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Uburyo bwiza, buhendutse kandi burambye bwo kugabanya umwuka wa ogisijeni (ORR) amashanyarazi afite akamaro kanini kuri bateri ya kabiri ya Zn-air.Igikorwa cya ORR cya oxyde imwe ivanze kandi ivanze na carbone electrocatalysis yakozwe hakoreshejwe ibipimo bizunguruka disiki ya electrode (RDE), imisozi ya Tafel, hamwe na Kutetsky-Levich.Byagaragaye ko guhuza MnOx na XC-72R byerekana ibikorwa bya PBP bihamye kandi bihamye, kugeza kuri cm 100 mA cm - 2.Imikorere ya electrode yatoranijwe ya ORR hamwe na electrode yabanje gutezimbere (OER) electrode noneho byageragejwe muri bateri ya kabiri ya zinc-air ya batiri yubatswe muburyo bwa electrode eshatu, kandi ubucucike buriho, ubukana bwa electrolyte, ubushyuhe, ubuziranenge bwa ogisijeni byari yageragejwe.Ibiranga ORR na OERelectrode.Hanyuma, hasuzumwe uburebure bwa sisitemu ya kabiri ya zinc-air, hasuzumwa ingufu zingana na 58-61% kuri 20 mA cm-2 muri 4 M NaOH + 0.3 M ZnO kuri 333 K mumasaha 40.
Batteri yumwuka hamwe na electrode ya ogisijeni ifatwa nka sisitemu ishimishije cyane kuko ibikoresho byamashanyarazi ya ogisijeni electrode irashobora kuboneka byoroshye mukirere gikikije kandi ntibisaba kubika1.Ibi byoroshya igishushanyo cya sisitemu yemerera ogisijeni electrode ifite ubushobozi butagira imipaka, bityo bikongerera ingufu za sisitemu.Kubwibyo, bateri yumwuka-mwuka ukoresheje ibikoresho bya anode nka lithium, aluminium, fer, zinc, na magnesium byagaragaye kubera ubushobozi bwihariye bwihariye.Muri byo, bateri zo mu kirere zinc zirashobora rwose guhaza isoko ryibiciro, umutekano, hamwe n’ibidukikije, kubera ko zinc ifite ibintu byinshi byifuzwa nkibikoresho bya anode, nko guhagarara neza muri electrolytite yo mu mazi, ubwinshi bw’ingufu, hamwe n’uburinganire buke.ubushobozi., amashanyarazi asubira inyuma, amashanyarazi meza, ubwinshi nuburyo bworoshye bwo gukora4,5.Kugeza ubu, nubwo bateri yambere yindege ya zinc ikoreshwa mubikorwa byubucuruzi nkibikoresho bifasha kumva, ibyuma bya gari ya moshi n'amatara yo kugendagenda, bateri zo mu kirere cya zinc zifite ubushobozi bwo gukomera kwinshi ugereranije na bateri ishingiye kuri lithium.Ibi birakwiriye ko dukomeza ubushakashatsi kuri bateri yindege ya zinc kugirango ikoreshwe mu bikoresho bya elegitoroniki bigendanwa, ibinyabiziga by’amashanyarazi, ububiko bw’ingufu nini ndetse no gushyigikira ingufu zishobora kongera ingufu 6,7.
Imwe mu ntego zingenzi ni ukunoza imikorere ya ogisijeni ikora kuri electrode yo mu kirere, aribyo kugabanya umwuka wa ogisijeni (ORR) hamwe n’ubwihindurize bwa ogisijeni (OER), hagamijwe guteza imbere ubucuruzi bwa batiri ya Zn-air.Kugirango bigerweho, amashanyarazi meza arashobora gukoreshwa kugirango yongere igipimo cyimyitwarire bityo yongere imikorere.Kugeza ubu, umwuka wa ogisijeni hamwe na catalizator ikora neza wasobanuwe neza mubitabo8,9,10.Nubwo cataliste ikora ishobora koroshya imiterere ya electrode no kugabanya igihombo cyimurwa ryinshi, gishobora gufasha kugabanya ibiciro byumusaruro, mubikorwa, catalizator ikwiranye na ORR akenshi ntabwo ibereye OER, naho ubundi11.Iri tandukaniro mubushobozi bwo gukora ritera catalizator guhura nurwego runini rushoboka, rushobora guhindura imiterere yubuso bwigihe.Mubyongeyeho, kwuzuzanya kwingufu zingana hagati bisobanura ko imbuga zikora kuri catalizator zishobora kuba zitandukanye kuri buri reaction, zishobora kugorana neza.
