selo, zomwe zimapangitsa kuti FE iwonjezeke komanso kachulukidwe ka C2+ (117) , 118).Sakata ndi ogwira nawo ntchito (119) adawonetsa kuti kachulukidwe kakali pano atha kukhala 163 mA cm−2 pansi pa 30 atm pa Cu electrode yokhala ndi ethylene ngati chinthu chachikulu.Zothandizira zitsulo zambiri (mwachitsanzo, Fe, Co, ndi Ni), popanda ntchito yopangira C2 + pa kupanikizika kozungulira, zingathe kuchepetsa CO2 ku ethylene, ethane, propane, ndi zinthu zina zapamwamba za C2 + pazovuta zapamwamba.Zasonyezedwa kuti kusankha kwa zinthu kumadalira kwambiri mphamvu ya CO2 m'njira yosinthira kupezeka kwa CO2 pamtunda wa electrode (117, 120).Zogulitsa zazikulu zochepetsedwa zimasinthidwa kuchokera ku H2 kupita ku ma hydrocarbons (C2 + ikuphatikizidwa) ndipo pamapeto pake kupita ku CO/HCOOH ndi kuchuluka kwa CO2 kukakamiza.Makamaka, kupanikizika kwa CO2 kuyenera kuyang'aniridwa mosamala chifukwa kupanikizika kwambiri kapena kutsika kwa CO2 kungapangitse kuchuluka kwa CO2 kapena kuchepa kwa CO2, zomwe zimakonda kupangidwa kwa CO/HCOOH kapena H2.Kuchuluka kogwirizana kwa CO ndi kachulukidwe komwe kamapangidwa pamtunda wa electrode kumatha kuthandizira kugwirizanitsa kwa C─C ndikukulitsa kusankha kwa C2+ (119).

Kupanga ma elekitirodi atsopano okhala ndi zida zapamwamba ndi njira ina yofunika kupititsa patsogolo kupanga kwa C2+.Kumayambiriro koyambirira, maelekitirodi omwe amagwira ntchito ndi zolembera zachitsulo zopanda mpweya ndipo amavutika ndi kusamutsa kwaulesi (26, 105).Zotsatira zake, GDE idapangidwa kuti ichepetse kusayenda bwino kwa maselo popereka njira za hydrophobic zomwe zimathandizira kufalikira kwa CO2 kupita ku tinthu tating'onoting'ono (121).GDE wamba nthawi zambiri amakhala ndi chothandizira wosanjikiza (CL) ndi gasi diffusion wosanjikiza (GDL), monga taonera m'munsi mwa Mkuyu. 8A (30, 33).Mawonekedwe a gasi-madzi-catalyst opangidwa mu GDE ndi ofunikira kuti ma cell agwire bwino ntchito.GDL yosonkhanitsidwa ndi zida za porous (nthawi zambiri pepala la kaboni) imatha kupereka njira zambiri za CO2 ndikuwonetsetsa kuti ma electrolyte amafalikira mwachangu.Imagwiranso ntchito ngati njira yochepetsera kukana kwa ma protoni, ma elekitironi, ndi zinthu zochepetsera kuchokera ku CL kupita ku electrolyte (121).Kuponya, kuponyera mpweya, ndi electrodeposition ndi matekinoloje omwe amagwiritsidwa ntchito pokonzekera ma GDE (122).Zothandizira zomwe zasonkhanitsidwa ndi ma GDE zafufuzidwa mozama mu CO2 electroreduction to C2+ product.Makamaka, ma cell otuluka omwe tawatchulawa omwe akuchita bwino onse amaphatikizidwa ndi ma GDE.Kumayambiriro kwa 1990, Sammells ndi ogwira nawo ntchito (123) adanena kuti Cu-coated GDEs adapeza FE yapamwamba ya 53% ya ethylene yokhala ndi mphamvu zambiri za 667 mA cm−2.Kupititsa patsogolo kusankhidwa kwa ethylene ndi ethanol ndizovuta kwambiri zomwe nthawi zonse zimapangidwira pa Cu-based catalysts chifukwa cha njira zawo zofananira zamakanika.Komanso, ndikofunika kunena kuti zokolola zapamwamba ndi kusankha kwa ethylene poyerekeza ndi ethanol zawonedwa pa Cu-based GDE (25, 36).Gewirth ndi ogwira nawo ntchito (36) adawonetsa FE yabwino kwambiri ya 60% ya ethylene ndi FE yoponderezedwa ya ethanol ya 25% pa electrodeposited Cu-Ag GDE, pamene kachulukidwe kameneka kanafika ~ 300 mA cm−2 pa -0.7 V motsutsana ndi RHE.Ndi ntchito yosowa yomwe idakwaniritsa kusankha kwakukulu pamlingo waukulu wamakono.Kupeza uku kukuwonetsa kuti ma elekitirodi ophatikizidwa ndi GDE amapereka njira yodalirika yosinthira njira zomwe zimachitikira, momwe kusankhidwa kwa zinthu zochepetsedwa kumatha kupezeka pakachulukidwe kwambiri.

