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Electrosynthesis nke adipic acid (ihe na-ebute naịlọn 66) site na mmanụ CA (ngwakọta nke cyclohexanone na cyclohexanol) bụ atụmatụ na-adịgide adịgide nke nwere ike dochie ụzọ ọdịnala nke chọrọ ọnọdụ siri ike. Agbanyeghị, obere njupụta ugbu a na mmeghachi omume evolushọn oxygen na-asọmpi na-ebelata ngwa ọrụ ya nke ukwuu. N'ọrụ a, anyị na-agbanwe nickel double hydroxide na vanadium iji mee ka njupụta ugbu a dịkwuo mma ma nọgide na-enwe arụmọrụ faradaic dị elu (>80%) n'ofe oke nwere ike (1.5–1.9 V vs. hydrogen electrode a na-agbanwe agbanwe). Ọmụmụ nnwale na tiori kpughere ọrụ abụọ dị mkpa nke mgbanwe V, gụnyere nhazi ngwa ngwa nke catalyst na mmịpụta cyclohexanone ka mma. Dịka ihe akaebe nke echiche, anyị wuru nzukọ membrane-electrode nke mepụtara adipic acid nwere arụmọrụ faradaic dị elu (82%) na mmepụta (1536 μmol cm-2 h-1) na njupụta ugbu a dị mkpa na ụlọ ọrụ mmepụta ihe (300 mA cm-2), ebe ọ na-enweta nkwụsi ike >50 h. Ọrụ a na-egosi ihe na-akpali akpali nke ọma maka electrosynthesis nke adipic acid nwere nnukwu mmepụta na ikike ụlọ ọrụ mmepụta ihe.
Adipic acid (AA) bụ otu n'ime asịd aliphatic dicarboxylic kachasị mkpa, a na-ejikwa ya eme ihe karịsịa na mmepụta nke naịlọn 66 na polyamides ma ọ bụ polymers ndị ọzọ1. N'ụlọ ọrụ mmepụta ihe, a na-emepụta AA site na iji oxidizing ngwakọta nke cyclohexanol na cyclohexanone (ya bụ, mmanụ AA) site na iji 50–60 vol% nitric acid dị ka ihe na-eme ka oxidizing. Usoro a nwere nchegbu gburugburu ebe obibi metụtara mwepụta nke nitric acid na nitrogen oxides (N2O na NOx) dị ka gas griinhaus2,3. Ọ bụ ezie na enwere ike iji H2O2 dị ka ihe ọzọ na-eme ka oxidizing akwụkwọ ndụ akwụkwọ ndụ, ọnụ ahịa dị elu na ọnọdụ njikọta siri ike ya na-eme ka o sie ike itinye ya n'ọrụ, a chọrọkwa usoro dị ọnụ ala ma na-adịgide adịgide4,5,6.
N'ime afọ iri gara aga, ụzọ ndị ọkà mmụta sayensị si emepụta kemịkalụ na mmanụ ọkụ eletrik adọtala mmasị dị ukwuu n'ihi uru ha nwere iji ike mmeghari ohuru na ịrụ ọrụ n'okpuru ọnọdụ dị nro (dịka ọmụmaatụ, okpomọkụ ụlọ na nrụgide gburugburu)7,8,9,10. N'akụkụ a, mmepe nke mgbanwe electrocatalytic nke mmanụ KA ka ọ bụrụ AA dị oke mkpa iji nweta uru ndị a dị n'elu yana iwepụ ojiji nke nitric acid na nitrous oxide e nwetara na mmepụta nkịtị (Foto 1a). Petrosyan et al. rụrụ ọrụ mbụ, bụ ndị kọrọ mmeghachi omume oxidation electrocatalytic nke cyclohexanone (COR; cyclohexanone ma ọ bụ cyclohexanol ka a na-amụkarị dị ka ihe na-anọchite anya mmanụ KA) na nickel oxyhydroxide (NiOOH), mana enwetara obere njupụta ugbu a (6 mA cm-2) na mmepụta AA dị oke (52%)11,12. Kemgbe ahụ, enweela ọganihu dị ukwuu na mmepe nke ihe na-akpali akpali dabere na nickel iji mee ka ọrụ COR ka mma. Dịka ọmụmaatụ, e mepụtara ihe na-akpali nickel hydroxide (Cu-Ni(OH)2) nke e ji ọla kọpa mee iji kwalite nkewa Cα–Cβ na cyclohexanol13. Anyị kọrọ na nso nso a na ihe na-akpali Ni(OH)2 nke e ji sodium dodecyl sulfonate (SDS) gbanwee iji mepụta gburugburu ebe obibi hydrophobic nke na-eme ka cyclohexanone14 baa ọgaranya.
a Ihe ịma aka nke mmepụta AA site na electrooxidation nke mmanụ KA. b Ntụnyere nke electrocatalytic COR nke ihe mkpali dabere na Ni akọwara na mbụ na ihe mkpali anyị na sistemụ electrode atọ na sistemụ batrị mmiri11,13,14,16,26. E nyere ozi zuru ezu gbasara paramita mmeghachi omume na arụmọrụ mmeghachi omume na Tebụl Mgbakwunye 1 na 2. c Arụmọrụ Catalytic nke ihe mkpali NiV-LDH-NS anyị maka COR na ihe nrụpụta H-cell na MEA, nke na-arụ ọrụ n'ofe oke nwere ike.
Ọ bụ ezie na ụzọ ndị a dị n'elu mere ka ọrụ COR ka mma, ihe ndị na-akpali akpali nke dabere na Ni gosiri arụmọrụ AA Faraday dị elu (>80%) naanị na obere ikike, nke na-adịkarị ala karịa 1.6 V ma e jiri ya tụnyere electrode hydrogen a na-agbanwe agbanwe (RHE, nke a kpọrọ VRHE). Ya mere, njupụta nke akụkụ ugbu a akọpụtara (ya bụ, njupụta ugbu a mụbara site na FE) nke AA na-adịkarị ala karịa 60 mA cm−2 (Foto 1b na Tebụl Mgbakwunye 1). Njupụta ugbu a dị ala karịa ihe achọrọ maka ụlọ ọrụ mmepụta ihe (>200 mA cm−2)15, nke na-egbochi teknụzụ electrocatalytic maka njikọ AA dị elu (Foto 1a; elu). Iji mee ka njupụta ugbu a dịkwuo mma, enwere ike itinye ikike dị mma karịa (maka sistemụ electrode atọ) ma ọ bụ voltaji sel dị elu (maka sistemụ electrode abụọ), nke bụ ụzọ dị mfe maka ọtụtụ mgbanwe electrocatalytic, ọkachasị mmeghachi omume evolushọn oxygen (OER). Agbanyeghị, maka COR nwere ike anodic dị elu, OER nwere ike ịghọ onye asọmpi dị ukwuu n'ibelata FE nke AA, si otú a belata arụmọrụ ike (Foto 1a; ala). Dịka ọmụmaatụ, na-enyocha ọganihu gara aga (Foto 1b na Tebụl Mgbakwunye 1), anyị nwere nkụda mmụọ ịchọpụta na FE nke AA na Ni(OH)2 nke SDS gbanwere belatara site na 93% ruo 76% na ịbawanye ikike etinyere site na 1.5 VRHE ruo 1.7 VRHE14, ebe FE nke AA na CuxNi1-x(OH)2/CF belatara site na 93% ruo 69% na-abawanye ikike site na 1.52 VRHE ruo 1.62 VRHE16. Ya mere, njupụta nke AA nke akụkụ ugbu a akọpụtara anaghị abawanye n'ụzọ nhata na ikike dị elu, nke na-egbochi mmezi nke arụmọrụ AA, na-ekwu maka oke oriri ike n'ihi obere FE nke AA. Na mgbakwunye na ihe ndị na-eme ka nickel dị, ihe ndị na-eme ka cobalt dị na coal egosikwala ọrụ catalytic na COR17,18,19. Agbanyeghị, arụmọrụ ha na-ebelata na ikike dị elu, ma e jiri ya tụnyere ihe ndị na-eme ka Ni dị irè, ha nwere oke ike karịa na ngwa ụlọ ọrụ mmepụta ihe, dịka mmụba ọnụahịa na obere ngwa ahịa. Ya mere, ọ dị mma ịmepụta ihe ndị na-eme ka Ni dị irè nwere njupụta ugbu a dị elu na FE na COR iji mee ka ọ baa uru inweta nnukwu mmepụta AA.
N'ọrụ a, anyị na-akọ akụkọ nanosheets hydroxide abụọ nke vanadium (V) gbanwere na nickel (NiV-LDH-NS) dị ka electrocatalysts dị irè maka mmepụta AA site na COR, nke na-arụ ọrụ n'ofe oke ike nwere OER a kpagburu nke ukwuu, na-enweta nnukwu FE na njupụta ugbu a na ma mkpụrụ ndụ H na mgbakọ electrode membrane (MEAs; Foto 1 b). Anyị na-egosi na arụmọrụ oxidation acetylene karịa ihe na-eme ka Ni(OH)2 nanosheet catalyst (Ni(OH)2-NS) na-ebelata, dịka a tụrụ anya ya, na ikike dị elu, site na 80% na 1.5 VRHE ruo 42% na 1.9 VRHE. N'ụzọ dị iche, mgbe agbanwere Ni(OH)2 na V, NiV-LDH-NS gosipụtara njupụta ugbu a dị elu na ikike enyere, nke ka mkpa, nọgidere na-enwe FE dị elu n'ofe oke ike. Dịka ọmụmaatụ, na 1.9 VRHE, o gosiri njupụta ugbu a nke 170 mA cm−2 na FE nke 83%, nke bụ ihe na-akwalite COR na sistemụ electrode atọ (Foto 1c na Tebụl Mgbakwunye 1). Data nnwale na nke echiche na-egosi na mgbanwe V na-akwalite mbelata kinetics site na Ni(OH)2 gaa na Ni oxyhydroxides dị elu (Ni3+xOOH1-x), nke na-eje ozi dị ka usoro na-arụ ọrụ maka COR. Ọzọkwa, mgbanwe V mere ka adsorption nke cyclohexanone dịkwuo mma na elu catalyst, nke rụrụ ọrụ dị mkpa n'igbochi OER na ikike anodic dị elu. Iji gosipụta ike nke NiV-LDH-NS na ọnọdụ dị adị karịa, anyị mepụtara ihe na-eme MEA flow reactor ma gosi FE nke AA (82%) na njupụta ugbu a dị mkpa maka ụlọ ọrụ mmepụta ihe (300 mA cm−2), nke dị elu karịa nsonaazụ anyị gara aga na ihe na-eme ka membrane flow reactor (Foto 1b na Tebụl Mgbakwunye 2). Mkpụrụ kwekọrọ na AA (1536 μmol cm−2 h−1) dị elu karịa nke e nwetara site na usoro ihe na-eme ka okpomọkụ dị ọkụ (<30 mmol gcatalyst−1 h−1)4. Ọzọkwa, ihe na-eme ka ọ dị ọkụ gosipụtara ezigbo nkwụsi ike mgbe ọ na-eji MEA, na-ejigide FE >80% AA maka awa 60 na 200 mA cm−2 na FE >70% AA maka awa 58 na 300 mA cm−2. N'ikpeazụ, ọmụmụ ihe mbụ (FEA) gosipụtara uru dị na atụmatụ electrocatalytic maka mmepụta AA.