Ikindi kibazo gikomeye kuri bateri ya kabiri ya Zn-air ni igishushanyo cya ogisijenielectrode, cyane cyane kuberako cataliste ikora ya ORR na OER ikorera mubitangazamakuru bitandukanye.Ikwirakwizwa rya gaze ya ORR igomba kuba hydrophobique kugirango gaze ya ogisijeni yinjire muri catalitiki, mugihe kuri OER ubuso bwa electrode bugomba kuba hydrophilique kugirango byoroherezwe kuvanaho umwuka wa ogisijeni.Ku mutini.1 yerekana ibishushanyo bitatu bya kabiri bya ogisijeni ya elegitoronike yakuwe mubisubirwamo na Jorissen12, aribyo (i) catalizator ya monolayeri ikora, (ii) catalizator ebyiri cyangwa nyinshi, na (iii) ibice bitatu bya electrode.
Kubushakashatsi bwa mbere bwa electrode, ikubiyemo catalizike imwe gusa igizwe na catalizator icyarimwe itera icyarimwe ORR na OER, niba membrane ishyizwe muriki gishushanyo, noneho inteko ya membrane-electrode (MEA) ikorwa nkuko bigaragara.Ubwoko bwa kabiri burimo ibitanda bibiri (cyangwa byinshi) bya catalizator hamwe nubushake butandukanye hamwe na hydrophobicity kugirango ubare itandukaniro muri zone reaction 13,14,15.Rimwe na rimwe, ibitanda byombi bya catalitiki biratandukana, hamwe na hydrophilique ya OER ireba electrolyte hamwe na hydrophobique igice cya ORR ireba impera zifunguye za electrode 16, 17, 18. selile igizwe na reaction ebyiri- electrode yihariye ya electrode na electrode ya zinc19,20.Imbonerahamwe S1 yerekana ibyiza nibibi bya buri gishushanyo.
Ishyirwa mu bikorwa rya electrode itandukanya ORR na OER reaction yabanje kwerekana iterambere ryumukino wo gusiganwa19.Ibi ni ukuri cyane cyane kubintu bitatu bya electrode, aho kwangirika kwa catalizator idahindagurika hamwe ninyongeramusaruro bigabanywa kandi kurenza urugero birashobora kugenzurwa murwego rwose rushoboka.Kubera izo mpamvu, twakoresheje ibice bitatu bya electrode Zn-ikirere muriyi mirimo.
Muri iyi ngingo, twabanje guhitamo imikorere ya ORR itanga imbaraga mugereranya ibyuma bitandukanye byinzibacyuho, ibikoresho bya karubone, hamwe na catalizator hamwe nubushakashatsi bwa disiki ya electrode (RDE).Inzibacyuho ya oxyde ikunda kuba electrocatalysis nziza bitewe nuburyo butandukanye bwa okiside;reaction zirashobora gutangizwa byoroshye imbere yibi bikoresho21.Kurugero, okiside ya manganese, oxyde ya cobalt, hamwe na oxyde ivanze ya cobalt (nka NiCo2O4 na MnCo2O4) 22,23,24 yerekana ORR nziza mubihe bya alkaline bitewe na d-orbitale yuzuye yuzuye, ingufu za electron zemerera electron akazi no kunoza gukata neza.Byongeye kandi, ni byinshi cyane mubidukikije kandi bifite amashanyarazi yemewe, amashanyarazi menshi kandi ahamye.Mu buryo nk'ubwo, ibikoresho bya karubone bikoreshwa cyane, bifite ibyiza byo gutwara amashanyarazi menshi hamwe nubuso bunini.Rimwe na rimwe, heteroatom nka azote, boron, fosifore, na sulferi byinjijwe muri karubone kugira ngo bihindure imiterere, birusheho kunoza imiterere ya ORR y'ibikoresho.
