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Rage sinadarin carbon dioxide zuwa formic acid ta hanyar lantarki hanya ce mai kyau ta inganta amfani da carbon dioxide kuma tana da yuwuwar amfani da ita azaman hanyar adana hydrogen. A cikin wannan aikin, an ƙirƙiri tsarin haɗa electrode membrane sifili-rata don haɗa formic acid kai tsaye daga carbon dioxide. Babban ci gaban fasaha shine membrane na musayar cation mai ramuka, wanda, idan aka yi amfani da shi a cikin tsarin membrane na bipolar gaba, yana ba da damar canza formic acid da aka samar a mahaɗin membrane ta hanyar filin kwararar anodic a cikin yawan da bai kai 0.25 M ba. Ba tare da ƙarin abubuwan sandwich tsakanin anode da cathode ba, manufar tana nufin amfani da kayan batirin da aka riga aka ƙera da ƙira waɗanda aka saba amfani da su a cikin ƙwayoyin mai da hydrogen electrolysis, wanda ke ba da damar sauyawa cikin sauri zuwa haɓaka da kasuwanci. A cikin tantanin halitta mai girman cm2 25, tsarin membrane na musayar cation mai ramuka yana ba da inganci >75% na Faraday don formic acid a <2 V da 300 mA/cm2. Mafi mahimmanci, gwajin kwanciyar hankali na awanni 55 a 200 mA/cm2 ya nuna ingantaccen ingancin Faraday da ƙarfin lantarki na tantanin halitta. Ana amfani da nazarin tattalin arziki da fasaha don kwatanta hanyoyin cimma daidaiton farashi tare da hanyoyin samar da formic acid na yanzu.
An nuna cewa rage sinadarin carbon dioxide zuwa formic acid ta amfani da wutar lantarki mai sabuntawa yana rage farashin samarwa da kashi 75% idan aka kwatanta da hanyoyin amfani da man fetur na gargajiya. Kamar yadda aka nuna a cikin wallafe-wallafe2,3, formic acid yana da aikace-aikace iri-iri, daga ingantacciyar hanya mai araha da tattalin arziki ta adanawa da jigilar hydrogen zuwa wurin samar da abinci ga masana'antar sinadarai4,5 ko masana'antar biomass6. Har ma an gano Formic acid a matsayin wurin samar da abinci don canzawa zuwa tsaka-tsakin man fetur mai dorewa ta amfani da injiniyan metabolism7,8. Tare da haɓaka tattalin arzikin formic acid1,9, ayyukan bincike da yawa sun mayar da hankali kan inganta zaɓin catalyst10,11,12,13,14,15,16. Duk da haka, ƙoƙari da yawa suna ci gaba da mai da hankali kan ƙananan ƙwayoyin H ko ƙwayoyin ruwa masu gudana waɗanda ke aiki a ƙarancin yawan yanzu (<50 mA/cm2). Don rage farashi, cimma kasuwanci da kuma ƙara yawan shiga kasuwa daga baya, dole ne a yi rage yawan carbon dioxide na lantarki (CO2R) a yawan wutar lantarki mai yawa (≥200 mA/cm2) da kuma ingancin Faraday (FE)17 yayin da ake ƙara yawan amfani da kayan aiki da kuma amfani da abubuwan da ke cikin batir daga fasahar ƙwayoyin mai da kuma electrolysis na ruwa suna ba da damar na'urorin CO2R su yi amfani da tattalin arziki na sikelin18. Bugu da ƙari, don ƙara yawan amfani da samarwa da kuma guje wa ƙarin sarrafawa, ya kamata a yi amfani da formic acid a matsayin samfurin ƙarshe maimakon gishirin da aka samar19.
A wannan hanyar, an yi ƙoƙarin da aka yi kwanan nan don haɓaka na'urorin watsa gas na CO2R formate/formic acid (GDE) masu dacewa da masana'antu. Cikakken bita da Fernandez-Caso et al.20 suka yi ya taƙaita duk tsarin ƙwayoyin lantarki don ci gaba da rage CO2 zuwa formic acid/formate. Gabaɗaya, duk tsare-tsaren da ake da su za a iya raba su zuwa manyan rukuni uku: 1. Catholytes mai gudana ta hanyar kwarara19,21,22,23,24,25,26,27, 2. Membrane ɗaya (membrane musayar cation (CEM)28 ko membrane musayar anion (AEM)29 da 3. Tsarin Sandwich15,30,31,32. An nuna sassa masu sauƙi na waɗannan tsare-tsaren a cikin Hoto na 1a. Don tsarin kwarara na catholyte, an ƙirƙiri ɗakin electrolyte tsakanin membrane da cathode na GDE. Ana amfani da catholyte mai gudana ta hanyar kwarara don ƙirƙirar tashoshin ion a cikin layin cathode na catalyst33, kodayake ana muhawara kan buƙatarta ta sarrafa zaɓin tsari34. Duk da haka, Chen et al sun yi amfani da wannan tsari. Ta amfani da cathode SnO2 akan wani abu mai carbon tare da kauri na catholyte mai 1.27 mm, har zuwa 90% FE 35 a 500 mA/cm2. An cimma haɗin catholyte mai kauri Layer da kuma membrane mai juye-juye (BPM) wanda ke iyakance canja wurin ion yana samar da ƙarfin lantarki na aiki na 6 V da kuma ingancin kuzari na 15%. Don inganta ingancin makamashi, Li et al., ta amfani da tsarin CEM guda ɗaya, sun cimma FE 29 na 93.3% a yawan ƙarfin lantarki na 51.7 mA/cm2. Diaz-Sainz et al.28 sun yi amfani da matse matattara tare da membrane CEM guda ɗaya a yawan halin yanzu na 45 mA/cm2. Duk da haka, duk hanyoyin suna samar da tsari maimakon samfurin da aka fi so, formic acid. Baya ga ƙarin buƙatun sarrafawa, a cikin saitunan CEM, tsare-tsare kamar KCOOH na iya taruwa cikin sauri a cikin GDE da filin kwarara, wanda ke haifar da ƙuntatawa na sufuri da gazawar ƙwayoyin halitta daga ƙarshe.
Kwatanta manyan CO2R guda uku da tsarin na'urorin canza sinadari na tsari/formic acid da kuma tsarin da aka gabatar a cikin wannan binciken. b Kwatanta jimillar yawan samar da sinadari na yanzu da tsari/formic acid don tsarin catholyte, tsarin sanwici, tsarin CEM guda ɗaya a cikin wallafe-wallafen (wanda aka nuna a cikin Tebur na Ƙarin S1) da aikinmu. Alamun buɗewa suna nuna samar da sinadari na tsari, kuma alamun ƙarfi suna nuna samar da sinadari na formic acid. *Saitin da aka nuna ta amfani da hydrogen a anode. c Tsarin MEA mai sifili ta amfani da membrane mai haɗaka tare da Layer ɗin musayar cation mai ramuka wanda ke aiki a yanayin bias na gaba.