Kukhazikika kwa ma GDE kulinso vuto lalikulu lomwe liyenera kuthetsedwa chifukwa kugwira ntchito kwanthawi yayitali ndikofunikira kuti muzindikire kugwiritsa ntchito bwino kwa ma cell otaya.Ngakhale kuti CO2-to-C2 + yachita bwino kwambiri ndi ma GDE, kukhazikikaku kudakali koyipa chifukwa cha makina ofooka a chothandizira, GDL, ndi zigawo zomangira (77, 124).Mpweya wa carbon wa GDL ukhoza kusintha kuchoka ku hydrophobic kupita ku hydrophilic panthawi ya electrochemical reaction chifukwa cha makutidwe ndi okosijeni omwe anachitika pamalo okwera kwambiri, omwe amatsogolera kusefukira kwa GDL ndi kutsekereza CO2 diffusion pathways (33).Pofuna kuthetsa vutoli, ofufuza anaphatikiza hydrophobic scaffold ya polytetrafluoroethylene (PTFE) mu GDEs.Poyerekeza ndi hydrophilic Nafion, hydrophobic PTFE wosanjikiza imapangitsa kukhazikika kwanthawi yayitali (33).Sargent ndi ogwira nawo ntchito (33) anasonkhanitsa Cu chothandizira pakati pa olekanitsidwa PTFE ndi carbon NPs, imene hydrophobic PTFE wosanjikiza akhoza immobilize NPs ndi graphite zigawo, motero kumanga khola electrode mawonekedwe (Mkuyu 8, I ndi J).Zotsatira zake, FE yopangira ethylene idakulitsidwa mpaka 70% mu njira ya 7 M KOH pamakachulukidwe apano a 75 mpaka 100 mA cm−2.Kutalika kwa moyo wa riyakitala yothamangayi kunapitilizidwa ku maola oposa 150 ndi kutayika kosawerengeka mu ethylene selectivity, yomwe ndi nthawi ya 300 kuposa GDEs yachikhalidwe, monga momwe tawonetsera mkuyu 8K.Mapangidwe a sangweji otere awonetsedwa kuti ndiabwino kwambiri a GDE.Mwachitsanzo, Cui ndi ogwira nawo ntchito (124) adapanga mawonekedwe a trilayer okhala ndi ma electrode osanjikiza odulidwa ndi mafilimu awiri a hydrophobic nanoporous polyethylene.Zigawo zakunja za hydrophobic zimatha kuchepetsa kuthamanga kwa electrolyte kuchokera ku njira yochuluka, zomwe zimatsogolera ku khola, pH yapamwamba yapafupi kuzungulira electrode yogwira ntchito.Kukhathamiritsa kwa danga la interlayer, komwe kumatha kupititsa patsogolo kayendedwe ka CO2 ndi kutsatsa, ndikofunikiranso pamapangidwe otere (124).Posachedwapa, ma carbon nanotubes aphatikizidwanso mu GDEs chifukwa cha porosity yawo yayikulu, ma conductivity abwino, ndi hydrophobicity, zomwe zimatha kuwongolera ma elekitironi ndi mayendedwe ambiri (77).