Dushingiye ku bisubizo byubushakashatsi, twashyizemo catalizator ya OVR yatoranijwe muri electrode ya gaz ikwirakwizwa (GDE) hanyuma tuyipima mubucucike butandukanye.Cataliste ikora neza cyane ya ORR GDE noneho yakusanyirijwe mumashanyarazi yacu atatu-electrode ya kabiri ya Zn-air ya batiri hamwe na reaction yihariye ya OER electrode yatunganijwe mubikorwa byacu byashize26,27.Ubushobozi bwa electrode ya ogisijeni yakurikiranwe mugihe cyo gusohora no kwishyuza amagare kugirango bige ku ngaruka zimikorere nkubucucike buriho, ubukana bwa electrolyte, ubushyuhe bwimikorere ya selile, nubuziranenge bwa ogisijeni.Hanyuma, batteri ya Zn-air ya kabiri yasuzumwe mugihe cyamagare ikomeza mugihe gikwiye.
MnOx28 yateguwe nuburyo bwa redox chimique: ml 50 ya 0.04 M KMnO4 yumuti (Fisher Scientific, 99%) yongewe kuri ml 100 ya 0.03 M Mn (CH3COO) 2 (Fisher Scientific, 98%) kugirango habeho imvura yijimye.Uruvange rwahinduwe kuri pH 12 hamwe na hydroxide ya sodium ya sodium, hanyuma ushiramo inshuro 3-5 kuri 2500 rpm kugirango ukusanyirize imvura.Imvura noneho yogejwe namazi ya deionion kugeza ibara ryumutuku wa ion ya permanganate yazimye.Amaherezo, kubitsa byumye byumuyaga kuri 333 K ijoro ryose hanyuma bigahinduka.
Spinel oxyde Co3O4, NiCo2O4, na MnCo2O4 yashizwemo no kubora.NiCo2O4 na MnCo2O4 byateguwe hongerwaho 0.5 M (14.5 g) nikel (II) nitrate hexahydrate, Ni (NO3) 2⋅6H2O (Fisher Scientific, 99,9%) cyangwa 0.5 M (12,6 g) tetrahydrate manganese (II) nitrate Mn (NO3) ).) 2 4H2O (Sigma Aldrich, ≥ 97%) na 1 M (29.1 g) cobalt (II) nitrate hexahydrate, Co (NO3) 2 6H2O (Fisher Scientific, 98 +%, ACS reagents) muri methanol (Fisher Scientific, 99.9% ) muri 100 ml yamashanyarazi.Methanol yongewemo uduce duto kuri nitrate yinzibacyuho hamwe no gukomeza gukurura kugeza habonetse igisubizo kimwe.Igisubizo cyahise cyimurirwa ku kintu gikomeye kandi gishyuha ku isahani ishyushye, hasigara umutuku wijimye.Ikomeye yabazwe kuri 648 K kuri 20 h mu kirere.Ibikomokaho byaje guhinduka ifu nziza.Oya Ni (NO3) 2 6H2O cyangwa Mn (NO3) 2 4H2O yongeyeho mugihe cyo guhuza Co3O4.
Graphene nanosheets ifite ubuso bwa 300 m2 / g (Sigma Aldrich), graphene yometse kuri azote (Sigma Aldrich), ifu yumukara wa karubone (Vulcan XC-72R, Cabot Corp., 100%), MnO2 (Sigma Aldrich) na 5 wt.% Pt / C (Acros Organics) yakoreshejwe nkuko biri.
Ibipimo bya RDE (Pine Research Instrumentation) byakoreshejwe mugusuzuma ibikorwa bya catalizaires zitandukanye za ORR muri 1 M NaOH.Irangi rya catalitiki igizwe na 1 mg catalizator + 1 ml deionised (DI) H2O + 0.5 ml isopropanol (IPA) + 5 µl 5 wt% Nafion 117 (Sigma-Aldrich) yakoreshejwe nkuko biri.Iyo Vulcan XC-72R yongeyeho, irangi rya catalitiki ryari rigizwe na 0.5 mg catalizator + 0.5 mg Vulcan XC-72R + 1 ml DI HO + 0.5 ml IPA + 5 µl 5 wt% Nafion 117 kugirango harebwe ibintu byuzuye.Uruvange rwakozwe muminota 20 hanyuma rushyirwa hamwe ukoresheje Cole-Parmer LabGen 7 Series homogenizer kuri 28.000 rpm kuminota 4.Irangi ryashyizwe muri alikoti eshatu za 8 μl hejuru ya electrode yikirahure ya karubone (Pine Instrument Company) ifite umurambararo wa mm 4 (ahantu hakorera ≈ 0.126 cm2) hanyuma ikama hagati yurwego kugirango itange umutwaro wa cm 120 mgg -2.Hagati ya porogaramu, ikirahuri cya karubone electrode yubuso yagiye isukurwa neza hamwe na MicroCloth (Buehler) na mm 1.0 na pome ya alumina 0.5 mm (MicroPolish, Buehler) ikurikirwa na sonic muri H2O.