Dịka akwụkwọ ndị gara aga si kwuo, Ni(OH)2 bụ ihe na-akpali akpali nke na-egosi ọrụ dị mma maka COR, ya mere e ji usoro coprecipitation mepụta Ni(OH)2-NS13,14 maka oge mbụ. Ihe nlele ndị ahụ gosiri nhazi β-Ni(OH)2, nke X-ray diffraction (XRD; Fig. 2a) kwadoro, na nanosheets ultra-thin (ọkpụrụkpụ: 2–3 nm, nha n'akụkụ: 20–50 nm) ka a hụrụ site na iji igwe elektrọn nnyefe dị elu (HRTEM; Fig. Supplementary 1) na nha atomiki ike microscopy (AFM) (Fig. Supplementary 2). A hụkwara nchịkọta nke nanosheets n'ihi ọdịdị ha dị oke mkpa.
Usoro mgbasa ozi X-ray nke Ni(OH)2-NS na NiV-LDH-NS. FE, throughput, na njupụta ugbu a AA na b Ni(OH)2-NS na c NiV-LDH-NS na ikike dị iche iche. Ogwe njehie na-anọchite anya mgbanwe ọkọlọtọ nke nha atọ nọọrọ onwe ha site na iji otu ihe mkpali ahụ. onyonyo HRTEM nke NV-LDH-NS. Ogwe nha: 20 nm. Foto HAADF-STEM nke NiV-LDH-NS na maapụ elemental kwekọrọ na ya na-egosi nkesa nke Ni (akwụkwọ ndụ akwụkwọ ndụ), V (odo), na O (acha anụnụ anụnụ). Ogwe nha: 100 nm. f Ni 2p3/2, g O 1 s, na h V 2p3/2 data XPS nke Ni(OH)2-NS (elu) na NiV-LDH-NS (ala). i FE na j bụ arụmọrụ AA na ihe mkpali abụọ ahụ n'ime okirikiri 7. Ogwe njehie na-anọchite anya mgbanwe ọkọlọtọ nke nha atọ nọọrọ onwe ha site na iji otu ihe mkpali ahụ ma dị n'ime 10%. A na-enye data dị adị maka a–c na f–j na faịlụ data dị adị.
Anyị wee nyochaa mmetụta nke Ni(OH)2-NS na COR. Site na iji electrolysis ike na-adịgide adịgide, anyị nwetara 80% FE nke AA na obere ike (1.5 VRHE) na-enweghị OER (Foto 2b), na-egosi na COR dị mma karịa OER na obere ike anodic. A chọpụtara na ihe kachasị na-esite na ya bụ glutaric acid (GA) yana FE nke 3%. HPLC gụkwara ọnụnọ nke obere acid succinic (SA), malonic acid (MA), na oxalic acid (OA) (lee Foto Mgbakwunye 3 maka nkesa ngwaahịa). Achọpụtaghị formic acid na ngwaahịa ahụ, na-atụ aro na enwere ike ịmepụta carbonate dị ka ngwaahịa C1. Iji nwalee echiche a, a na-eme ka electrolyte sitere na electrolysis zuru oke nke 0.4 M cyclohexanone bụrụ acid ma gafere ngwaahịa gas ahụ site na ngwọta Ca(OH)2. N'ihi ya, ngwọta ahụ ghọrọ turbid, na-akwado nhazi nke carbonate mgbe electrolysis gasịrị. Agbanyeghị, n'ihi obere ọkụ eletrik a na-emepụta n'oge usoro electrolysis (Foto 2b, c), njupụta nke carbonate dị obere ma sie ike ịgụta. Na mgbakwunye, enwere ike ịmepụta ngwaahịa C2-C5 ndị ​​ọzọ, mana enweghị ike ịgụta ọnụọgụ ha. Ọ bụ ezie na ọ siri ike ịgụta ọnụọgụ ngwaahịa niile, 90% nke ngụkọta nha nhata electrochemical na-egosi na achọpụtala ọtụtụ usoro electrochemical, nke na-enye ntọala maka nghọta anyị na usoro. N'ihi obere njupụta ugbu a (20 mA cm−2), mkpụrụ nke AA bụ 97 μmol cm−2 h−1 (Foto 2b), nke hà nhata 19 mmol h−1 g−1 dabere na ibu nke catalyst (5 mg cm−2), nke dị ala karịa mmepụta catalytic okpomọkụ (~30 mmol h−1 g−1)1. Mgbe ike etinyere n'ọrụ mụbara site na 1.5 ruo 1.9 VRHE, ọ bụ ezie na njupụta ugbu a mụbara (site na 20 ruo 114 mA cm−2), n'otu oge ahụ, e nwere nnukwu mbelata na AA FE, site na 80% ruo 42%. Mbelata na FE na ikike ndị ka mma bụ isi n'ihi asọmpi maka OER. Karịsịa na 1.7 VRHE, asọmpi OER na-eduga na nnukwu mbelata na AA FE, si otú a belata arụmọrụ AA ntakịrị yana mmụba nke njupụta ugbu a. Ya mere, ọ bụ ezie na njupụta ugbu a nke AA mụbara site na 16 ruo 48 mA cm−2 na mmepụta AA mụbara (site na 97 ruo 298 μmol cm−2 h−1), e riri nnukwu ike ọzọ (2.5 W h gAA−1 karịa site na 1.5 ruo 1.9 VRHE), nke butere mmụba na mwepụta carbon nke 2.7 g CO2 gAA−1 (akọwapụtara na Ndekọ Mgbakwunye 1). OER a maara na mbụ dị ka onye na-asọmpi na mmeghachi omume COR na ikike anodic dị elu kwekọrọ na akụkọ ndị gara aga ma na-anọchite anya ihe ịma aka izugbe maka imeziwanye mmepụta AA14,17.
Iji mepụta ihe na-akpali akpali nke dabeere na Ni(OH)2-NS nke ka mma, anyị buru ụzọ nyochaa usoro ọrụ. Anyị hụrụ elu dị na 473 cm-1 na 553 cm-1 na nsonaazụ Raman spectroscopy anyị (Foto mgbakwunye 4), nke kwekọrọ na mgbagọ na ịgbatị nke njikọ Ni3+-O na NiOOH, n'otu n'otu. Edeela ya na NiOOH bụ nsonaazụ nke mbelata Ni(OH)2 na mkpokọta Ni(OH)O na ike anodic, ọ bụkwa usoro ọrụ na oxidation electrocatalytic20,21. Ya mere, anyị na-atụ anya na ime ka usoro nhazi nke Ni(OH)2 gaa na NiOOH dịkwuo ngwa ngwa nwere ike ime ka ọrụ catalytic nke COR ka mma.
Anyị gbalịrị ịgbanwe Ni(OH)2 site na iji ọla dị iche iche ebe ọ bụ na a hụrụ na mgbanwe heteroatom na-akwalite nhazi usoro na oxides/hydroxides metal transition 22,23,24. E ji njikọ nke Ni na ihe mgbakwunye metal nke abụọ mepụta ihe nlele ndị a. N'ime ihe nlele dị iche iche nke emezigharịrị metal, ihe nlele V-gbanwere (V:Ni atomic ratio 1:8) (a na-akpọ NiV-LDH-NS) gosipụtara njupụta ugbu a dị elu na COR (Foto mgbakwunye 5) na nke kachasị mkpa, AA FE dị elu n'elu windo nwere ike sara mbara. Karịsịa, na obere ike (1.5 VRHE), njupụta ugbu a nke NiV-LDH-NS dị elu ugboro 1.9 karịa nke Ni(OH)2-NS (39 vs. 20 mA cm−2), na AA FE yiri ya na ihe mkpali abụọ ahụ (83% vs. 80%). N'ihi njupụta ọkụ eletrik dị elu na FE AA yiri ya, mmepụta nke NiV-LDH-NS dị okpukpu 2.1 karịa nke Ni(OH)2-NS (204 vs. 97 μmol cm−2 h−1), na-egosi mmetụta nkwalite nke mgbanwe V na njupụta ọkụ eletrik dị ala (Foto 2c).
Site na mmụba nke ikike etinyere (dịka ọmụmaatụ, 1.9 VRHE), njupụta ugbu a na NiV-LDH-NS dị elu karịa nke dị na Ni(OH)2-NS (170 vs. 114 mA cm−2), mmụba ahụ yikwara nke dị na obere ikike (ugboro 1.9 karịa). Ihe pụrụ iche bụ na NiV-LDH-NS jigidere AA FE dị elu (83%) ma e belatara OER nke ukwuu (O2 FE 4%; Foto 2c), na-arụ ọrụ karịa Ni(OH)2-NS na ihe ndị na-akpali akpali akọọrọ na mbụ nwere obere AA FE na nnukwu ike anodic (Tebụl Mgbakwunye 1). N'ihi oke FE nke AA n'ime oghere nwere ike (1.5–1.9 VRHE), e nwetara ọsọ mmepụta AA nke 867 μmol cm−2 h−1 (nke kwekọrọ na 174.3 mmol g−1 h−1) na 1.9 VRHE, na-egosi arụmọrụ dị mma na sistemụ electrocatalytic na ọbụna thermocatalytic mgbe a na-eme ka ọrụ ahụ dị mma site na mkpokọta ibu nke ihe nlele NiV-LDH-NS (Foto mgbakwunye 6).