Domin hana samuwar tsari, Proietto et al. 32 sun yi amfani da tsarin matse matattara mara rarrabuwa wanda ruwan da aka cire ion ya ratsa ta cikin layin. Tsarin zai iya cimma >70% CE a cikin kewayon yawan da ake da shi na yanzu na 50–80 mA/cm2. Hakazalika, Yang et al. 14 sun ba da shawarar amfani da wani Layer mai ƙarfi na electrolyte tsakanin CEM da AEM don haɓaka samuwar formic acid. Yang et al.31,36 sun sami 91.3% FE a cikin tantanin halitta mai girman cm2 5 a 200 mA/cm2, suna samar da maganin formic acid mai girman wt 6.35%. Xia et al. Ta amfani da irin wannan tsari, an sami nasarar canza carbon dioxide (CO2) zuwa formic acid FE 83% a 200 mA/cm2, kuma an gwada juriyar tsarin na tsawon awanni 100 da mintuna 30. Duk da cewa ƙananan sakamako suna da kyau, ƙaruwar farashi da sarkakiyar resins ɗin musayar ion mai ramuka suna sa ya yi wuya a daidaita tsarin layukan da suka haɗu zuwa manyan tsarin (misali, 1000 cm2).
Domin ganin tasirin tsare-tsare daban-daban, mun tsara samar da nau'in acid/formic a kowace kWh ga dukkan tsarin da aka ambata a baya kuma muka zana su a cikin Hoto na 1b. A bayyane yake a nan cewa duk wani tsarin da ke ɗauke da catholyte ko interlayer zai kai kololuwar aikinsa a ƙarancin yawan wutar lantarki kuma ya lalace a mafi yawan yawan wutar lantarki, inda iyakar ohmic na iya ƙayyade ƙarfin tantanin halitta. Bugu da ƙari, kodayake tsarin CEM mai amfani da makamashi yana samar da mafi girman yawan sinadarin molar formic a kowace kWh, tarin gishiri na iya haifar da raguwar aiki cikin sauri a yawan wutar lantarki mai yawa.
Domin rage yanayin gazawar da aka tattauna a baya, mun ƙirƙiri wani taro na membrane electrode assembly (MEA) wanda ke ɗauke da BPM mai haɗaka gaba tare da membrane mai huda cation exchange membrane (PCEM). An nuna tsarin a Hoto na 1c. An shigar da hydrogen (H2) cikin anode don samar da protons ta hanyar hydrogen oxidation reaction (HOR). An shigar da Layer na PCEM cikin tsarin BPM don ba da damar ions ɗin da aka samar a cathode su ratsa ta AEM, a haɗa su da protons don samar da formic acid a mahaɗin BPM da ramukan interstitial na CEM, sannan a fita ta hanyar GDE anode da filin kwarara. . Ta amfani da wannan tsari, mun cimma >75% FE na formic acid a <2 V da 300 mA/cm2 don yankin tantanin halitta 25 cm2. Mafi mahimmanci, ƙirar tana amfani da abubuwan da ake samu a kasuwa da gine-ginen kayan aiki don tsire-tsire na man fetur da electrolysis na ruwa, wanda ke ba da damar saurin girma. Tsarin Catholyte ya ƙunshi ɗakunan kwararar catholyte wanda zai iya haifar da rashin daidaiton matsin lamba tsakanin matakan iskar gas da ruwa, musamman a cikin manyan tsare-tsaren tantanin halitta. Ga tsarin sandwich mai ramuka masu kwararar ruwa, ana buƙatar ƙoƙari mai yawa don inganta matsakaicin rami don rage raguwar matsin lamba da tarin carbon dioxide a cikin matsakaicin rami. Duk waɗannan biyun na iya haifar da katsewar sadarwa ta salula. Hakanan yana da wuya a samar da yadudduka masu siririn rami masu tsayi a babban sikelin. Sabanin haka, sabon tsari da aka gabatar shine tsarin MEA mai sifili wanda ba ya ƙunshi ɗakin kwarara ko matakin tsakiya. Idan aka kwatanta da sauran ƙwayoyin lantarki da ke akwai, tsarin da aka gabatar ya keɓance saboda yana ba da damar haɗa kai tsaye na formic acid a cikin tsarin daidaitawa mai araha, mai amfani da makamashi, kuma mai sifili.
Don danne juyin halittar hydrogen, manyan ƙoƙarin rage CO2 sun yi amfani da tsarin membrane na MEA da AEM tare da manyan electrolytes masu yawan molar (misali, 1-10 M KOH) don ƙirƙirar yanayin alkaline a cathode (kamar yadda aka nuna a Hoto na 2a). A cikin waɗannan tsare-tsare, ions ɗin tsari da aka samar a cathode suna ratsa membrane a matsayin nau'in caji mara kyau, sannan aka samar da KCOOH kuma ya fita daga tsarin ta hanyar rafin anodic KOH. Kodayake da farko an sami kyakkyawan yanayin FE da ƙarfin tantanin halitta kamar yadda aka nuna a Hoto na 2b, gwajin kwanciyar hankali ya haifar da raguwar FE na kusan 30% cikin awanni 10 kacal (Hoto na S1a–c). Ya kamata a lura cewa amfani da anolyte na 1 M KOH yana da mahimmanci don rage yawan ƙarfin anodic a cikin tsarin amsawar juyin halittar oxygen na alkaline (OER)37 da cimma damar ion a cikin cathode catalyst bed33. Lokacin da aka rage yawan sinadarin anolyte zuwa 0.1 M KOH, ƙarfin ƙwayoyin halitta da kuma iskar shaka ta formic acid (asarar formic acid) suna ƙaruwa (Hoto na S1d), wanda ke nuna cinikin sifili. An tantance matakin iskar shaka ta format ta amfani da ma'aunin taro na gaba ɗaya; don ƙarin bayani, duba sashen "Hanyoyi". An kuma yi nazarin aikin ta amfani da tsarin membrane na MEA da CEM guda ɗaya, kuma an nuna sakamakon a Hoto na S1f,g. Tsarin FE da aka tattara daga cathode ya kasance >60% a 200 mA/cm2 a farkon gwajin, amma ya lalace cikin sauri cikin awanni biyu saboda tarin gishirin cathode da aka tattauna a baya (Hoto na S11).