ORR gazi ikwirakwiza electrode ntangarugero yateguwe dukurikije protocole twasobanuye mbere28.Ubwa mbere, ifu ya catalizator na Vulcan XC-72R yavanze mubipimo byuburemere 1: 1.Noneho imvange yumuti wa polytetrafluoroethylene (PTFE) (60 wt.% Muri H2O) hamwe numuti ufite igipimo cya IPA / H2O ya 1: 1 wongeyeho ifu yumye ivanze.Sonicate irangi rya catalitike muminota igera kuri 20 hanyuma homogenize muminota igera kuri 4 kuri 28.000 rpm.Irangi ryashyizwe muburyo bworoshye na spatula kurupapuro rwa karubone mbere yo gukata mm 13 z'umurambararo (AvCarb GDS 1120) hanyuma iruma kugeza igihe catisale ya mg 2 cm2 igeze.
OER electrode yahimbwe na cathodic electrodeposition ya Ni - Fe hydroxide catalizaires kuri mm 15 x 15 mm ibyuma bitagira umwandamesh(DeXmet Corp, 4SS 5-050) nkuko byatangajwe 26.27.Electrodeposition yakorewe muri selile-electrode isanzwe igice cya selile (selile yometse kuri polymer ingana na cm 20) hamwe na Pt gride nka compte electrode na Hg / HgO muri 1 M NaOH nka electrode yerekana.Emerera catalizator yometseho ibyuma bitagira umuyonga kugirango yumuke mbere yo gutema ubuso bungana na cm2 cm2 hamwe na mm 10 z'ubugari bwa karuboni.
Kugereranya, ubucuruzi bwa ORR na OER electrode yakoreshejwe nkuko yakiriwe kandi igeragezwa mubihe bimwe.Ubucuruzi bwa ORR electrode (QSI Nano Gas Diffusion Electrode, Quantum Sphere, 0,35 mm z'ubugari) igizwe na manganese na carbone oxyde ikozwe hamwe na nikel mesh ikusanya amashanyarazi, mugihe electrode yubucuruzi ya OER (ubwoko bwa 1.7, anode idasanzwe ya Magneto, BV) ifite uburebure bwa 1.3 mm.kugeza kuri mm 1,6 yaguye titanium mesh yashizwemo na Ru-Ir ivanze nicyuma.
Imiterere ya morfologiya hamwe nibigize catalizator yaranzwe no gukoresha FEI Quanta 650 FEG yogusuzuma electron microscope (SEM) ikorera munsi yumuvuduko mwinshi hamwe na voltage yihuta ya 5 kV.Ifu ya X-ray itandukanya (XRD) yakusanyirijwe kuri Bruker D8 Advance X-ray diffractometer ifite isoko y'umuringa (λ = 1.5418 Å) hanyuma isesengurwa hakoreshejwe software ya Bruker Diffraction Suite EVA.
Ibipimo byose byamashanyarazi byakozwe hakoreshejwe Biologic SP-150 potentiostat na software ya EC-lab.Ingero za RDE na GDE zapimwe kumurongo usanzwe wa electrode eshatu zigizwe na 200 cm3 yikirahure yikirahure hamwe na capillary ya Laggin nka electrode yerekana.Pt mesh na Hg / HgO muri 1 M NaOH byakoreshejwe nka compteur na electrode yerekana.
Kubipimo bya RDE muri buri bushakashatsi, hakoreshejwe electrolyte nshya 1 M NaOH, ubushyuhe bwayo bwagumishijwe kuri 298 K ukoresheje ubwogero bwamazi buzenguruka (TC120, Impano).Umwuka wa ogisijeni (BOC) wasimbukaga muri electrolyte unyuze mu kirahure gifite ikirahure cya 25-50 µm byibura 30 min mbere ya buri bushakashatsi.Kugirango ubone umurongo wa ORR polarisiyasi, ubushobozi bwarasuzumwe kuva 0.1 kugeza kuri 0.5 V (ugereranije na Hg / HgO) ku gipimo cya scan ya 5 mV s -1 kuri 400 rpm.Voltammogramme yumukino yabonetse mugukuraho ubushobozi buri hagati ya 0 na -1.0 V na Hg / HgO ku kigero cya 50 mV s-1.