Iji ghọta njupụta dị elu nke ugbu a na FE dị elu n'ofe oke ike dị ukwuu mgbe anyị gbanwere Ni(OH)2 na V, anyị kọwara nhazi nke NiV-LDH-NS. Nsonaazụ XRD gosiri na mgbanwe ya na V mere ka mgbanwe nkebi site na β-Ni(OH)2 gaa na α-Ni(OH)2, a chọpụtaghịkwa ụdị kristal metụtara V ọ bụla (Fig. 2a). Nsonaazụ HRTEM na-egosi na NiV-LDH-NS na-eketa ọdịdị nke nanosheets Ni(OH)2-NS dị oke mkpa ma nwee nha akụkụ yiri ya (Fig. 2d). Nha AFM kpughere usoro nchịkọta siri ike nke nanosheets, nke butere ọkpụrụkpụ a na-atụ anya ya nke ihe dị ka 7 nm (Fig. Mgbakwunye 7), nke buru ibu karịa nke Ni(OH)2-NS (ọkpụrụkpụ: 2-3 nm). Nyocha maapụ X-ray spectroscopy (EDS) ike-agbasa (Fig. 2e) gosiri na ekesara ihe V na Ni nke ọma na nanosheets. Iji kọwaa nhazi eletrọniki nke V na mmetụta ya na Ni, anyị jiri X-ray photoelectron spectroscopy (XPS) (Foto 2f–h). Ni(OH)2-NS gosipụtara oke elu nke Ni2+ (elu nwanyị na 855.6 eV, elu satịlaịtị na 861.1 eV, Foto 2f)25. Enwere ike kewaa spectrum O 1 nke Ni(OH)2-NS n'ime oke atọ, nke gụnyere oke elu dị na 529.9, 530.9 na 532.8 eV na oxygen lattice (OL), hydroxyl group (Ni-OH) na oxygen a na-etinye na ntụpọ elu (OAds), n'otu n'otu (Foto 2g)26,27,28,29. Mgbe mgbanwe ahụ gasịrị na V, elu V 2p3/2 pụtara, nke enwere ike ịgbari n'ime elu atọ dị na 517.1 eV (V5+), 516.6 eV (V4+) na 515.8 eV (V3+), n'otu n'otu, na-egosi na ụdị V dị na nhazi ahụ dịkarịsịrị na ọnọdụ oxidation dị elu (Foto 2h)25,30,31. Na mgbakwunye, elu Ni 2p na 855.4 eV na NiV-LDH-NS gbanwere n'ụzọ na-adịghị mma (site na ihe dị ka 0.2 eV) ma e jiri ya tụnyere nke dị na Ni (OH)2-NS, na-egosi na e bufere elektrọn site na V gaa na Ni. Ọnọdụ valence dị ala nke Ni a hụrụ mgbe mgbanwe V gasịrị kwekọrọ na nsonaazụ Ni K-edge X-ray absorption near-edge spectroscopy (XANES) (lee ngalaba "V Mgbanwe Na-akwalite Mbelata Catalyst" n'okpuru maka nkọwa ndị ọzọ). A kpọrọ NiV-LDH-NS mgbe ọgwụgwọ COR gasịrị ruo otu awa ka a kpọrọ NiV-LDH-POST ma ejiri ihe ngosi elektrọn nnyefe, maapụ EDS, mgbasa ozi X-ray, Raman spectroscopy, na nha XPS mara ya nke ọma (Foto mgbakwunye 8 na 9). Ihe mkpali ndị ahụ nọgidere dị ka ihe nchịkọta nwere ọdịdị nanosheet dị gịrịgịrị (Foto mgbakwunye 8a–c). Nha kristal nke ihe nlele ahụ belatara ma ọdịnaya V belatara n'ihi ntapu V na nhazi nke ihe mkpali (Foto mgbakwunye 8d–f). Ụdị XPS gosipụtara mbelata na ike V kacha elu (Foto mgbakwunye 9), nke e kwuru na ọ bụ V leaching kpatara. Na mgbakwunye, nyocha nke spectrum O 1s (Foto mgbakwunye 9d) na nha electron paramagnetic resonance (EPR) (Foto mgbakwunye 10) gosiri na ọnụọgụ nke oghere oxygen na NiV-LDH-NS mụbara mgbe awa 1 nke electrolysis gasịrị, nke nwere ike ibute mgbanwe na-adịghị mma na ike njikọ Ni 2p (lee Fig Mgbakwunye 9 na 10 maka nkọwa ndị ọzọ)26,27,32,33. Ya mere, NiV-LDH-NS egosighi obere mgbanwe nhazi mgbe awa 1 nke COR gasịrị.
Iji gosi ọrụ dị mkpa nke V na-arụ n'ịkwalite COR, anyị mepụtara ihe mkpali NiV-LDH nwere oke atọm V:Ni dị iche iche (1:32, 1:16, na 1:4, nke akpọrọ NiV-32, NiV-16, na NiV-4, n'otu n'otu) ma e wezụga 1:8 site na otu usoro coprecipitation. Nsonaazụ maapụ EDS na-egosi na oke atọm V:Ni dị na ihe mkpali ahụ dị nso na nke precursor (Foto mgbakwunye 11a–e). Site na mmụba nke mgbanwe V, ike nke spectrum V 2p na-abawanye, ike njikọ nke mpaghara Ni 2p na-agbanwekwa gaa n'akụkụ na-adịghị mma mgbe niile (Foto mgbakwunye 12). N'otu oge ahụ, oke nke OL na-amụba nwayọ nwayọ. Nsonaazụ nke ule catalytic na-egosi na enwere ike igbochi OER nke ọma ọbụlagodi mgbe obere mgbanwe V gasịrị (V:Ni atomic ratio nke 1:32), ebe O2 FE na-ebelata site na 27% ruo 11% na 1.8 VRHE mgbe mgbanwe V gasịrị (Foto mgbakwunye 11f). Site na mmụba nke oke V:Ni site na 1:32 ruo 1:8, ọrụ catalytic mụbara. Agbanyeghị, site na mmụba ọzọ nke mgbanwe V (V:Ni ratio nke 1:4), njupụta ugbu a na-ebelata, nke anyị na-eche bụ n'ihi mbelata na njupụta nke ebe ọrụ Ni (karịsịa usoro ọrụ NiOOH; Fig. Mgbakwunye 11f). N'ihi mmetụta nkwalite nke mgbanwe V na nchekwa nke ebe ọrụ Ni, ihe na-akpali akpali nwere oke V:Ni nke 1:8 gosipụtara arụmọrụ FE na AA kachasị elu na ule nyocha oke V:Ni. Iji mee ka o doo anya ma oke V:Ni ka na-adịgide mgbe electrolysis gasịrị, a kọwara nhazi nke ihe na-akpali akpali ejiri. Nsonaazụ ya gosiri na maka ihe mkpali nwere oke V:Ni mbụ site na 1:16 ruo 1:4, oke V:Ni belatara ruo ihe dị ka 1:22 mgbe mmeghachi omume ahụ gasịrị, nke nwere ike ịbụ n'ihi mwepụ nke V n'ihi nhazi ihe mkpali (Foto mgbakwunye 13). Rịba ama na a hụrụ FE AA yiri ya mgbe oke V:Ni mbụ hà nhata ma ọ bụ karịa 1:16 (Foto mgbakwunye 11f), nke enwere ike ịkọwa site na nhazi ihe mkpali nke na-ebute oke V:Ni yiri ya na ihe mkpali na-egosi arụmọrụ ihe mkpali yiri ya.
Iji gosikwuo mkpa ọ dị na Ni(OH)2 nke V-gbanwere agbanwe n'ịkwalite arụmọrụ COR, anyị mepụtara ụzọ abụọ ọzọ e ji aka mee iji tinye V n'ime ihe Ni(OH)2-NS. Otu bụ ụzọ ngwakọta, a na-akpọkwa ihe nlele ahụ NiV-MIX; nke ọzọ bụ usoro sputtering n'usoro, a na-akpọkwa ihe nlele ahụ NiV-SP. Nkọwa nke njikọta ahụ dị na ngalaba Usoro. Mapping SEM-EDS gosiri na agbanwere V nke ọma na elu Ni(OH)2-NS nke ihe nlele abụọ ahụ (Foto mgbakwunye 14). Nsonaazụ electrolysis na-egosi na na 1.8 VRHE, arụmọrụ AA na NiV-MIX na NiV-SP electrodes bụ 78% na 79%, n'otu n'otu, ha abụọ na-egosi arụmọrụ ka elu karịa Ni(OH)2-NS (51%). Ọzọkwa, e gbochiri OER na NiV-MIX na NiV-SP electrodes (FE O2: 7% na 2%, n'otu n'otu) ma e jiri ya tụnyere Ni(OH)2-NS (FE O2: 27%). Nsonaazụ ndị a na-egosi mmetụta dị mma nke mgbanwe V na Ni(OH)2 na mgbochi OER (Foto mgbakwunye 14). Agbanyeghị, nkwụsi ike nke ihe mkpali ahụ mebiri emebi, nke gosipụtara site na mbelata nke FE AA na NiV-MIX ruo 45% na na NiV-SP ruo 35% mgbe usoro COR asaa gasịrị, nke na-egosi mkpa ọ dị iji usoro kwesịrị ekwesị iji mee ka ụdị V kwụsie ike, dị ka mgbanwe V na lattice Ni(OH)2 na NiV-LDH-NS, nke bụ isi ihe na-akpali akpali n'ọrụ a.