Tsarin MEA mai rata sifili tare da CO2R a cathode, amsawar hydrogen oxidation (HOR) ko OER a anode, da kuma membrane ɗaya na AEM a tsakanin. b FE da ƙarfin lantarki na tantanin halitta don wannan tsari tare da 1 M KOH da OER suna gudana a anode. Sandunan kuskure suna wakiltar daidaitaccen karkacewar ma'auni guda uku daban-daban. a cikin FE da ƙarfin lantarki na tantanin halitta tare da H2 da HOR a anode. Ana amfani da launuka daban-daban don bambance samar da formate da formic acid. d Tsarin zane na MEA tare da BPM an canza shi gaba a tsakiya. FE da ƙarfin lantarki na baturi idan aka kwatanta da lokaci a 200 mA/cm2 ta amfani da wannan tsari. f Hoton giciye na BPM MEA mai son gaba bayan ɗan gajeren gwaji.
Domin samar da formic acid, ana samar da hydrogen zuwa ga mai kara kuzari na Pt-on-carbon (Pt/C) a anode. Kamar yadda aka nuna a Hoto na 2d, an riga an binciki wani proton mai samar da BPM mai son gaba a anode don cimma samar da formic acid. Na'urar daidaita BPM ta gaza bayan mintuna 40 na aiki a yanayin zafi na 200 mA/cm2, tare da karuwar wutar lantarki fiye da 5 V (Hoto na 2e). Bayan gwaji, an lura da bayyanannen rarrabuwa a yanayin zafi na CEM/AEM. Bayan tsari, anions kamar carbonate, bicarbonate da hydroxide suma suna iya ratsawa ta membrane na AEM kuma su yi aiki da protons a yanayin zafi na CEM/AEM don samar da iskar gas da ruwa mai tsafta, wanda hakan ke haifar da raguwar BPM (Hoto na 2f) da , wanda a ƙarshe ke haifar da gazawar ƙwayoyin halitta.
Dangane da tsarin aiki da gazawar tsarin da ke sama, an gabatar da sabon tsarin MEA kamar yadda aka nuna a Hoto na 1c kuma an yi cikakken bayani a Hoto na 3a38. A nan, layin PCEM yana samar da hanyar ƙaura na formic acid da anions daga hanyar haɗin CEM/AEM, ta haka ne rage tarin abu. A lokaci guda, hanyar haɗin PCEM tana jagorantar formic acid zuwa cikin matsakaicin yaɗuwa da filin kwarara, yana rage yuwuwar iskar oxygen ta formic acid. Sakamakon rarrabuwar ra'ayi ta amfani da AEMs masu kauri na 80, 40 da 25 mm an nuna su a Hoto na 3b. Kamar yadda aka zata, kodayake ƙarfin ƙwayar halitta gabaɗaya yana ƙaruwa tare da ƙaruwar kauri ta AEM, amfani da AEM mai kauri yana hana yaɗuwar formic acid baya, ta haka ne ƙara yawan pH na cathode da rage samar da H2 (Hoto na 3c–e).
Misali na tsarin MEA tare da AEM da CEM mai rami da kuma hanyoyin jigilar formic acid daban-daban. b Ƙarfin tantanin halitta a yawan ƙarfin yanzu daban-daban da kauri daban-daban na AEM. a cikin EE a yawan ƙarfin yanzu daban-daban tare da kauri na AEM na 80 μm (d) 40 μm, e) 25 μm. Sandunan kuskure suna wakiltar karkacewar da aka auna daga samfura guda uku daban-daban. f Sakamakon kwaikwayo na yawan formic acid da ƙimar pH a hanyar sadarwa ta CEM/AEM a kauri daban-daban na AEM. f PC da pH a cikin layin cathode na mai kara kuzari tare da kauri na fim ɗin AEM daban-daban. g Rarraba girma biyu na yawan formic acid tare da hanyar sadarwa ta CEM/AEM da huda.
Siffa ta S2 ta nuna rarrabawar yawan sinadarin formic acid da pH a fadin kauri na MEA ta amfani da samfurin Poisson-Nernst-Planck finite element. Ba abin mamaki ba ne cewa an lura da mafi girman yawan sinadarin formic acid, 0.23 mol/L, a mahaɗin CEM/AEM, tunda an samar da formic acid a wannan mahaɗin. Yawan sinadarin formic acid ta hanyar AEM yana raguwa da sauri yayin da kauri na AEM ke ƙaruwa, yana nuna ƙarin juriya ga canja wurin taro da ƙarancin kwararar formic acid saboda yaɗuwar baya. Sifofi na 3 f da g suna nuna ƙimar pH da formic acid a cikin gadon cathode mai haifar da yaɗuwar baya da rarrabawar girma biyu na yawan sinadarin formic acid, bi da bi. Mafi ƙanƙantar membrane na AEM, mafi girman yawan sinadarin formic acid kusa da cathode, kuma pH na cathode ya zama acidic. Saboda haka, kodayake membranes na AEM masu kauri suna haifar da asarar ohmic mafi girma, suna da mahimmanci don hana yaɗuwar formic acid zuwa cathode da haɓaka tsarkin tsarin FE formic acid. A ƙarshe, ƙara kauri na AEM zuwa 80 μm ya haifar da FE >75% ga formic acid a <2 V da 300 mA/cm2 ga yankin ƙwayoyin halitta na 25 cm2.
Domin gwada daidaiton wannan tsarin PECM, an kiyaye wutar lantarki ta batirin a 200 mA/cm2 na tsawon awanni 55. An nuna sakamakon gaba ɗaya a Hoto na 4, tare da sakamakon awanni 3 na farko da aka nuna a Hoto na S3. Lokacin amfani da mai kara kuzari na anodic na Pt/C, ƙarfin tantanin halitta ya ƙaru sosai a cikin mintuna 30 na farko (Hoto na S3a). A tsawon lokaci, ƙarfin tantanin halitta ya kasance kusan iri ɗaya, yana samar da ƙimar lalacewa ta 0.6 mV/h (Hoto na 4a). A farkon gwajin, PV na formic acid da aka tattara a anode shine 76.5% kuma PV na hydrogen da aka tattara a cathode shine 19.2%. Bayan awa ta farko na gwaji, hydrogen FE ya ragu zuwa 13.8%, wanda ke nuna ingantaccen zaɓin tsari. Duk da haka, ƙimar iskar shaka ta formic acid a cikin tsarin ta ragu zuwa 62.7% cikin awa 1, kuma ƙimar iskar shaka ta anodic formic acid ta ƙaru daga kusan sifili a farkon gwajin zuwa 17.0%. Daga baya, FE na H2, CO, formic acid da kuma ƙimar iskar shaka ta anodic acid ta kasance cikin kwanciyar hankali a lokacin gwajin. Ƙarawar iskar shaka ta formic acid a cikin awa ɗaya na iya faruwa ne saboda tarin formic acid a mahaɗin PCEM/AEM. Yayin da yawan iskar shaka ta formic acid ke ƙaruwa, ba wai kawai yana fita ta hanyar huda membrane ba, har ma yana yaɗuwa ta cikin FEM ɗin kanta kuma yana shiga layin anode na Pt/C. Tunda formic acid ruwa ne a 60°C, tarinsa na iya haifar da matsalolin canja wurin taro kuma yana haifar da fifita iskar shaka fiye da hydrogen.