Kubipimo bya HDE, electrolyte ya 1 M NaOH yagumishijwe kuri 333 K hamwe nogeswa amazi.Ubuso bukora bwa 0.8 cm2 bwerekanwe na electrolyte hamwe nogukomeza gutanga ogisijeni kuruhande rwinyuma rwa electrode ku kigero cya cm3 / min.Intera ihamye hagati ya electrode ikora na electrode yerekana yari mm 10, naho intera iri hagati ya electrode ikora na compte electrode yari mm 13-15.Nickel wire na mesh bitanga amashanyarazi kuruhande rwa gaze.Ibipimo bya Chronopotentiometric byafashwe kuri 10, 20, 50 na 100 mA cm-2 kugirango hamenyekane imbaraga za electrode.
Ibiranga electrode ya ORR na OER byasuzumwe muri selile 200 cm3 yikirahure yikirahure hamwe na PTFE29.Igishushanyo mbonera cya sisitemu cyerekanwe mu gishushanyo S1.Electrode muri bateri ihujwe muri sisitemu ya electrode eshatu.Electrode ikora yari igizwe na reaction yihariye ya ORR na OER electrode ihujwe na module ya relay (Indirimbo, SRD-05VDC-SL-C) hamwe na microcontroller (Raspberry Pi 2014 © moderi B + V1.2) hamwe na anode ya zinc.nka couple electrode hamwe na electrode yerekana Hg / HgO muri 4 M NaOH byari intera ya mm 3 uvuye kuri zinc anode.Inyandiko ya Python yanditse kugirango ikore kandi igenzure Raspberry Pi na Module ya Relay.
Akagari kahinduwe kugirango kibashe kwakira anode ya zinc (Goodfellow, mm 1 z'ubugari, 99,95%) kandi igipfundikizo cya polymer cyemerera electrode gushyirwa mumwanya uhamye wa m 10.Mm 4 zitandukanye.Amashanyarazi ya Nitrile yashizemo electrode mu gipfundikizo, kandi insinga za nikel (Alfa Aesar, 0,5 mm z'umurambararo, zometse kuri 99.5% Ni) zakoreshwaga mu guhuza amashanyarazi ya electrode.Zinc foil anode yabanje guhanagurwa na isopropanol hanyuma ikoresheje amazi ya deioniyo, hanyuma hejuru ya fayili yari itwikiriwe na kaseti ya polypropilene (Avon, AVN9811060K, 25 µm z'ubugari) kugirango yerekane ahantu hakora nka cm 0.8.
Ubushakashatsi bwose bwo gusiganwa ku magare bwakorewe muri 4 M NaOH + 0.3 M ZnO electrolyte kuri 333 K keretse bivuzwe ukundi.Kuri iyi shusho, Ewe kubijyanye na Hg / HgO bivuga ubushobozi bwa electrode ya ogisijeni (ORR na OER), Ece kubijyanye na Hg / HgO byerekana ubushobozi bwa electrode ya zinc, Ecell kubijyanye na Hg / HgO byerekana byuzuye selile selile cyangwa itandukaniro rishobora.hagati ya bateri ebyiri zishoboka.Umwuka wa ogisijeni cyangwa umwuka washyizwe ku ruhande rwinyuma rwa electrode ya OPP ku gipimo gihoraho cya 200 cm3 / min.Ihagarikwa ryamagare nigikorwa cya electrode yizwe mubucucike bwa 20 mA cm-2, igihe cyizunguruka cya 30 min, nigihe cyo kuruhuka kwa OCV kuminota 1 hagati ya buri gice cyizunguruka.Nibura byibuze inzinguzingo 10 zakozwe kuri buri kizamini, kandi amakuru yakuwe muri cycle 1, 5, na 10 kugirango hamenyekane imiterere ya electrode mugihe.