Anyị nyochakwara nkwụsi ike nke Ni(OH)2-NS na NiV-LDH-NS site n'itinye COR n'ọtụtụ okirikiri. Emere mmeghachi omume ahụ ruo awa 1 kwa okirikiri ma dochie electrolyte mgbe okirikiri ọ bụla gasịrị. Mgbe okirikiri nke asaa gasịrị, arụmọrụ FE na AA na Ni(OH)2-NS belatara site na 50% na 60%, n'otu n'otu, ebe a hụrụ mmụba na OER (Fig. 2i, j). Mgbe okirikiri ọ bụla gasịrị, anyị nyochachara usoro voltammetry cyclic (CV) nke ihe mkpali ma hụ na oke oxidation nke Ni2+ belatara nwayọ, na-egosi mbelata na ikike redox nke Ni (Fig. Mgbakwunye 15a–c). Tinyere mmụba na ntinye Nication na electrolyte n'oge electrolysis (Fig. Mgbakwunye 15d), anyị na-ekwu na mmebi arụmọrụ (mbelata FE na mmepụta AA) bụ n'ihi mwepụ nke Ni site na ihe mkpali ahụ, na-ebute mkpughe ka ukwuu nke ihe mgbakwunye Ni foam nke na-egosipụta ọrụ OER. N'ụzọ dị iche, NiV-LDH-NS belatara mbelata na mmepụta FE na AA ruo 10% (Foto 2i, j), na-egosi na mgbanwe V gbochiri Ni leaching nke ọma (Foto mgbakwunye 15d). Iji ghọta nkwụsi ike nke mgbanwe V, anyị mere mgbakọta echiche. Dịka akwụkwọ ndị gara aga34,35 si kwuo, enwere ike iji mgbanwe enthalpy nke usoro demetallization nke atọm metal n'elu ihe na-arụ ọrụ nke ihe na-akpali akpali dị ka nkọwa ezi uche dị na ya iji nyochaa nkwụsi ike nke ihe na-akpali akpali. Ya mere, a tụrụ anya mgbanwe enthalpy nke usoro demetallization nke atọm Ni na elu (100) nke Ni(OH)2-NS na NiV-LDH-NS e wughachiri (NiOOH na NiVOOH, n'otu n'otu) (a kọwara nkọwa nke ihe nlereanya ahụ na Nkọwa Mgbakwunye 2 na Fig. Mgbakwunye 16). E gosipụtara usoro demetallization nke Ni site na NiOOH na NiVOOH (Foto Mgbakwunye 17). Ọnụ ego ike nke demetallization Ni na NiVOOH (0.0325 eV) dị elu karịa nke dị na NiOOH (0.0005 eV), nke na-egosi na mgbanwe V na-eme ka nkwụsi ike nke NiOOH dịkwuo mma.
Iji gosi na mmetụta mgbochi OER na NiV-LDH-NS, ọkachasị na nnukwu ike anodic, e mere nchọpụta electrochemical mass spectrometry (DEMS) iji nyochaa nhazi O2 nwere ike ịdabere na ihe atụ dị iche iche. Nsonaazụ gosiri na na enweghị cyclohexanone, O2 na NiV-LDH-NS pụtara na ikike mbụ nke 1.53 VRHE, nke dị ntakịrị ala karịa nke O2 na Ni(OH)2-NS (1.62 VRHE) (Foto mgbakwunye 18). Nsonaazụ a na-egosi na mgbochi OER nke NiV-LDH-NS n'oge COR nwere ike ọ gaghị abụ n'ihi obere ọrụ OER ya dị n'ime ya, nke kwekọrọ na njupụta ugbu a dị ntakịrị elu na usoro linear sweep voltammetry (LSV) na NiV-LDH-NS karịa nke dị na Ni(OH)2-NS na-enweghị cyclohexanone (Foto mgbakwunye 19). Mgbe ewebatara cyclohexanone, evolushọn O2 nke na-egbu oge (ikekwe n'ihi uru thermodynamic nke COR) kọwara FE dị elu nke AA na mpaghara nwere ike dị ala. Ihe kacha mkpa bụ na ikike mmalite OER na NiV-LDH-NS (1.73 VRHE) na-egbu oge karịa nke dị na Ni(OH)2-NS (1.65 VRHE), nke kwekọrọ na FE dị elu nke AA na obere FE nke O2 na NiV-LDH-NS na ikike ndị ka mma (Foto 2c).
Iji ghọtakwuo mmetụta nkwalite nke mgbanwe V, anyị nyochachara kinetics mmeghachi omume OER na COR na Ni(OH)2-NS na NiV-LDH-NS site na ịtụ mkpọda Tafel ha. Ọ dị mkpa ịmara na njupụta dị ugbu a na mpaghara Tafel bụ n'ihi oxidation nke Ni2+ ruo Ni3+ n'oge ule LSV site na obere ikike ruo na nnukwu ike. Iji belata mmetụta nke oxidation Ni2+ na nha mkpọda COR Tafel, anyị buru ụzọ oxidize catalyst na 1.8 VRHE maka nkeji 10 wee mee ule LSV na ọnọdụ nyocha azụ, ya bụ, site na nnukwu ike ruo obere ike (Foto mgbakwunye 20). E ji 100% iR kwụọ ụgwọ emezi usoro LSV mbụ iji nweta mkpọda Tafel. N'enweghị cyclohexanone, mkpọda Tafel nke NiV-LDH-NS (41.6 mV dec−1) dị ala karịa nke Ni(OH)2-NS (65.5 mV dec−1), na-egosi na enwere ike ime ka kinetics OER dịkwuo mma site na mgbanwe V (Foto mgbakwunye 20c). Mgbe ewebatara cyclohexanone, mkpọda Tafel nke NiV-LDH-NS (37.3 mV dec−1) dị ala karịa nke Ni(OH)2-NS (127.4 mV dec−1), na-egosi na mgbanwe V nwere mmetụta kinetic doro anya na COR ma e jiri ya tụnyere OER (Foto mgbakwunye 20d). Nsonaazụ ndị a na-egosi na ọ bụ ezie na mgbanwe V na-akwalite OER ruo n'ókè ụfọdụ, ọ na-eme ka kinetics COR dị ngwa ngwa, na-ebute mmụba na FE nke AA.
Iji ghọta mmetụta nkwalite nke mgbanwe V dị n'elu na arụmọrụ nke FE na AA, anyị lekwasịrị anya na ọmụmụ usoro. Ụfọdụ akụkọ gara aga egosila na mgbanwe heteroatom nwere ike ibelata kristal nke ihe na-akpali akpali ma mụbaa mpaghara elu electrochemically active (EAS), si otú a na-amụba ọnụọgụ nke ebe ndị na-arụ ọrụ ma si otú a na-eme ka ọrụ catalytic ka mma36,37. Iji nyochaa ohere a, anyị mere nha ECSA tupu na mgbe emechara ọrụ electrochemical, nsonaazụ ya gosikwara na ECSA nke Ni(OH)2-NS na NiV-LDH-NS yiri ya (Foto mgbakwunye 21), na-ewepụ mmetụta nke njupụta ebe na-arụ ọrụ mgbe mgbanwe V gasịrị na mmụba catalytic.
Dịka ihe ọmụma a na-anabatakarị si dị, na electrooxidation nke Ni(OH)2-catalyzed nke alcohols ma ọ bụ ihe ndị ọzọ dị na nucleophilic, Ni(OH)2 na-ebu ụzọ tụfuo elektrọn na proton wee belata ya na NiOOH site na usoro electrochemical na ikike anodic ụfọdụ38,39,40,41. NiOOH e guzobere na-arụ ọrụ dị ka ụdị COR na-arụ ọrụ n'ezie iji wepụta hydrogen na elektrọn site na ihe ndị dị na nucleophilic site na usoro kemịkalụ iji mepụta ngwaahịa oxidized20,41. Agbanyeghị, a kọọla n'oge na-adịbeghị anya na ọ bụ ezie na mbelata na NiOOH nwere ike ịbụ usoro ikpebi ọnụego (RDS) maka electrooxidation nke mmanya na Ni(OH)2, dịka a tụrụ aro na akwụkwọ ndị na-adịbeghị anya, oxidation nke alcohols Ni3+ nwere ike ịbụ usoro mberede site na mbufe elektrọn na-abụghị redox site na orbitals na-enweghị onye nọ na Ni3+41,42. Site n'ọmụmụ ihe mekaniki akọpụtara n'otu akwụkwọ ahụ, anyị jiri dimethylglyoxime disodium salt octahydrate (C4H6N2Na2O2 8H2O) dị ka molekul nyocha iji jide nhazi Ni2+ ọ bụla sitere na mbelata Ni3+ n'oge COR (Foto mgbakwunye 22 na Ihe Ndekọ Mgbakwunye 3). Nsonaazụ gosiri nhazi nke Ni2+, na-akwado na mbelata kemịkalụ nke NiOOH na electrooxidation nke Ni(OH)2 mere n'otu oge n'oge usoro COR. Ya mere, ọrụ catalytic nwere ike ịdabere nke ukwuu na kinetics nke mbelata Ni(OH)2 na NiOOH. Dabere na ụkpụrụ a, anyị nyochachara ma mgbanwe nke V ga-eme ka mbelata nke Ni(OH)2 dịkwuo ngwa ngwa ma si otú a melite COR.
Anyị jiri usoro Raman mee ihe mbụ iji gosi na NiOOH bụ usoro ọrụ maka COR na Ni(OH)2-NS na NiV-LDH-NS site n'ileba anya na nhazi nke NiOOH na ikike dị mma na oriri ya mgbe ewebatara cyclohexanone, na-esochi usoro "electrochemical-chemical" a kpọtụrụ aha n'elu (Foto 3a). Ọzọkwa, mmeghachi omume nke NiV-LDH-NS e wughachiri karịrị nke Ni(OH)2-NS, dịka egosiri site na mfu ngwa ngwa nke mgbaàmà Raman Ni3+–O. Anyị gosiziri na NiV-LDH-NS gosipụtara ikike dị ala maka nhazi NiOOH ma e jiri ya tụnyere Ni(OH)2-NS n'ihu ma ọ bụ enweghị cyclohexanone (Foto 3b, c na Fig. Mgbakwunye 4c, d). Nke pụtara ìhè bụ na arụmọrụ OER dị elu nke NiV-LDH-NS na-eme ka ọtụtụ afụfụ na-arapara na lenso ihu nke ebumnuche nha Raman, nke na-eme ka elu Raman na 1.55 VRHE pụọ ​​(Foto Mgbakwunye 4d). Dịka nsonaazụ DEMS si kwuo (Foto mgbakwunye 18), njupụta ugbu a na obere ikike (VRHE < 1.58 maka Ni(OH)2-NS na VRHE < 1.53 maka NiV-LDH-NS) bụ isi n'ihi nrụgharị nke ion Ni2+ kama OER na enweghị cyclohexanone. Ya mere, oke oxidation nke Ni2+ na usoro LSV siri ike karịa nke NiV-LDH-NS, na-egosi na mgbanwe V na-enye NiV-LDH-NS ikike imegharị ihe ka mma (lee Fig. 19 maka nyocha zuru ezu).
a In situ Raman spectra nke Ni(OH)2-NS (aka ekpe) na NiV-LDH-NS (aka nri) n'okpuru ọnọdụ OCP mgbe emechara oxidation na 1.5 VRHE na 0.5 M KOH na 0.4 M cyclohexanone maka s60. b In situ Raman spectra nke Ni(OH)2-NS na c NiV-LDH-NS na 0.5 M KOH + 0.4 M cyclohexanone na potentials dị iche iche. d In situ XANES spectra nke Ni(OH)2-NS na NiV-LDH-NS na NiK-edge na 0.5 M KOH na e 0.5 M KOH na 0.4 M cyclohexanone. Inset na-egosi mpaghara spectral dị elu n'etiti 8342 na 8446 eV. f Valence states nke Ni na Ni(OH)2-NS na NiV-LDH-NS na potentials dị iche iche. g In situ Ni EXAFS spectra nke NiV-LDH-NS tupu na mgbe etinyere cyclohexanone na ikike dị iche iche. h Ụdị echiche nke Ni(OH)2-NS na NiV-LDH-NS. N'elu: Na Ni(OH)2-NS, nhazigharị nwayọ site na Ni(OH)2-NS gaa na NiOOH na-arụ ọrụ dị ka RDS, ebe cyclohexanone na-ebelata ụdị Ni-valent dị elu site na usoro kemịkalụ iji nọgide na-enwe ọnọdụ Ni-valent dị ala iji mepụta AA. N'ala: Na NiV-LDH-NS, nhazigharị ahụ na-eme ka mgbanwe V dị mfe, na-ebute mbufe nke RDS site na nzọụkwụ nhazigharị gaa na nzọụkwụ kemịkalụ. i Ike efu nke Gibbs na-agbanwe mgbe nwughari nke Ni(OH)2-NS na NiV-LDH-NS. A na-enye data raw maka aj na i na faịlụ data raw.