Ƙarfin wutar lantarki na tantanin halitta idan aka kwatanta da lokaci (200 mA/cm2, 60 °C). Wannan na'urar tana nuna hoton na'urar hangen nesa ta MEA tare da ramin EM. Ma'aunin ma'auni: 300 µm. b Tsarkakakken PE da formic acid a matsayin aikin lokaci a 200 mA/cm2 ta amfani da anode na Pt/C.
An gano yanayin samfuran a farkon gwaji (BOT) yayin shiri da kuma ƙarshen gwaji (EOT) bayan awanni 55 na gwajin kwanciyar hankali ta amfani da nano-X-ray computed tomography (nano-CT), kamar yadda aka nuna a Hoto na 5 a. Samfurin EOT yana da girman barbashi mai girma tare da diamita na 1207 nm idan aka kwatanta da 930 nm na BOT. Hotunan duba electron mai ɗaukar hoto mai zurfi (HAADF-STEM) da sakamakon X-ray mai yaɗuwa ta makamashi (EDS) an nuna su a Hoto na 5b. Yayin da Layer catalyst na BOT ya ƙunshi mafi yawan ƙananan barbashi masu ƙara kuzari da kuma wasu manyan agglomerates, a matakin EOT za a iya raba Layer catalyst zuwa yankuna biyu daban-daban: ɗaya tare da manyan barbashi masu ƙarfi da ɗayan kuma tare da yankuna masu rami. Adadin ƙananan barbashi. Hoton EDS ya nuna cewa manyan barbashi masu ƙarfi suna da wadataccen Bi, wataƙila ƙarfe Bi, kuma yankunan da ke da rami suna da wadataccen oxygen. Lokacin da aka yi amfani da tantanin halitta a 200 mA/cm2, mummunan ƙarfin cathode zai haifar da raguwar Bi2O3, kamar yadda sakamakon in situ X-ray absorption spectroscopy da aka tattauna a ƙasa ya nuna. Sakamakon taswirar HAADF-STEM da EDS sun nuna cewa Bi2O3 yana fuskantar tsarin ragewa, wanda ke haifar da asarar iskar oxygen da haɗuwa zuwa manyan ƙwayoyin ƙarfe. Tsarin diffraction na X-ray na cathodes na BOT da EOT sun tabbatar da fassarar bayanan EDS (Hoto na 5c): an gano Bi2O3 mai lu'ulu'u ne kawai a cikin cathode na BOT, kuma an sami bimetal mai lu'ulu'u a cikin cathode na EOT. Don fahimtar tasirin ƙarfin cathode akan yanayin iskar shaka na cathode na Bi2O3, an canza zafin jiki daga ƙarfin da'ira mai buɗewa (+0.3 V vs RHE) zuwa -1.5 V (vs RHE). An lura cewa matakin Bi2O3 ya fara raguwa a -0.85 V idan aka kwatanta da RHE, kuma raguwar ƙarfin layin fari a yankin gefen bakan yana nuna cewa an rage ƙarfe Bi zuwa 90% na RHE a -1.1. V akan RHE (Hoto na 5d). Ko da menene tsarin, zaɓin tsari gaba ɗaya a cathode ba shi da canji, kamar yadda aka fahimta daga H2 da CO FE da samuwar formic acid, duk da manyan canje-canje a cikin yanayin cathode, yanayin iskar shaka mai haɓaka, da tsarin microcrystalline.
Tsarin girma uku na layin mai kara kuzari da rarraba barbashi masu kara kuzari da aka samu ta amfani da nano-X-ray CT. Sandar sikelin: 10 µm. b Sama na 2: Hotunan HAADF-STEM na yadudduka na cathode na BOT da EOT masu kara kuzari. Sandar sikelin: 1 µm. Kasa na 2: An kara girman hotunan HADF-STEM da EDX na layin cathode na mai kara kuzari na EOT. Sandar sikelin: 100 nm. c Tsarin watsawar X-ray na samfuran BOT da EOT. d In situ X-ray sha spectra na electrode Bi2O3 a cikin 0.1 M KOH a matsayin aikin yuwuwar (0.8 V zuwa -1.5 V vs. RHE).
Domin tantance ainihin damar da ake da ita don inganta ingancin makamashi ta hanyar hana iskar shaka ta formic acid, an yi amfani da na'urar lantarki ta H2 don gano gudummawar asarar wutar lantarki39. A halin yanzu da yawa ƙasa da 500 mA/cm2, ƙarfin cathode ya kasance ƙasa da -1.25 V. An raba ƙarfin anodic zuwa manyan sassa biyu: yawan canjin wutar lantarki HOR da kuma yawan ƙarfin lantarki na ka'ida HOR 40 da aka annabta ta hanyar lissafin Bulter-Volmer da aka auna a baya, kuma sauran ɓangaren ya faru ne saboda iskar shaka ta formic acid. Saboda saurin amsawar amsawa idan aka kwatanta da HOR41, ƙaramin ƙimar amsawar iskar shaka ta formic acid a anode na iya haifar da ƙaruwa mai yawa a cikin ƙarfin anodic. Sakamakon ya nuna cewa cikakken hana iskar shaka ta formic acid anodic zai iya kawar da kusan ƙarfin lantarki na 500 mV.
Don gwada wannan kiyasin, an bambanta yawan kwararar ruwan da aka cire ionized (DI) a mashigar anode don rage yawan fitar da formic acid. Hotuna na 6b da c sun nuna FE, yawan formic acid, da ƙarfin tantanin halitta a matsayin aikin kwararar DI a anode a 200 mA/cm2. Yayin da yawan kwararar ruwan da aka cire ionized ya karu daga 3.3 mL/min zuwa 25 mL/min, yawan formic acid a anode ya ragu daga 0.27 mol/L zuwa 0.08 mol/L. A kwatanta, ta amfani da tsarin sandwich da Xia et al. 30 suka gabatar, an sami yawan formic acid na 1.8 mol/L a 200 mA/cm2. Rage yawan yana inganta FE gaba ɗaya na formic acid kuma yana rage FE na H2 yayin da cathode pH ya zama alkaline saboda raguwar yaduwar formic acid. Rage yawan sinadarin formic acid a matsakaicin kwararar DI shi ma ya kawar da iskar shaka ta formic acid, wanda hakan ke haifar da jimlar ƙarfin lantarki na tantanin halitta wanda bai kai 1.7 V ba a 200 mA/cm2. Zafin batirin kuma yana shafar aikin gabaɗaya, kuma an nuna sakamakon a cikin Hoto na S10. Duk da haka, tsarin PCEM na iya inganta ingantaccen makamashi sosai wajen hana iskar shaka ta formic acid, ko ta hanyar amfani da abubuwan kara kuzari na anodic tare da ingantaccen zaɓin hydrogen zuwa ga formic acid ko ta hanyar aikin na'ura.