Imiterere ya catalizator ya ORR yaranzwe na SEM (Igishusho 2), kandi ibipimo by'ifu ya X-ray itandukanya byemeje imiterere ya kristu y'icyitegererezo (Ishusho 3).Ibipimo byuburyo bwa catalizator byatanzwe mu mbonerahamwe ya 1. 1. Iyo ugereranije okiside ya manganese, ubucuruzi MnO2 mubitini.2a igizwe nuduce duto, kandi uburyo bwo gutandukanya ishusho ya 3a bihuye na JCPDS 24-0735 kuri tetragonal β-MnO2.Ibinyuranye na byo, hejuru ya MnOx ku gishushanyo cya 2b herekana ibice byiza kandi byiza, bihuye nuburyo bwo gutandukana ku gishushanyo cya 66 ° bihuye nimpinga (110), (220), (310), (211), na (541) ya tetrahedrally yibanze α-MnO2 hydrate, JCPDS 44-014028.
(a) MnO2, (b) MnOx, (c) Co. .% Pt / C.
Imiterere ya X-ya ya % platine / karubone.
Ku mutini.2c - e, morfologiya yubuso bwa oxyde ishingiye kuri cobalt Co3O4, NiCo2O4, na MnCo2O4 igizwe nudutsiko duto duto duto.Ku mutini.3c - e yerekana ko izo nzibacyuho zoseicyumaoxyde ifite imiterere ya spinel hamwe na sisitemu isa na cubic sisitemu (JCPDS 01-1152, JCPDS 20-0781, na JCPDS 23-1237).Ibi byerekana ko uburyo bwo kubora bwumuriro bushobora kubyara okiside yicyuma cyane, nkuko bigaragazwa nimpinga zikomeye zisobanuwe neza muburyo bwo gutandukana.
SEM amashusho yibikoresho bya karubone yerekana impinduka nini.Ku mutini.2f Vulcan XC-72R karubone yumukara igizwe na nanoparticles yuzuye.Ibinyuranye, isura ya graphene ku gishushanyo cya 2g ni amasahani adahwitse cyane hamwe na agglomerations.Nyamara, N-dope graphene (Igishusho 2h) bigaragara ko igizwe nibice bito.Imiterere ya X-ray itandukanya ya Vulcan XC-72R, graphene yubucuruzi ya nanosheets, na N-dope graphene mumashusho.3f yerekana impinduka nto muri 2θ indangagaciro za (002) na (100) impinga ya karubone.Vulcan XC-72R izwi nka grafite ya mpandeshatu muri JCPDS 41-1487 ifite impinga (002) na (100) igaragara kuri 24.5 ° na 43.2 °.Mu buryo nk'ubwo, impinga ya (002) na (100) ya N-dope graphene igaragara kuri 26.7 ° na 43.3 °.Imbaraga zinyuma zagaragaye muburyo bwa X-ray itandukanya ya Vulcan XC-72R na graphene ya azote-iterwa na kamere iterwa cyane nuburyo bwibikoresho muri morfologiya yabo.Ibinyuranyo, uburyo bwo gutandukanya graphene nanosheets yerekana impinga ikarishye, ikomeye (002) kuri 26.5 ° na mpinga ntoya (100) kuri 44 °, byerekana imiterere ya kirisitiya y'uru rugero.
Hanyuma, mugitabo.2i SEM ishusho ya 5 wt.% Pt / C yerekana ibice bya karubone bimeze nkinkoni hamwe nubusa.Cubic Pt igenwa kuva kuri mpinga nyinshi muburyo bwa 5 wt% Pt / C itandukanya ishusho ya 3g, naho impinga ya 23 ° ihuye nimpinga ya (002) ya karubone ihari.
Gukuraho umurongo ORR catalizator voltammogram yanditswe ku gipimo cya 5 mV s-1.Kubera imbogamizi zo kwimura imbaga, amakarita yakusanyijwe (Igishusho 4a) mubisanzwe afite S-shusho igera mubibaya bifite amahirwe menshi.Kugabanya ubucucike buriho, jL, ubushobozi bwa E1 / 2 (aho j / jL = ½) hamwe nubushobozi bwo gutangira kuri -0.1 mA cm-2 byakuwe muri ibyo bibanza kandi byashyizwe ku mbonerahamwe ya 2. Birakwiye ko tumenya ko mumitini.4a, catalizator irashobora gushyirwa mubice ukurikije ubushobozi bwa E1 / 2 muri: (I) okiside yicyuma, (II) ibikoresho bya karubone, na (III) ibyuma byiza.