Ngakhale zosangalatsa zikupita patsogolo pa ECR, njira zotsika mtengo, zazikulu zopangira C2+ sizipezeka kawirikawiri (125).Pakadali pano, zovuta ndi mwayi zimagwirizana kuti timvetsetse momwe ECR imagwirira ntchito ndikugulitsa ukadaulo wolonjezawu.

Monga njira yabwino kwambiri yotsekera mpweya wa kaboni ndikusunga mphamvu zongowonjezereka, monga mphepo ndi dzuwa, kupita patsogolo kwakukulu kwachitika kuti akwaniritse kusintha kwa CO2 m'zaka makumi angapo zapitazi.Ngakhale kumvetsetsa kwa njira zomwe zimagwirizanitsidwa ndi ECR kwafika patali kuyambira masiku ake oyambirira (126), kulumikizana kwa C─C kudzera pa ECR kuzinthu za C2+ sikunali kokonzeka kugwiritsidwa ntchito.Mukuwunikaku, tayang'ana mwatsatanetsatane njira zomwe zilipo zomwe zingalimbikitse kusankha ndi kupanga kwazinthu za C2 + kudzera pa ECR, kuphatikiza kukonza kwabwino kothandizira, zotsatira za electrolyte, mikhalidwe ya electrochemical, ndi kapangidwe ka electrochemical electrode/reactor.

Ngakhale kuyesayesa konse komwe kukuchitika mu ECR, pali zovuta zambiri ndi zoyambitsa zamakono ndi dongosolo la ECR lomwe liyenera kuyankhidwa musanayambe kugulitsa ECR.Choyamba, monga chothandizira kwambiri kuti athe kuzindikira kulumikizana koyenera kwa C─C, Cu imakhala ndi zovuta zokhazikika, makamaka mu ma electrolyte amadzimadzi, ndipo samatha kukhala ndi moyo kwa maola 100 chifukwa chakuyenda kwawo kwa atomu yayikulu, kuphatikizika kwa tinthu, komanso kuwonongeka kwa kapangidwe kake pansi pa mikhalidwe ya ECR.Choncho, momwe mungakwaniritsire kukhazikika kwa nthawi yayitali pogwiritsa ntchito Cu-based catalyst ndizovuta.Kukhazikitsa chothandizira chokhazikitsidwa ndi Cu pa chithandizo chapadera ndi kulumikizana mwamphamvu kungakhale njira yodalirika yotetezera kapangidwe kameneka kakupangitsa kuti pakhale moyo wautali.Komanso, ntchito polima nembanemba electrolyte m'malo njira amadzimadzi pa ECR mwina patsogolo kukhazikika kwa Cu ofotokoza chothandizira.Kuonjezera apo, kuchokera kuzinthu zowonongeka, njira zowonetseratu mu situ / mu operando ndi njira zowonongeka ziyenera kugwiritsidwanso ntchito poyang'anira ndi kumvetsetsa kuwonongeka kwa ntchito zowonongeka, motero, kupondereza kuwonongeka ndi poizoni wa chothandizira kumagulu otsika kwambiri.Nkhani ina yofunika kwambiri ya ECR catalysts yomwe iyenera kuyankhidwa ndikupangitsa kuti protocol ya kaphatikizidwe ikhale yotheka pakupanga kwakukulu.Pachifukwa ichi, kuwongolera njira zopangira pogwiritsa ntchito zakudya zomwe zimapezeka kwambiri ndizofunikira.