Iji nyochaa mgbanwe nke usoro atọm na eletrọniki n'oge mbelata ihe mkpali, anyị mere nnwale X-ray absorption spectroscopy (XAS) in situ, nke nyere ngwaọrụ dị ike iji nyochaa ike nke ụdị Ni na usoro atọ sochiri onwe ha: OER, injection cyclohexanone, na COR na open circuit potential (OCP). Foto a na-egosi spectra K-edge XANES nke Ni nwere ike ịbawanye tupu na mgbe a gbanyere cyclohexanone (Foto 3d, e). N'otu ikike ahụ, ike absorption nke NiV-LDH-NS dị mma karịa nke Ni(OH)2-NS (Foto 3d, e, inset). A na-eme atụmatụ nkezi valence nke Ni n'okpuru ọnọdụ ọ bụla site na njikọta linear nke spectra XANES na nlọghachi nke mgbanwe ike absorption Ni K (Foto 3f), yana spectrum ntụaka ewepụtara na akwụkwọ ebipụtara (Foto mgbakwunye 23)43.
Na nzọụkwụ mbụ (tupu mmalite nke cyclohexanone, nke kwekọrọ na usoro OER; Foto 3f, aka ekpe), na ikike nke ihe mkpali a na-agbanwebeghị (<1.3 VRHE), ọnọdụ valence nke Ni na NiV-LDH-NS (+1.83) dị ntakịrị ala karịa nke NiV-LDH-NS (+1.97), nke enwere ike ịkọwa na mbufe eletrọn site na V gaa na Ni, kwekọrọ na nsonaazụ XPS ndị a kpọtụrụ aha n'elu (Foto 2f). Mgbe ikike gafere ebe mbelata (1.5 VRHE), ọnọdụ valence nke Ni na NiV-LDH-NS (+3.28) na-egosi mmụba doro anya karịa ma e jiri ya tụnyere nke Ni(OH)2-NS (+2.49). Na ikike dị elu (1.8 VRHE), ọnọdụ valence nke ihe ndị Ni nwetara na NiV-LDH-NS (+3.64) dị elu karịa nke Ni(OH)2-NS (+3.47). Dịka akụkọ ndị e bipụtara n'oge na-adịbeghị anya si kwuo, usoro a kwekọrọ na nhazi nke ụdị Ni4+ dị elu na nhazi nke Ni3+xOOH1-x (Ni3+x bụ ụdị Ni3+ na Ni4+ agwakọta), nke egosila na mbụ mmụba na ọrụ catalytic na mwepụ nke mmanya na-aba n'anya38,39,44. Ya mere, arụmọrụ ka mma nke NiV-LDH-NS na COR nwere ike ịbụ n'ihi mmụba na mbelata iji mepụta ụdị Ni-valent dị elu na-arụ ọrụ catalytic.
N'ọkwa nke abụọ (iwebata cyclohexanone mgbe e meghere mgbanaka, Foto 3f), ọnọdụ valence nke Ni na ihe mkpali abụọ ahụ belatara nke ukwuu, nke kwekọrọ na usoro mbelata nke Ni3+xOOH1-x site na cyclohexanone, nke kwekọrọ na nsonaazụ nke in situ Raman spectroscopy (Foto 3a), na ọnọdụ valence nke Ni fọrọ nke nta ka ọ gbakee na ọnọdụ mbụ (nzọụkwụ mbụ na obere ike), na-egosi mgbanwe nke usoro redox nke Ni ruo Ni3+xOOH1-x.
Na nzọụkwụ nke atọ (usoro COR) na ikike COR (1.5 na 1.8 VRHE; Foto 3f, aka nri), ọnọdụ valence nke Ni na Ni(OH)2-NS mụbara naanị ntakịrị (+2.16 na +2.40), nke dị obere karịa na otu ikike ahụ na nzọụkwụ mbụ (+2.49 na +3.47). Nsonaazụ ndị a na-egosi na mgbe a gbanyere cyclohexanone, a na-ebelata COR site na oxidation nwayọ nke Ni2+ ruo Ni3+x (ya bụ, nhazi Ni) kama site na usoro kemịkalụ dị n'etiti NiOOH na cyclohexanone na Ni(OH)2-NS, nke na-ahapụ Ni na ọnọdụ valence dị ala. Ya mere, anyị na-ekwubi na nhazi Ni nwere ike ije ozi dị ka RDS na usoro COR na Ni(OH)2-NS. N'ụzọ dị iche, NiV-LDH-NS nọgidere na-enwe oke valence nke ụdị Ni (>3) n'oge usoro COR, valence ahụ belatara nke ukwuu (erughị 0.2) ma e jiri ya tụnyere nzọụkwụ mbụ na otu ike ahụ (1.65 na 1.8 VRHE), na-egosi na mgbanwe V ahụ kwalitere oxidation nke Ni2+ ruo Ni3+x site na kinetic, na-eme ka usoro mbelata Ni dị ngwa karịa usoro kemịkalụ nke mbelata cyclohexanone. Nsonaazụ X-ray absorption fine structure (EXAFS) agbatịkwara kpughee mgbanwe zuru oke nke njikọ Ni–O (site na 1.6 ruo 1.4 Å) na Ni–Ni(V) (site na 2.8 ruo 2.4 Å) n'ihu cyclohexanone. Nke a kwekọrọ na nwughari nke usoro Ni(OH)2 gaa na usoro NiOOH na mbelata kemịkalụ nke usoro NiOOH site na cyclohexanone (Foto 3g). Agbanyeghị, cyclohexanone gbochiri nke ukwuu mbelata nke kinetics nke Ni(OH)2-NS (lee Ihe Ndekọ Mgbakwunye 4 na Fig. Mgbakwunye 24 maka nkọwa ndị ọzọ).
N'ozuzu, na Ni(OH)2-NS (Foto 3h, n'elu), usoro mbelata nwayọ site na usoro Ni(OH)2 ruo na usoro NiOOH nwere ike ije ozi dị ka RDS nke usoro COR dum kama usoro kemịkalụ nke mmepụta AA site na cyclohexanone n'oge mbelata kemịkalụ nke NiOOH. Na NiV-LDH-NS (Foto 3h, ala), mgbanwe V na-eme ka kinetics oxidation nke Ni2+ dịkwuo elu ruo Ni3+x, si otú a na-eme ka nhazi nke NiVOOH dịkwuo ngwa ngwa (kama oriri site na mbelata kemịkalụ), nke na-agbanwe RDS gaa na usoro kemịkalụ. Iji ghọta nhazi Ni nke mgbanwe V kpatara, anyị mere mgbakọta echiche ndị ọzọ. Dịka egosiri na Fig. 3h, anyị mere ka usoro nhazi nke Ni(OH)2-NS na NiV-LDH-NS dị ka ihe atụ. A na-ewepụ otu hydroxyl lattice na Ni(OH)2-NS na NiV-LDH-NS site na iwepụta OH- na electrolyte iji mepụta oxygen lattice na-enweghị electron. Mmeghachi omume kemịkalụ ndị kwekọrọ bụ ndị a:
A gbakọrọ mgbanwe ike efu nke Gibbs nke nhazigharị ahụ (Foto 3i), NiV-LDH-NS (0.81 eV) gosikwara obere mgbanwe ike efu nke Gibbs karịa Ni(OH)2-NS (1.66 eV), nke na-egosi na mgbanwe V belatara voltaji achọrọ maka nhazigharị Ni. Anyị kwenyere na ịkwalite nhazigharị ahụ nwere ike ibelata ihe mgbochi ike nke COR dum (lee ọmụmụ usoro mmeghachi omume n'okpuru maka nkọwa zuru ezu), si otú a mee ka mmeghachi omume ahụ dịkwuo ngwa ngwa na njupụta ugbu a dị elu.
Nnyocha dị n'elu na-egosi na mgbanwe V na-akpata nhazi ngwa ngwa nke Ni(OH)2, si otú a na-amụba ọnụego mmeghachi omume na, njupụta nke COR ugbu a. Agbanyeghị, saịtị Ni3+x nwekwara ike ịkwalite ọrụ OER. Site na usoro LSV na-enweghị cyclohexanone, o doro anya na njupụta ugbu a nke NiV-LDH-NS dị elu karịa nke Ni(OH)2-NS (Foto mgbakwunye 19), nke na-eme ka mmeghachi omume COR na OER mepụta mmeghachi omume asọmpi. Ya mere, enweghị ike ịkọwa FE dị elu nke AA karịa nke NiV-LDH-NS site na mgbanwe V na-akwalite nhazi usoro.