a Rushewar ƙarfin lantarki ta sel ta amfani da na'urar lantarki ta H2 mai nuni ga sel wanda ke aiki a 60 °C, Pt/C anode da 80 µm AEM. b FE da yawan acid na formic da aka tattara a 200 mA/cm2 ta amfani da kwararar ruwa daban-daban na anodic deionized. c Lokacin da anode ya tattara formic acid a cikin tarin yawa daban-daban, ƙarfin tantanin halitta shine 200 mA/cm2. Sandunan kuskure suna wakiltar daidaitaccen karkacewar ma'auni guda uku daban-daban. d Mafi ƙarancin farashin siyarwa da aka raba ta hanyar aiki a cikin adadin kwararar ruwa na deionized daban-daban ta amfani da matsakaicin farashin wutar lantarki na masana'antu na US$0.068/kWh da US$4.5/kg hydrogen. (*: Ana ɗaukar cewa mafi ƙarancin yanayin iskar shaka na formic acid a anode shine 10 M FA, matsakaicin farashin wutar lantarki na masana'antu na ƙasa shine $0.068/kWh, kuma hydrogen shine $4.5/kg. **: Ana ɗaukar mafi ƙarancin yanayin iskar shaka na formic acid. Yawan FA a anode shine 1.3 M anode, farashin wutar lantarki da ake tsammanin nan gaba shine $0.03/kWh, kuma layin da aka nuna yana wakiltar farashin kasuwa na 85 wt% FA.
An gudanar da bincike kan tattalin arziki da fasaha (TEA) don samun mafi ƙarancin farashin siyarwa na haɗakar mai a ƙarƙashin yanayi daban-daban na aiki, kamar yadda aka nuna a Hoto na 5d. Ana iya samun hanyoyi da bayanan asali na TEA a cikin SI. Lokacin da yawan LC a cikin hayakin anode ya fi girma, duk da yawan ƙarfin tantanin halitta, jimlar farashin haɗakar mai yana raguwa saboda raguwar farashin rabuwa. Idan za a iya rage iskar oxidation na anodic na formic acid ta hanyar haɓaka catalyst ko fasahar lantarki, haɗakar ƙarancin ƙarfin tantanin halitta (1.66 V) da yawan FA a cikin fitar da mai (10 M) zai rage farashin samar da lantarki na FA zuwa dala 0.74 na Amurka/kg (bisa ga wutar lantarki). farashin) $0.068/kWh da $4.5/kg hydrogen42. Bugu da ƙari, idan aka haɗa shi da hasashen farashin wutar lantarki mai sabuntawa na $0.03/kWh da hydrogen na $2.3/kg, an rage burin FA na ruwan sharar gida zuwa miliyan 1.3, wanda ke haifar da hasashen farashin samarwa na ƙarshe shine US $0.66/kg43. Wannan yayi daidai da farashin kasuwa na yanzu. Don haka, ƙoƙarin da aka yi nan gaba kan kayan lantarki da tsare-tsare na iya ƙara rage anodization yayin da ake ba da damar aiki a ƙananan ƙarfin lantarki don samar da mafi girman yawan LC.
A taƙaice, mun yi nazari kan tsarin MEA da dama na rage CO2 zuwa formic acid kuma mun gabatar da tsarin da ke ɗauke da membrane mai kama da gaba-bipolar wanda ya haɗa da membrane mai ramin cation exchange membrane (PECM) don sauƙaƙe hanyar canja wurin taro na membrane don sakamakon formic acid. . Wannan tsari yana samar da >96% formic acid a yawan da ya kai 0.25 M (a ƙimar kwararar anode DI na 3.3 mL/min). A mafi girman ƙimar kwararar DI (25 mL/min), wannan tsari ya samar da yawan yanzu na >80% FE na 200 mA/cm2 a 1.7 V ta amfani da yankin tantanin halitta na 25 cm2. A matsakaicin ƙimar DI na anodic (10 mL/min), tsarin PECM ya kiyaye ƙarfin lantarki mai karko da matakan FE mai ƙarfi na formic acid na tsawon awanni 55 na gwaji a 200 mA/cm2. Babban kwanciyar hankali da zaɓin da aka samu ta hanyar masu haɓaka sinadarai da kayan membrane na polymeric da ake samu a kasuwa za a iya ƙara inganta su ta hanyar haɗa su da ingantattun masu haɓaka electrocatalysts. Aikin da za a yi nan gaba zai mayar da hankali kan daidaita yanayin aiki, zaɓin mai haɓaka sinadarin anode, da tsarin MEA don rage iskar oxygen ta formic acid, wanda ke haifar da ƙarin yawan fitar da iskar gas a ƙananan ƙarfin lantarki na tantanin halitta. Hanya mai sauƙi ta amfani da carbon dioxide don formic acid da aka gabatar a nan ta kawar da buƙatar ɗakunan anolyte da catholyte, abubuwan sandwich, da kayan aiki na musamman, ta haka ne za a ƙara ingancin makamashin tantanin halitta da rage sarkakiyar tsarin, wanda hakan zai sauƙaƙa haɓaka shi. Tsarin da aka gabatar yana samar da dandamali don haɓaka masana'antun canza CO2 masu amfani a nan gaba a fannin fasaha da tattalin arziki.
Sai dai idan an faɗi akasin haka, an yi amfani da duk kayan sinadarai da abubuwan narkewa kamar yadda aka karɓa. An sayi Bismuth oxide catalyst (Bi2O3, 80 nm) daga US Research Nanomaterials, Inc. IONOMR ne ya samar da foda polymer (AP1-CNN8-00-X). An sayi N-propanol (nPA) na Omnisolv® da ruwan ultrapure (18.2 Ω, Milli–Q® Advantage A10 na tsarkake ruwa) daga Millipore Sigma. Ana siyan methanol da acetone na ACS daga VWR Chemicals BDH® da Fisher Chemical, bi da bi. An haɗa foda polymer ɗin da cakuda acetone da methanol a cikin rabo na 1:1 ta nauyi don samun watsawar polymer tare da yawan 6.5 wt.%. Shirya tawada mai narkewa ta hanyar haɗa 20g Bi2O3, ruwan ultrapure, nPA da watsawar ionomer a cikin kwalbar 30ml. Abun da ke cikinsa ya ƙunshi kashi 30% na sinadarin catalyst, rabon taro na ionomer zuwa mai kara kuzari na 0.02 da kuma rabon taro na barasa zuwa ruwa na 2:3 (40 wt.% nPA). Kafin a haɗa, an ƙara 70g na kayan niƙa na Glen Mills 5mm zirconia a cikin cakuda. An sanya samfura a kan na'urar birgima ta kwalbar dijital ta Fisherbrand™ a 80 rpm na tsawon awanni 26. A bar tawada ta zauna na tsawon mintuna 20 kafin a shafa. An shafa tawada ta Bi2O3 a kan na'urar amfani da na'urar Qualtech ta atomatik (QPI-AFA6800) ta amfani da na'urar cika ramin dakin gwaje-gwaje mai girman 1/2″ x 16″ (RD Specialties - diamita mil 60) a 22°C. An shafa 5 mL na tawada mai kara kuzari a kan na'urar jigilar iskar gas ta carbon Sigraacet 39 BB mai girman inci 8 (ajiyar ƙwayoyin mai) ta hanyar ajiye sandar a matsakaicin gudu na 55 mm/sec. A mayar da waɗannan na'urorin lantarki masu rufi zuwa tanda a busar da su a zafin digiri 80 na Celsius. Tsarin rufe sandar da hotunan murfin GDE an nuna su a cikin Hotunan S4a da b. Wani kayan aiki na X-ray fluorescence (XRF) (Fischerscope® XDV-SDD, Fischer-Technolgy Inc. USA) ya tabbatar da cewa nauyin GDE mai rufi shine 3.0 mg Bi2O3/cm2.