Chachiwiri, kwaiye C2+ okosijeni kuchokera ECR nthawi zambiri wothira solutes (mwachitsanzo, KHCO3 ndi KOH) mu electrolyte chikhalidwe H- kapena otaya-selo reactors, amene Komabe, amafuna owonjezera kulekana ndi ndende njira kuti achire koyera madzi mafuta njira mu. ntchito zothandiza.Nthawi yomweyo, ma C2 + ma hydrocarbon osinthika amasakanikirananso ndi H2 ndi CO2 yotsalira.Chifukwa chake, njira yolekanitsa yokwera mtengo ndiyofunikira paukadaulo wamakono wa ECR, womwe umalepheretsanso ECR kugwiritsa ntchito bwino.Choncho, mmene mwachindunji ndi mosalekeza kupanga koyera madzi mafuta njira ndi koyera gasi hydrocarbons, makamaka ndi woipa kwambiri mankhwala, ndi zofunika kwambiri pa ntchito zothandiza ECR.Chifukwa chake timaneneratu kukwera kwachindunji kwa zinthu zoyera kudzera pa ECR posachedwa, zomwe zitha kutenga ukadaulo wa ECR kuyandikira msika (127).

Chachitatu, pamene mapangidwe a C─O ndi C─H, monga ethanol, acetic acid, ndi ethylene, mu teknoloji ya ECR yaphunziridwa kwambiri, kufufuza kwa mitundu ina ya mankhwala ndikofunikanso kwa teknoloji ya ECR ndikuwonetsa chidwi chachuma.Mwachitsanzo, posachedwapa, Han ndi ogwira nawo ntchito (128) adanena za kupanga 2-bromoethnol ndi ECR.Mapangidwe a in situ a C─Br bond amasintha mankhwala kuchokera ku ethanol kupita ku 2-bromoethnol, yomwe ndi yofunika kwambiri pakupanga mankhwala ndi mankhwala ndipo imasonyeza mtengo wowonjezera.Chifukwa chake, kupitilira zomwe zaphunziridwa bwino za C2+, timakhulupirira kuti kutsata zinthu zina zomwe sizimawunikidwa kawirikawiri monga oxalic acid (129) komanso kaphatikizidwe ka mamolekyu ovuta kwambiri a C2+ monga ma cyclic compounds ndi njira ina yodalirika yopangira kafukufuku wamtsogolo wa ECR.

Pomaliza, ma elekitirodi atsopano ndi ma reactor monga GDE osalowa madzi, ma cell amadzimadzi, ndi PEM cell akuyenera kuvomerezedwa kuti apititse patsogolo kuchuluka kwa kupanga kwa ECR kukhala mulingo wamalonda (> 200 mA cm−2).Komabe, kusiyana kwakukulu muzochitika za electrocatalytic kumawonedwa nthawi zonse pamene ma electrocatalysts amagwiritsidwa ntchito poyesa maselo onse.Chifukwa chake, kafukufuku wowonjezereka akuyenera kuchitidwa kuti achepetse kusiyana pakati pa maphunziro a theka la cell ndi kugwiritsa ntchito zida zonse kuti abweretse ECR kuchokera ku mayeso a labu kuti agwiritse ntchito.

Mwachidule, kuchepetsa kwa electrochemical CO2 kumapereka mwayi wabwino kwa ife kuthana ndi vuto la chilengedwe kuchokera ku mpweya wowonjezera kutentha wopangidwa ndi zochita za anthu.Ikuwonetsanso kuthekera kokwaniritsa mafuta oyeretsera ndi mankhwala pogwiritsa ntchito mphamvu zongowonjezwdwa.Ngakhale zovuta zambiri zidakalipo paukadaulo wa ECR pakadali pano, makamaka pakuphatikiza kwa C─C, akukhulupirira kuti pakupitilira kafukufuku ndi chitukuko pazothandizira zonse komanso kukhathamiritsa kwa ma cell, malingaliro a dziko lenileni la CO2 electrolysis yamafuta oyera. ndipo mankhwala adzakwaniritsidwa posachedwapa.

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© 2020 American Association for the Advancement of Science.Maumwini onse ndi otetezedwa.AAAS ndi mnzake wa HINARI, AGORA, OARE, CHORUS, CLOCKSS, CrossRef ndi COUNTER.Science Advances ISSN 2375-2548.