A na-anabatakarị na n'ime ihe ndị na-emepụta ihe na alkaline, mmeghachi omume electrooxidation nke ihe ndị na-emepụta nucleophilic na-agbasokarị ihe nlereanya Langmuir-Hinshelwood (LH). N'ụzọ doro anya, a na-ejikọta ihe ndị na-emepụta ihe na OH− anions n'elu ihe na-emepụta ihe, a na-etinyekwa OH− n'ime otu hydroxyl na-arụ ọrụ (OH*), nke na-eje ozi dị ka electrophiles maka oxidation nke nucleophiles, usoro nke egosila na mbụ site na data nnwale na/ma ọ bụ mgbakọ echiche45,46,47. Ya mere, njupụta nke ihe ndị na-emepụta ihe na oke ha (ihe ndị dị ndụ na OH−) nwere ike ijikwa mkpuchi ihe ndị na-emepụta ihe nke elu ihe na-emepụta ihe, si otú a na-emetụta FE na mmepụta nke ngwaahịa ebumnuche14,48,49,50. N'ọnọdụ anyị, anyị na-eche na mkpuchi elu cyclohexanone dị elu na NiV-LDH-NS na-akwado usoro COR, na n'aka nke ọzọ, mkpuchi elu cyclohexanone dị ala na Ni(OH)2-NS na-akwado usoro OER.
Iji nwalee echiche dị n'elu, anyị buru ụzọ mee usoro nnwale abụọ metụtara mkpokọta nke ihe ndị na-emeghachi omume (C, cyclohexanone, na COH−). Emere nnwale mbụ ahụ na electrolysis na ikike na-adịgide adịgide (1.8 VRHE) na ihe ndị na-eme ka ihe dị na Ni(OH)2-NS na NiV-LDH-NS nwere ọdịnaya cyclohexanone C dị iche iche (0.05 ~ 0.45 M) na ọdịnaya COH− edobere (0.5 M). Mgbe ahụ, a gbakọọ mmepụta FE na AA. Maka ihe na-eme ka ihe dị na NiV-LDH-NS, mmekọrịta dị n'etiti mmepụta AA na cyclohexanone C gosipụtara usoro "ụdị mgbawa ugwu" nkịtị na ọnọdụ LH (Fig. 4a), na-egosi na mkpuchi cyclohexanone dị elu na-asọmpi na OH− absorption. Ọ bụ ezie na maka Ni(OH)2-NS, mmepụta AA mụbara n'otu aka ahụ site na mmụba nke C nke cyclohexanone site na 0.05 ruo 0.45 M, nke na-egosi na ọ bụ ezie na nnukwu mkpokọta nke cyclohexanone dị elu (0.45 M), mkpuchi elu ya ka dị obere. Na mgbakwunye, site na mmụba nke COH− ruo 1.5 M, a hụrụ usoro "ụdị mgbawa" na Ni(OH)2-NS dabere na C nke cyclohexanone, ebe ntụgharị nke arụmọrụ ahụ kwụsịtụrụ ma e jiri ya tụnyere NiV-LDH-NS, nke na-egosikwa na cyclohexanone adịghị ike na Ni(OH)2-NS (Foto mgbakwunye 25a na Note 5). Tinyere nke ahụ, FE nke AA na NiV-LDH-NS nwere mmetụta dị ukwuu na C-cyclohexanone ma mụbaa ngwa ngwa ruo ihe karịrị 80% mgbe amụbawanye C-cyclohexanone site na 0.05 M ruo 0.3 M, na-egosi na cyclohexanone dị mfe ịba ụba na NiV-LDH-NS (Foto 4b). N'ụzọ dị iche, ịbawanye njupụta nke C-cyclohexanone emeghị ka OER dị na Ni(OH)2-NS nke ukwuu, nke nwere ike ịbụ n'ihi enweghị nnabata zuru oke nke cyclohexanone. N'aka nke ọzọ, nyocha ọzọ nke ịdabere na COH− na arụmọrụ catalytic gosikwara na a ka mma itinye cyclohexanone na NiV-LDH-NS, nke nwere ike ịnagide COH− dị elu n'oge usoro COR na-ebelataghị FE nke AA (Foto mgbakwunye 25b, c na Note 5).
Mmepụta nke AA na EF nke b Ni(OH)2-NS na NiV-LDH-NS na cyclohexanone nwere C dị iche na 0.5 M KOH. c Ike adsorption nke cyclohexanone na NiOOH na NiVOOH. d FE nke AA na Ni(OH)2-NS na NiV-LDH-NS na 0.5 M KOH na 0.4 M cyclohexanone na 1.80 VRHE site na iji atụmatụ ndị nwere ike na-aga n'ihu na nke na-adịgide adịgide. Ogwe njehie na-anọchite anya mgbanwe ọkọlọtọ nke nha atọ nọọrọ onwe ha site na iji otu ihe atụ ahụ ma dị n'ime 10%. e N'elu: Na Ni(OH)2-NS, cyclohexanone nwere mpaghara ala dị ala C na-abanye nke ọma, na-ebute asọmpi siri ike maka OER. N'ala: Na NiV-LDH-NS, a na-ahụ nnukwu mkpokọta cyclohexanone C na mmụba nke adsorption nke cyclohexanone, na-ebute mmechi nke OER. A na-enye data raw maka a–d na faịlụ data raw.
Iji nwalee mmụba nke cyclohexanone na NiV-LDH-NS, anyị jiri electrochemical coupled quartz kristal microbalance (E-QCM) iji nyochaa mgbanwe oke nke ụdị ihe ndị a na-etinye n'ime mmiri n'oge. Nsonaazụ gosiri na ikike mbụ nke cyclohexanone na NiV-LDH-NS buru ibu okpukpu 1.6 karịa nke dị na Ni(OH)2-NS na steeti OCP, ọdịiche a na ikike adsorption mụbara ka ikike ahụ mụbara ruo 1.5 VRHE (Foto mgbakwunye 26). Emere mgbakọ DFT nke a na-akpọ spin-polarized iji nyochaa omume adsorption nke cyclohexanone na NiOOH na NiVOOH (Foto 4c). Cyclohexanone na-abanye n'ime etiti Ni dị na NiOOH site na ike adsorption (Eads) nke -0.57 eV, ebe cyclohexanone nwere ike ịbanye n'ime etiti Ni ma ọ bụ etiti V dị na NiVOOH, ebe etiti V na-enye Eads dị ala karịa (-0.69 eV), dịka a hụrụ na adsorption siri ike nke cyclohexanone dị na NiVOOH.
Iji gosikwuo na mmụba nke cyclohexanone nwere ike ịkwalite mmepụta AA ma gbochie OER, anyị jiri atụmatụ ike na-aga n'ihu mee ka cyclohexanone baa ọgaranya na elu catalyst (maka Ni(OH)2-NS na NiV-LDH-NS), nke sitere na akụkọ ndị gara aga. 51, 52 N'ụzọ doro anya, anyị tinyere ike nke 1.8 VRHE na COR, wee gbanwee ya na steeti OCP, wee gbanwee ya azụ na 1.8 VRHE. N'okwu a, cyclohexanone nwere ike ịgbakọta na elu catalyst na steeti OCP n'etiti electrolyses (lee ngalaba Usoro maka usoro zuru ezu). Nsonaazụ gosiri na maka Ni(OH)2-NS na NiV-LDH-NS, iji electrolysis ike na-aga n'ihu meziwanye arụmọrụ catalytic ma e jiri ya tụnyere electrolysis ike na-aga n'ihu (Foto 4d). Ihe pụrụ iche bụ na Ni(OH)2-NS gosipụtara mmụba dị ukwuu na COR (AA FE: site na 51% ruo 82%) na igbochi OER (O2 FE: site na 27% ruo 4%) karịa NiV-LDH-NS, nke e kwuru na ọ bụ eziokwu na enwere ike ime ka mkpokọta cyclohexanone ka mma karịa na ihe na-akpali akpali nwere ikike adsorption na-adịghị ike (ya bụ, Ni(OH)2-NS) site na electrolysis nwere ike ime mgbe ụfọdụ.
N'ozuzu, a pụrụ ikwu na mgbochi nke OER na NiV-LDH-NS bụ n'ihi mmụba nke cyclohexanone (Foto 4e). Na Ni(OH)2-NS (Foto 4e, n'elu), adịghị ike nke cyclohexanone butere mkpuchi cyclohexanone dị obere na mkpuchi OH* dị elu na elu ihe na-akpali akpali. Ya mere, oke ụdị OH* ga-eduga na asọmpi siri ike maka OER ma belata FE nke AA. N'ụzọ dị iche, na NiV-LDH-NS (Foto 4e, ala), mgbanwe V mụbara ikike adsorption nke cyclohexanone, si otú a na-amụba elu C nke cyclohexanone ma jiri ụdị OH* a na-etinye n'ime ya nke ọma maka COR, na-akwalite nhazi AA ma na-egbochi OER.
Na mgbakwunye na inyocha mmetụta nke mgbanwe V na nhazigharị nke ụdị Ni na adsorption cyclohexanone, anyị nyochakwara ma V ọ na-agbanwe ụzọ nhazi AA site na COR. A tụpụtara ọtụtụ ụzọ COR dị iche iche n'akwụkwọ ndị a, anyị nyochakwara ohere ha nwere na sistemụ mmeghachi omume anyị (lee Fig. Mgbakwunye 27 na Ihe Ndetu Mgbakwunye 6 maka nkọwa ndị ọzọ)13,14,26. Nke mbụ, akọpụtala na nzọụkwụ mbụ nke ụzọ COR nwere ike ịgụnye oxidation mbụ nke cyclohexanone iji mepụta isi etiti 2-hydroxycyclohexanone (2)13,14. Iji chọpụta usoro ahụ, anyị jiri 5,5-dimethyl-1-pyrrolidine N-oxide (DMPO) iji jide ndị etiti na-arụ ọrụ nke a na-etinye n'elu ihe na-akpali akpali ma mụọ EPR. Nsonaazụ EPR gosiri ọnụnọ nke radicals C-centered (R) na hydroxyl radicals (OH) na ihe mkpali abụọ ahụ n'oge usoro COR, na-egosi na mwepụta Cα − H nke cyclohexanone na-emepụta ihe mgbakasị enolate etiti (1), nke OH* na-eme ka ọ gbapụta ọzọ iji mepụta 2 (Fig. 5a na Fig. Mgbakwunye 28). Ọ bụ ezie na achọpụtara otu ihe mgbakasị ahụ na ihe mgbakasị ahụ abụọ ahụ, akụkụ mpaghara nke akara R na NiV-LDH-NS dị elu karịa nke Ni(OH)2-NS, nke nwere ike ịbụ n'ihi ikike adsorption ka mma nke cyclohexanone (Tebụl Mgbakwunye 3 na Rịba ama 7). Anyị jiri 2 na 1,2-cyclohexanedione (3) dị ka ihe na-amalite mmeghachi omume maka electrolysis iji nwalee ma V ga-agbanwe usoro oxidation na-esote. Nsonaazụ electrolysis nke ndị nwere ike ime ihe (2 na 3) na Ni(OH)2-NS na NiV-LDH-NS gosiri nhọrọ ngwaahịa yiri nke ahụ, na-egosi na mmeghachi omume COR na Ni(OH)2-NS ma ọ bụ NiV-LDH-NS gara site na ụzọ ndị yiri ya (Foto 5b). Ọzọkwa, AA bụ ngwaahịa bụ isi naanị mgbe ejiri 2 dị ka ihe mmeghachi omume, na-atụ aro na enwetara AA site na usoro oxidation kpọmkwem site na nkewa nke njikọ Cα − Cβ nke 2 kama oxidation na-esote gaa na 3 na ihe mkpali abụọ ahụ, ebe ọ bụ na a gbanwere ya ka ọ bụrụ GA mgbe ejiri 3 dị ka ihe mmeghachi omume mmalite (Foto mgbakwunye 29, 30).