Don tsarin membrane mai haɗaka wanda ya ƙunshi membrane na musayar anion (AEM) da kuma CEM mai huda, an yi amfani da Nafion NC700 (Chemours, Amurka) mai kauri na 15 µm a matsayin Layer na CEM. An fesa mai haɓaka anodic kai tsaye a kan FEM tare da rabon ionomer zuwa carbon na 0.83 da yankin rufewa na 25 cm2. An yi amfani da platinum mai tallafi tare da babban yanki na saman (50 wt.% Pt/C, TEC 10E50E, TANAKA mai daraja ƙarfe) tare da nauyin 0.25 mg Pt/cm2 a matsayin mai haɓaka anode. An yi amfani da Nafion D2020 (Ion Power, Amurka) a matsayin ionomer don Layer na mai haɓaka. Ana yin huda CEM ta hanyar yanke layuka masu layi ɗaya akan fim ɗin CEM a tazara ta 3mm. Cikakkun bayanai game da tsarin huda an nuna su a cikin Figures S12b da c. Ta amfani da na'urar daukar hoton X-ray, an tabbatar da cewa gibin ramin ramin ya kai 32.6 μm, kamar yadda aka nuna a Hoto na S12d da e. A lokacin haɗa ƙwayoyin halitta, an sanya wani membrane mai huda mai rufi da catalyst a kan takarda Toray mai girman 25 cm2 (5 wt% PTFE da aka yi wa magani, Fuel Cell Store, Amurka). An sanya membrane na AEM (PiperION, Versogen, Amurka) mai kauri na 25, 40 ko 80 μm a saman CEM sannan a kan cathode na GDE. An yanke membrane na AEM zuwa guda 7.5 × 7.5 cm don rufe dukkan filin kwararar kuma an jiƙa shi cikin ruwan potassium hydroxide na 1 M kafin a haɗa shi. Duk anode da cathode suna amfani da spacers na PTFE waɗanda suka isa su sami mafi kyawun matsi na GDE na 18%. Cikakkun bayanai game da tsarin haɗa batirin an nuna su a Hoto na S12a.
A lokacin gwaji, an kiyaye tantanin da aka haɗa a zafin 60 °C (30, 60, da 80 °C don nazarin dogaro da zafin jiki) tare da iskar hydrogen 0.8 L/min da aka kawo wa anode da L/min 2 na carbon dioxide da aka kawo wa cathode. An sanya ruwan iskar anodic da cathodic duka a yanayin zafi 100% da kuma matsin lamba na cathodic 259 kPa. A lokacin aiki, an haɗa ruwan iskar cathode da maganin M KOH 1 a matakin 2 mL/min don haɓaka amfani da gadon cathode da kuma isar da ionic. A haɗa ruwan iskar anode da ruwan da aka cire a matakin 10 ml/min don cire formic acid a anode. Cikakkun bayanai game da shigarwar na'urar da fitarwa an nuna su a Hoto na S5. Iskar gas ɗin shaye-shayen cathode ya ƙunshi CO2 kuma yana samar da CO2 da H2. Ana cire tururin ruwa ta hanyar na'urar sanyaya zafi (ƙarancin musayar zafi a 2°C). Za a tattara sauran iskar don nazarin lokacin gas. Haka kuma kwararar anode za ta ratsa ta cikin na'urar sanyaya iskar gas don raba ruwan da iskar gas. Za a tattara ruwan sharar a cikin kwalaben tsafta sannan a yi nazari ta amfani da chronometry na ruwa don auna sinadarin formic da aka samar. An yi gwaje-gwajen electrochemical ta amfani da Garmy potentiostat (lambar tunani 30K, Gamry, Amurka). Kafin a auna lanƙwasa polarization, an daidaita tantanin halitta sau 4 a cikin kewayon daga 0 zuwa 250 mA/cm2 ta amfani da voltammetry mai layi tare da ƙimar scan na 2.5 mA/cm2. An sami lanƙwasa polarization a cikin yanayin galvanostatic tare da tantanin halitta a riƙe a wani takamaiman yawan halin yanzu na mintuna 4 kafin a ɗauki iskar gas ta cathode da ruwan anolyte.
Muna amfani da na'urar lantarki mai amfani da hydrogen a cikin MEA don raba ƙarfin cathode da anodic. An nuna tsarin na'urar lantarki mai amfani da ita a cikin Hoto na S6a. An yi amfani da na'urar lantarki mai suna Nafion (Nafion 211, IonPower, Amurka) a matsayin gadar ionic don haɗa na'urar lantarki ta MEA da na'urar lantarki mai amfani da ita. An haɗa ƙarshen ɗaya na na'urar lantarki mai amfani da iskar gas mai girman cm2 (GDE) wanda aka ɗora da 0.25 mg Pt/cm2 (50 wt% Pt/C, TEC10E50E, TANAKA Precious Metals) wanda aka fesa a kan takardar carbon ta 29BC (Shagon Man Fetur, Amurka). Ana amfani da kayan aikin polyetheretherketone na musamman (PEEK) don rufe gas da kuma tabbatar da kyakkyawar hulɗa tsakanin na'urorin GDE da Nafion, da kuma haɗa na'urar lantarki mai amfani da ita zuwa kayan aikin na'urar lantarki. Ɗayan ƙarshen na'urar lantarki mai amfani da ita an haɗa ta da gefen da ke fitowa daga batirin CEM. Siffa ta S6b tana nuna ɓangaren giciye na na'urar aunawa da aka haɗa da MEA.