Ihe mgbaàmà EPR nke NiV-LDH-NS na 0.5 M KOH + 0.4 M cyclohexanone. b Nsonaazụ nke nyocha electrocatalytic nke 2-hydroxycyclohexanone (2) na 1,2-cyclohexanedione (3). Emere electrolysis na 0.5 M KOH na 0.1 M 2 ma ọ bụ 3 na 1.8 VRE maka otu awa. Ogwe njehie na-anọchite anya mgbanwe ọkọlọtọ nke nha abụọ nọọrọ onwe ha site na iji otu ihe mkpali ahụ. c Ụzọ mmeghachi omume akwadoro nke COR na ihe mkpali abụọ ahụ. d Ihe atụ atụmatụ nke ụzọ COR na Ni(OH)2-NS (aka ekpe) na d NiV-LDH-NS (aka nri). Àkwà uhie na-egosi usoro ndị mgbanwe V na-akwalite na usoro COR. A na-enye data dị adị maka a na b na faịlụ data dị adị.
N'ozuzu, anyị gosiri na Ni(OH)2-NS na NiV-LDH-NS na-akwalite COR site na ụzọ yiri nke ahụ: a na-etinye cyclohexanone n'elu ihe na-akpali akpali, na-eme ka mmiri ghara ịdị ma na-efunahụ elektrọn iji mepụta 1, nke OH* na-eme ka ọ dị ọcha ka ọ bụrụ 2, wee soro mgbanwe dị iche iche iji mepụta AA (Foto 5c). Agbanyeghị, mgbe ejiri cyclohexanone mee ihe dị ka ihe na-akpali akpali, a hụrụ asọmpi OER naanị na Ni(OH)2-NS, ebe a na-anakọta obere oxygen mgbe ejiri 2 na 3 mee ihe dị ka ihe na-akpali akpali. Ya mere, ọdịiche a hụrụ na arụmọrụ ihe na-akpali akpali nwere ike ịbụ n'ihi mgbanwe na mgbochi ike RDS na ikike nnabata cyclohexanone nke mgbanwe V kpatara kama mgbanwe na ụzọ mmeghachi omume. Ya mere, anyị nyochachara RDS nke ụzọ mmeghachi omume na ihe na-akpali akpali abụọ ahụ. Nsonaazụ X-ray acoustic spectroscopy nke a kpọtụrụ aha n'elu na-egosi na mgbanwe V na-agbanwe RDS na mmeghachi omume COR site na ọkwa nhazigharị gaa na ọkwa kemịkalụ, na-eme ka usoro NiOOH na ụdị Ni dị elu dịgide na NiV-LDH-NS (Fig. 3f, Fig. 24, na Note 4). Anyị nyochakwara usoro mmeghachi omume nke njupụta dị ugbu a nọchiri anya ya na akụkụ ọ bụla nke mpaghara dị iche iche nwere ike ime n'oge nha CV (lee Fig. 31 na Note 8 maka nkọwa zuru ezu) ma mee nnwale mgbanwe isotope H/D, nke gosipụtara n'otu aka na RDS nke COR na NiV-LDH-NS gụnyere nkewa nke njikọ Cα − H na ọkwa kemịkalụ kama ọkwa mbelata (lee Fig. 32 na Note 8 maka nkọwa ndị ọzọ).
Dabere na nyocha dị n'elu, a na-egosi mmetụta zuru oke nke mgbanwe V na Foto 5d. Ihe mkpali Ni(OH)2-NS na NiV-LDH-NS na-agbanwegharị elu na ikike anodic dị elu ma na-akpali COR site na ụzọ yiri ya. Na Ni(OH)2-NS (Foto 5d, aka ekpe), nzọụkwụ nhazigharị bụ RDS n'oge usoro COR; ebe na NiV-LDH-NS (Foto 5d, aka nri), mgbanwe V mere ka usoro nhazigharị ahụ dịkwuo ngwa ngwa ma gbanwee RDS ka ọ bụrụ Cα−H dehydrogenation nke cyclohexanone ka ọ bụrụ 1. Na mgbakwunye, adsorption cyclohexanone mere na saịtị V ma emelitere na NiV-LDH-NS, nke nyere aka na mgbochi nke OER.
N'ịtụle arụmọrụ electrocatalytic dị mma nke NiV-LDH-NS nwere FE dị elu n'ofe oke ike dị iche iche, anyị chepụtara MEA iji nweta mmepụta AA na-aga n'ihu. E ji NiV-LDH-NS chịkọta MEA dị ka anode, PtRu/C azụmahịa dị ka cathode53 na akpụkpọ mgbanwe anion (ụdị: FAA-3-50) (Foto 6a na Foto Mgbakwunye 33)54. Ebe ọ bụ na voltaji sel belatara ma FE nke AA yiri 0.5 M KOH na ọmụmụ ihe dị n'elu, e mere ka ntinye anolyte ka mma ruo 1 M KOH (Foto Mgbakwunye 25c). Egosiri usoro LSV e dekọrọ na Foto Mgbakwunye 34, na-egosi na arụmọrụ COR nke NiV-LDH-NS dị elu karịa nke Ni(OH)2-NS. Iji gosi na NiV-LDH-NS dị elu, e mere electrolysis nke na-agbanwe agbanwe site na njupụta nke ugbu a site na 50 ruo 500 mA cm−2 ma dekọọ voltaji sel kwekọrọ na ya. Nsonaazụ gosiri na NiV-LDH-NS gosipụtara voltaji sel nke 1.76 V na njupụta ugbu a nke 300 mA cm−2, nke dị ihe dị ka 16% ala karịa nke Ni(OH)2-NS (2.09 V), na-egosi arụmọrụ ike ya dị elu na mmepụta AA (Fig. 6b).
Ihe osise eserese nke batrị mmiri. b Voltaji sel na-enweghị ụgwọ iR na Ni(OH)2-NS na NiV-LDH-NS na 1 M KOH na 0.4 M cyclohexanone na njupụta dị iche iche nke ugbu a. c AA na FE na-enye na Ni(OH)2-NS na NiV-LDH-NS na njupụta dị iche iche nke ugbu a. Ogwe njehie na-anọchite anya mgbanwe ọkọlọtọ nke nha abụọ nọọrọ onwe ha site na iji otu ihe mkpali ahụ. d Ntụnyere nke arụmọrụ catalytic nke ọrụ anyị na sistemụ batrị mmiri ndị ọzọ akọpụtara14,17,19. E depụtara paramita mmeghachi omume na njirimara mmeghachi omume n'ụzọ zuru ezu na Tebụl Mgbakwunye 2. e Voltaji sel na FE nke AA na NiV-LDH-NS na 200 na 300 mA cm−2 na ule ogologo oge, n'otu n'otu. E nyere data mmiri maka be dị ka faịlụ data mmiri.
Ka ọ dịgodị, dịka egosiri na Fig. 6c, NiV-LDH-NS jigidere ezigbo FE (83% ruo 61%) na njupụta ugbu a dị elu (200 ruo 500 mA cm-2), si otú a na-eme ka mmepụta AA ka mma (1031 ruo 1900 μmol cm-2 h-1). Ka ọ dịgodị, naanị 0.8% nke anions adipic acid ka a hụrụ na ngalaba kathode mgbe electrolysis gasịrị, na-egosi na mgbanwe cyclohexanone adịghị mkpa n'ọnọdụ anyị (Foto mgbakwunye 35). N'ụzọ dị iche, na otu mmụba nke njupụta ugbu a, FE nke AA na Ni(OH)2-NS belatara site na 61% ruo 34%, nke mere ka o sie ike imeziwanye mmepụta AA (762 ruo 1050 μmol cm-2 h-1). Karịsịa, arụmọrụ nke AA belatara ntakịrị n'ihi asọmpi siri ike sitere na OER, ya mere FE nke AA belatara nke ukwuu ka mmụba nke njupụta ugbu a (site na 200 ruo 250 mA cm−2, Foto Mgbakwunye 5). Dịka anyị maara, nsonaazụ catalytic site na iji MEA na NiV-LDH-NS catalysts karịrị arụmọrụ nke reactors mmiri akọpụtara na mbụ nwere catalysts dabere na Ni (Tebụl Mgbakwunye 2). Ọzọkwa, dịka egosiri na Fig. 6d, NiV-LDH-NS gosipụtara uru dị ukwuu n'ihe gbasara njupụta ugbu a, voltaji sel, na FE nke AA ma e jiri ya tụnyere catalyst kacha arụ ọrụ Co-based, ya bụ, Co3O4 nke graphene kwadoro (Co3O4/GDY)17. Tinyere nke a, anyị nyochachara oriri ike nke mmepụta AA ma gosi na oriri AA dị obere nke ukwuu, naanị 2.4 W h gAA-1 na njupụta ugbu a nke 300 mA cm-2 na voltaji sel nke 1.76 V (a na-enye mgbakọta zuru ezu na Nkọwa Mgbakwunye 1). Ma e jiri ya tụnyere nsonaazụ kacha mma nke 4.1 W h gAA-1 maka Co3O4/GDY akọọrọ na mbụ, oriri ike maka mmepụta AA n'ọrụ anyị belatara site na 42% ma mụbaa mmepụta ahụ site na ugboro anọ (1536 vs. 319 μmol cm-2 h-1)17.
A tụlere nkwụsi ike nke ihe na-akpali akpali NiV-LDH-NS maka mmepụta AA ogologo oge na MEA na njupụta dị ugbu a nke 200 na 300 mA cm-2, n'otu n'otu (Foto 6e). Ebe ọ bụ na a na-eri OH− ngwa ngwa na njupụta dị elu nke ugbu a, ọnụego mmeghari elektrọl na 300 mA cm-2 dị elu karịa nke dị na 200 mA cm-2 (lee obere ngalaba "Nha elektrọnik" maka nkọwa zuru ezu). Na njupụta dị ugbu a nke 200 mA cm-2, nkezi arụmọrụ COR bụ 93% na awa 6 mbụ, wee belata ntakịrị ruo 81% mgbe awa 60 gasịrị, ebe voltaji sel mụbara ntakịrị site na 7% (site na 1.62 V ruo 1.73 V), na-egosi ezigbo nkwụsi ike. Ka njupụta dị ugbu a na-arị elu ruo 300 mA cm−2, arụmọrụ AA ka fọrọ nke nta ka ọ ghara ịgbanwe agbanwe (belatara site na 85% ruo 72%), mana voltaji sel mụbara nke ukwuu (site na 1.71 ruo 2.09 V, nke kwekọrọ na 22%) n'oge ule awa 46 (Foto 6e). Anyị na-eche na isi ihe kpatara mmebi arụmọrụ bụ mmebi nke akpụkpọ ahụ mgbanwe anion (AEM) site na cyclohexanone, nke na-eduga na mmụba na nguzogide sel na voltaji nke sel electrolyzer (Foto mgbakwunye 36), yana obere mmịpụta nke electrolyte site na anode gaa na cathode, na-ebute mbelata na olu anolyte na mkpa ịkwụsị electrolysis. Na mgbakwunye, mbelata na FE nke AA nwekwara ike ịbụ n'ihi mmịpụta nke ihe na-akpali akpali, nke na-akwado mmeghe nke ụfụfụ Ni maka OER. Iji gosi mmetụta nke AEM mebiri emebi na mmebi nke nkwụsi ike na 300 mA cm−2, anyị jiri AEM ọhụrụ dochie ya mgbe awa 46 nke electrolysis gasịrị. Dịka a tụrụ anya ya, arụmọrụ catalytic ahụ weghachiri nke ọma, ebe voltaji sel na-ebelata nke ukwuu ruo uru mbụ (site na 2.09 ruo 1.71 V) wee mụbaa ntakịrị n'ime awa 12 sochirinụ nke electrolysis (site na 1.71 ruo 1.79 V, mmụba nke 5%; Foto 6e).
N'ozuzu, anyị nwere ike nweta nkwụsi ike mmepụta AA awa 60 na-aga n'ihu na njupụta ugbu a nke 200 mA cm−2, nke na-egosi na a na-elekọta FE na voltaji sel nke AA nke ọma. Anyị nwalekwara njupụta ugbu a dị elu nke 300 mA cm−2 wee nweta nkwụsi ike zuru oke nke awa 58, na-edochi AEM na nke ọhụrụ mgbe awa 46 gachara. Ọmụmụ ihe ndị dị n'elu na-egosi nkwụsi ike nke ihe mkpali ahụ ma na-egosi nke ọma mkpa ọ dị maka mmepe AEM ndị dị elu n'ọdịnihu iji melite nkwụsi ike ogologo oge nke MEA maka mmepụta AA na-aga n'ihu na njupụta ugbu a kachasị mma n'ụlọ ọrụ.
Dabere na arụmọrụ nke MEA anyị, anyị tụrụ aro usoro mmepụta AA zuru oke gụnyere nri substrate, electrolysis, neutralization, na nkewa nkeji (Foto mgbakwunye 37). E mere nyocha arụmọrụ mbụ iji nyochaa ohere akụ na ụba nke sistemụ ahụ site na iji ụdị mmepụta alkaline electrocatalytic carboxylate 55. N'okwu a, ọnụ ahịa gụnyere isi obodo, ọrụ, na ihe (Foto 7a na Foto mgbakwunye 38), ego enwetara na-abịa site na mmepụta AA na H2. Nsonaazụ TEA na-egosi na n'okpuru ọnọdụ ọrụ anyị (njupụta ugbu a 300 mA cm-2, voltaji sel 1.76 V, FE 82%), mkpokọta ọnụ ahịa na ego enwetara bụ US$2429 na US$2564, n'otu n'otu, na-aghọ uru net nke US$135 kwa tọn nke AA emepụtara (lee Ihe Ntinye 9 maka nkọwa ndị ọzọ).
a Ọnụ ego zuru oke nke usoro elektrọnik AA n'okpuru ọnọdụ ikpe ntọala yana FE nke 82%, njupụta ugbu a nke 300 mA cm−2, na voltaji sel nke 1.76 V. Nyocha mmetụta nke ọnụ ahịa atọ maka njupụta ugbu a b FE na c. Na nyocha mmetụta, naanị paramita ndị a mụrụ gbanwere ma e debere paramita ndị ọzọ dabere na ụdị TEA. d Mmetụta nke njupụta FE dị iche iche na njupụta ugbu a na uru nke electrosynthesis AA na uru site na iji Ni(OH)2-NS na NiV-LDH-NS, na-eche na a na-edebe voltaji sel na 1.76 V. E nyere data ntinye maka a–d na faịlụ data raw.
Dabere na echiche a, anyị nyochakwuru mmetụta nke FE na njupụta ugbu a na uru nke electrosynthesis AA. Anyị chọpụtara na uru ahụ dị oke njọ na FE nke AA, ebe ọ bụ na mbelata na FE na-eduga na mmụba dị ukwuu na ọnụ ahịa ọrụ, si otú a na-amụba ọnụ ahịa zuru oke (Foto 7b). Banyere njupụta ugbu a, njupụta ugbu a dị elu (>200 mA cm-2) na-enyere aka belata ọnụ ahịa isi obodo na ọnụ ahịa owuwu ụlọ, ọkachasị site na ibelata mpaghara sel electrolytic, si otú a na-enye aka na mmụba na uru (Foto 7c). Ma e jiri ya tụnyere njupụta ugbu a, FE nwere mmetụta dị ukwuu na uru. Site n'ịkọwa mmetụta nke FE na njupụta ugbu a na uru, anyị na-ahụ nke ọma mkpa ọ dị iru FE dị elu (>60%) na njupụta ugbu a dị mkpa maka ụlọ ọrụ (>200 mA cm-2) iji hụ na uru dị. N'ihi nnukwu uru FE nke AA, sistemụ mmeghachi omume na NiV-LDH-NS dị ka ihe na-akpali akpali ka dị mma na oke nke 100-500 mA cm−2 (pentagram ntụpọ; Foto 7d). Agbanyeghị, maka Ni(OH)2-NS, mbelata FE na njupụta ọkụ eletrik dị elu (>200 mA cm−2) butere nsonaazụ na-adịghị mma (gburugburu; Foto 7d), na-egosipụta mkpa nke ihe na-akpali akpali nwere FE dị elu na njupụta ọkụ eletrik dị elu.
Na mgbakwunye na mkpa nke ihe ndị na-akpali akpali n'ibelata ọnụ ahịa isi obodo na ọrụ, nyocha TEA anyị na-egosi na uru nwere ike imeziwanye n'ụzọ abụọ. Nke mbụ bụ ire potassium sulfate (K2SO4) n'ahịa dịka ihe si na ya pụta, mana enwere ike inweta ego nke US $828/t AA-1 (Ndetu mgbakwunye 9). Nke abụọ bụ imeziwanye teknụzụ nhazi, gụnyere imegharị ihe ma ọ bụ mmepe nke teknụzụ nkewa AA dị ọnụ ala karịa (ihe ndị ọzọ maka nkeji neutralization na nkewa). Usoro neutralization acid-base ejiri ugbu a nwere ike ibute nnukwu ọnụ ahịa ihe (nke bụ òkè kachasị na 85.3%), nke 94% sitere na cyclohexanone na KOH ($2069/t AA-1; Foto 7a), mana dịka ekwuru n'elu, usoro ahụ ka na-aba uru n'ozuzu ya. Anyị na-atụ aro na enwere ike ibelata ọnụ ahịa ihe onwunwe site na ụzọ ndị ka elu maka mgbake nke KOH na cyclohexanone na-anaghị emeghachi omume, dịka electrodialysis maka mgbake zuru oke nke KOH14 (atụmatụ ọnụ ahịa nke US $1073/t AA-1 site na electrodialysis; Ihe Ndekọ Mgbakwunye 9).
Na nchịkọta, anyị nwetara nnukwu arụmọrụ nke aluminom atom electrolysis na nnukwu njupụta ugbu a site n'itinye V n'ime nanosheets Ni(OH)2. N'okpuru oke ike nke 1.5–1.9 VRHE na nnukwu njupụta ugbu a nke 170 mA cm−2, AA FE na NiV-LDH-NS ruru 83–88%, ebe a na-ebelata OER nke ọma ruo 3%. Mgbanwe V kwalitere mbelata nke Ni2+ ruo Ni3+x ma mee ka adsorption nke cyclohexanone dịkwuo mma. Data nnwale na nke echiche na-egosi na nhazi ahụ kpaliri na-eme ka njupụta ugbu a maka oxidation cyclohexanone dịkwuo elu ma na-agbanwe RDS nke COR site na nhazigharị gaa na dehydrogenation nke gụnyere Cα − H scission, ebe adsorption ka mma nke cyclohexanone na-egbochi OER. Mmepe nke MEA nwetara mmepụta AA na-aga n'ihu na njupụta ugbu a nke ụlọ ọrụ nke 300 mA cm−2, arụmọrụ AA ndekọ nke 82%, na mmepụta nke 1536 μmol cm−2 h−1. Nnwale awa iri ise gosiri na NiV-LDH-NS nwere ezigbo nkwụsi ike ebe ọ nwere ike ịnọgide na-enwe AA FE dị elu na MEA (> 80% maka awa iri isii na 200 mA cm−2; > 70% maka awa iri ise na asatọ na 300 mA cm−2). E kwesịrị ịmara na ọ dị mkpa ịmepụta AEM ndị siri ike karị iji nweta nkwụsi ike ogologo oge na njupụta ugbu a kacha mma n'ụlọ ọrụ mmepụta ihe. Na mgbakwunye, TEA na-egosipụta uru akụ na ụba nke atụmatụ mmeghachi omume maka mmepụta AA na mkpa nke ihe mkpali arụmọrụ dị elu na teknụzụ nkewa dị elu iji belata ọnụ ahịa.