Bayan iskar gas mai fitar da hayaki ta ratsa na'urar raba iskar gas da ruwa, ana ɗaukar samfuran iskar gas daga cathode. An yi nazarin iskar gas da aka tattara aƙalla sau uku ta amfani da 4900 Micro GC (sife na kwayoyin halitta 10 μm, Agilent). An tattara samfuran a cikin jakunkunan samfurin gas na aluminum foil mai laushi da yawa Supel™ (Sigma-Aldrich) na wani takamaiman lokaci (daƙiƙa 30) kuma an saka su da hannu cikin microgas chromatograph cikin awanni biyu bayan an tattara su. An saita zafin allurar a 110°C. An raba Carbon monoxide (CO) da hydrogen (H2) a kan ginshiƙin MS5A mai zafi (105 °C) mai matsin lamba (28 psi) 10 m ta amfani da argon (Matheson Gas-Matheson Purity) a matsayin iskar gas mai ɗaukar kaya. Ana gano waɗannan haɗin ta amfani da Mai Gano Maɗaukakin Zafin Jiki (TCD) da aka gina a ciki. An nuna chromatograms na GC da lanƙwasa na daidaitawar CO da H2 a cikin Hoto na S7. An tattara samfuran ruwa mai suna formic acid daga anode na wani takamaiman lokaci (daƙiƙa 120) kuma an tace su ta amfani da matattarar sirinji na PTFE 0.22 μm zuwa cikin kwalba 2 mL. An yi nazarin samfuran ruwa a cikin kwalba ta amfani da tsarin Agilent 1260 Infinity II bioinert high-performance liquid chromatography (HPLC), inda aka allurar 20 μl na samfurin ta hanyar autosampler (G5668A) tare da matakin motsi na 4 mM sulfuric acid (H2SO4). ) a cikin ƙimar kwarara na 0.6 ml/min (famfon quaternary G5654A). An raba samfuran a kan wani mai zafi (35°C, tanda mai shafi G7116A) Aminex HPX-87H 300 × 7.8 mm (Bio-Rad) wanda aka riga aka sanya a kan ginshiƙin kariya na Micro-Guard Cation H. An gano Formic acid ta amfani da na'urar gano diode array detector (DAD). a cikin tsawon rai na 210 nm da kuma bandwidth na 4 nm. An nuna ma'aunin chromatogram na HPL da kuma ma'aunin daidaitaccen acid na formic acid a cikin Hoto na S7.
Ana ƙididdige samfuran iskar gas (CO da H2) FE ta amfani da lissafin da ke ƙasa, kuma ana ƙididdige jimillar moles na iskar gas ta amfani da daidaitaccen lissafin iskar gas:
Daga cikinsu: \({n}_{i}\): adadin electrons a cikin amsawar lantarki. \(F\): Madaidaitan Faraday. \({C}_{i}\): Yawan samfurin ruwa na HPLC. \(V\): girman samfurin ruwa da aka tattara a cikin wani ƙayyadadden lokaci t. \(j\): yawan halin yanzu. \(A\): Yankin Geometric na electrode (25 cm2). \(t\): lokacin ɗaukar samfur. \(P\): matsin lamba cikakke. \({x}_{i}\): Kashi na mole na iskar gas da GC ta ƙaddara. \(R\): madaidaitan iskar gas. \(T\): zafin jiki.
An auna yawan sinadarin anodic cations ta amfani da inductively coupled plasma atomic emission spectroscopy (ICP-OES). Cations ɗin da za su iya shiga ko yaɗuwa cikin anode sun haɗa da Ti, Pt, Bi da K. Banda K, duk sauran cations sun kasance ƙasa da iyakar ganowa. ions ɗin da ke cikin maganin suna barin anode ya haɗu da protons ko wasu cations. Saboda haka, ana iya ƙididdige tsarkin formic acid kamar haka
Samar da tsari/FA yana wakiltar adadin FA da ake samarwa a kowace kWh na wutar lantarki da ake amfani da ita ta amfani da takamaiman tsarin MEA, a cikin mol/kWh. Ana ƙididdige shi bisa ga yawan wutar lantarki, ƙarfin tantanin halitta da ingancin Faraday a ƙarƙashin takamaiman yanayin aiki.
Lissafa adadin formic acid da aka yi oxidized a anode bisa ga ma'aunin taro gaba ɗaya. Halaye uku masu fafatawa suna faruwa a cathode: juyin halittar hydrogen, rage CO2 zuwa CO, da rage CO2 zuwa formic acid. Saboda muna da tsarin oxidation na formic acid a Anton, ana iya raba formic acid FE zuwa sassa biyu: tarin formic acid da oxidation na formic acid. Ana iya rubuta ma'aunin taro gaba ɗaya kamar haka:
Mun yi amfani da GC don ƙididdige adadin formic acid, hydrogen, da CO da HPLC ta tattara. Ya kamata a lura cewa yawancin formic acid an tattara su ne daga anode ta amfani da saitin da aka nuna a cikin Ƙarin Hoto na S5. Adadin format da aka tattara daga ɗakin cathode ba shi da mahimmanci, kusan tsari biyu na girma ƙasa da haka, kuma ya kai ƙasa da 0.5% na jimlar adadin SC.
Tsarin jigilar kaya mai ci gaba da aka yi amfani da shi a nan ya dogara ne akan aikin da aka yi a baya akan irin waɗannan tsarin34. Ana amfani da tsarin haɗin gwiwa na lissafin Poisson-Nerst-Planck (PNP) don tantance yawan ruwa da ƙarfin lantarki a cikin matakan gudanarwa ta lantarki da ionic. An ba da cikakken bayani game da daidaitattun da ke ƙasa da yanayin samfurin a cikin SI.
Wannan tsarin yana ƙayyade yawan abubuwan ruwa guda takwas (\({{{{{\rm{C}}}}}}}}{{{{{\rm{O}}}}}}}_{2 \left ({{{{{\rm{aq}}}}}}\right)}\), \({{{{{{\rm{H}}}}}}}}^{+ }\ ), \ ({{{{{\rm{O}}}}}}}{{{{\rm{H}}}}}}}^{-}\), \({{{ {{ \rm{ HCO}}}}}}}_{3}^{-}\), \({{{{{\rm{CO}}}}}}_{3}^{ 2-} \ ),\ ({{{{\rm{HCOOH}}}}}}}\), \({{{{{{\rm{HCOO}}}}}}}}^{- }\) da \({{{ {{\rm{K}}}}}}^{+}\)), ƙarfin lantarki a cikin matakin gudanarwa na ionic (\({\phi }_{I}\ )) da kuma ƙarfin lantarki na anodic da cathodic. Ƙarfin lantarki a cikin matakai (\({\phi }_{A}\) da \({\phi }_{C}\) bi da bi). Madadin haka, ba a cimma ayyukan tsaka-tsaki na lantarki na gida ko rarraba caji ba, ana warware yankin cajin sarari kai tsaye ta amfani da lissafin Poisson; Wannan hanyar tana ba mu damar yin kwaikwayon tasirin tunkuɗa Donnan kai tsaye a mahaɗin CEM|AEM, CEM|Pore, da AEM|Pore. Bugu da ƙari, ana amfani da ka'idar lantarki mai ramuka (PET) don bayyana jigilar caji a cikin yadudduka na anodic da cathodic na mai kara kuzari. A gwargwadon ilimin marubutan, wannan aikin yana wakiltar aikace-aikacen farko na PET a cikin tsarin da ke da yankuna da yawa na cajin sarari.
An gwada samfuran GDE BOT da EOT cathode ta amfani da Zeiss Xradia 800 Ultra tare da tushen X-ray na 8.0 keV, yanayin sha da faɗin filin, da kuma haɗakar hoto1. An tattara hotuna 901 daga -90° zuwa 90° tare da lokacin fallasa na daƙiƙa 50. An sake ginawa ta amfani da matattarar hasashen baya tare da girman voxel na 64 nm. An gudanar da nazarin rarrabuwa da rarraba girman barbashi ta amfani da lambar da aka rubuta ta musamman.
Halayyar na'urar lantarki mai ƙananan ƙwayoyin cuta ta ƙunshi saka MEAs na gwaji a cikin resin epoxy don shirya rabuwa mai matuƙar siriri da wuka mai lu'u-lu'u. An yanke sashin giciye na kowane MEA zuwa kauri daga 50 zuwa 75 nm. An yi amfani da na'urar hangen nesa ta lantarki ta Talos F200X (Thermo Fisher Scientific) don duba na'urar hangen nesa ta lantarki mai watsawa (STEM) da kuma auna na'urar hangen nesa ta X-ray mai watsawa (EDS). Na'urar hangen nesa ta lantarki tana da tsarin EDS Super-X tare da na'urorin gano SDD guda 4 marasa tagogi kuma tana aiki a 200 kV.
An samo tsarin diffraction na foda X-ray (PXRD) akan na'urar auna hasken X-ray ta Bruker Advance D8 tare da hasken Ni-filtered Cu Kα wanda ke aiki a 40 kV da 40 mA. Matsakaicin sikanin yana daga 10° zuwa 60°, girman matakin shine 0.005°, kuma saurin samun bayanai shine daƙiƙa 1 a kowane mataki.
An auna bakan RAS a gefen Bi2O3 Bi L3 mai kara kuzari a matsayin aikin yuwuwar amfani da ƙwayar halitta da aka yi da gida. An shirya tawada mai kara kuzari ta Bi2O3 mai kara kuzari ta amfani da 26.1 mg na Bi2O3 da aka gauraya da maganin ionomer 156.3 μL (6.68%) sannan aka narkar da shi da 1 M KOH, ruwa (157 μL) da kuma isopropyl alcohol (104 μL) don samun tawada mai kara kuzari. Ma'aunin kara kuzari shine 0.4. An shafa tawada a kan zanen graphene a cikin wuraren murabba'i (10 × 4 mm) har sai nauyin kara kuzari na Bi2O3 ya kai 0.5 mg/cm2. Sauran zanen graphene an shafa shi da Kapton don ware waɗannan wurare daga electrolyte. An saka zanen graphene mai kara kuzari tsakanin PTFEs guda biyu kuma an manne shi da sukurori a jikin tantanin halitta (PEEK) da sukurori, Hoto na S8. Hg/HgO (1 M NaOH) ya yi aiki a matsayin lantarki mai tunani, kuma an yi amfani da takardar carbon a matsayin lantarki mai kara kuzari. An daidaita wutar lantarki ta Hg/HgO ta amfani da wayar platinum da aka nutsar a cikin hydrogen mai cike da 0.1 M KOH don canza duk ƙarfin da aka auna zuwa sikelin hydrogen electrode (RHE). An samo spectra na XRD ta hanyar sa ido kan yuwuwar lantarki mai aiki da takardar Bi2O3/graphene wanda aka nutsar a cikin 0.1 M KOH, wanda aka dumama shi zuwa 30 °C. Elektrolyt ɗin yana zagayawa a cikin baturi, tare da shigarwar electrolyte a ƙasan tantanin halitta da kuma hanyar fita a sama don tabbatar da cewa electrolyte ɗin ya haɗu da layin catalyst lokacin da kumfa ya fito. An yi amfani da CH Instruments 760e potentiostat don sarrafa yuwuwar lantarki mai aiki. Jerin yuwuwar shine yuwuwar da'ira mai buɗewa: -100, -200, -300, -400, -500, -800, -850, -900, -1000, -1100, -1500 da +700 mV dangane da RHE. An daidaita duk ƙarfin iR.
An yi gwajin X-ray edge (~13424 eV don ƙarfe na Bi) X-ray fine structure (XAFS) spectroscopy akan tashar 10-ID, Advanced Photon Source (APS), Argonne National Fluorescence Laboratory. National Model Measurement Laboratory. An yi amfani da monochromator mai lu'ulu'u biyu Si(111) wanda aka sanyaya da ruwa nitrogen don daidaita kuzarin X-ray, kuma an yi amfani da madubi mai rufi da rhodium don rage abubuwan da ke cikin jituwa. An bambanta kuzarin scan daga 13200 zuwa 14400 eV, kuma an auna hasken ta amfani da jerin diode na silicon PIN na 5 × 5 ba tare da matattara ko ramukan Soller ba. An daidaita kuzarin sifili na sifili na samfurin na biyu a 13271.90 eV ta gefen L2 na foil ɗin Pt. Saboda kauri na ƙwayar lantarki, ba zai yiwu a auna bakan ma'aunin tunani a lokaci guda ba. Saboda haka, canjin da aka ƙididdige na scan-to-scan a cikin makamashin X-ray na faruwa shine ±0.015 eV bisa ga ma'auni da aka maimaita a cikin gwajin. Kauri na layin Bi2O3 yana haifar da wani matakin sha da kansa na haske; electrodes suna riƙe da daidaitaccen yanayin dangane da hasken abin da ya faru da na'urar ganowa, suna sa duk scans ɗin su yi kama da juna. An yi amfani da bakan XAFS na kusa-filin don tantance yanayin oxidation da sifar sinadarai na bismuth ta hanyar kwatantawa da yankin XANES na ma'aunin Bi da Bi2O3 ta amfani da algorithm na haɗa layi na software na Athena (sigar 0.9.26). ta lambar IFEFFIT 44.
Bayanan da ke goyon bayan alkaluman da ke cikin wannan labarin da sauran sakamakon wannan binciken suna samuwa daga marubucin da ya dace bisa buƙata mai ma'ana.
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