Gukuramo umurongo wa voltammogrammes ya (a) catalizator na (b) firime yoroheje ya catalizator na XC-72R, yapimwe kuri RDE ikirahure cya karuboni ya karuboni 400 rpm hamwe na scan ya 5 mV s-1 muri O2 kwiyuzuza kuri 298 K muri 1 M NaOH cf.
Icyuma cya oxyde ya Mn na Co mumatsinda ya I nderekana ubushobozi bwambere bwa -0.17 V na -0.19 V, naho E1 / 2 indangagaciro ziri hagati ya -0.24 na -0.26 V. Kugabanya kugabanuka kwi oxyde yicyuma byerekanwe muburinganire .(1) na (2), bigaragara hafi yubushobozi bwo gutangira mubishushanyo.4a ihuza ubushobozi busanzwe bwintambwe yambere 2e yinzira itaziguye ya ORR muburinganire.(3).
Icyuma kivanze cya oxyde MnCo2O4 na NiCo2O4 mumatsinda amwe yerekana gukosora gato ubushobozi bwambere kuri -0.10 na -0.12 V, ariko bugumana agaciro ka E1 / 2 kangana na 10. - 0.23 volt.
Itsinda rya II ibikoresho bya karubone byerekana agaciro keza E1 / 2 kurenza itsinda rya mbere ryicyuma.Ibikoresho bya Graphene bifite ubushobozi bwambere -0.07 V na E1 / 2 agaciro ka -0.11 V, mugihe ubushobozi bwambere na E1 / 2 bya 72R Vulcan XC- ni -0.12V na -0.17V.Mu itsinda rya III, 5 wt% Pt / C yerekanye ubushobozi bwiza bwambere kuri 0.02 V, E1 / 2 ya -0.055 V, kandi ntarengwa kuri -0.4 V, kubera ko kugabanuka kwa ogisijeni kwabayeho binyuze mubucucike bwinzira ya 4e .Ifite kandi E1 / 2 yo hasi cyane kubera umuvuduko mwinshi wa Pt / C hamwe na kinetic ihinduka ya reaction ya ORR.
Igishushanyo S2a cyerekana isesengura rya Tafel kumurongo wa catalizator zitandukanye.Agace kagenzurwa na kinetike ya 5 wt. kuri Tafel Pt / C ni –63.5 mV ss - 1, isanzwe kuri Pt ku bucucike buke dE / d log i = –2.3 RT / F31.32 aho intambwe igena igipimo ikubiyemo ihinduka rya ogisijeni iva muri physisorption ikajya chemisorption33,34.Agaciro ka Tafel kumurongo wibikoresho bya karubone biri mukarere kamwe na Pt / C (-60 kugeza kuri 70 mV div-1), byerekana ko ibyo bikoresho bifite inzira zisa na ORR.Okiside yicyuma ya Co na Mn raporo ya Tafel ihanamye kuva kuri -110 kugeza kuri -120 mV dec-1, ikaba ari dE / d log i = -2.3 2RT / F, aho intambwe igena igipimo ari electron ya mbere.kwimura intambwe ya 35, 36. Agaciro gato cyane kamanutse kanditse kuri okiside ivanze ya oxyde NiCo2O4 na MnCo2O4, hafi -170 mV dec-1, byerekana ko hariho ion ya OH- na H2O hejuru ya oxyde, birinda ogisijeni kwinjiza no ihererekanyabubasha rya elegitoronike, bityo bikagira ingaruka kuri ogisijeni.inzira yo kugabanya 35.
Ikigereranyo cya Kutetsky-Levich (KL) cyakoreshejwe kugirango hamenyekane ibipimo ngenderwaho bya kinetic ya sisitemu ya catalizator itandukanye itimuwe.mu kuringaniza..
Kuva ku kuringaniza.(5) Kugabanya ubucucike bwa jL buringaniye na kare kare yumuzi wo kuzunguruka.Kubwibyo, KL ingana..
aho ν ni ubukonje bwa kinematike ya electrolyte 1 M NaOH (1.1 × 10-22 cm2 s - 1) 37, D ni coefficient de diffuzione ya O2 muri 1 M NaOH (1.89 × 10-5 cm2 s - 1) 38, ω ni rpm ni umuvuduko wo kuzunguruka, C nubushakashatsi bwa ogisijeni mubisubizo byinshi (8.4 × 10-7 mol cm - 3) 38.
Kusanya umurongo wuzuye wa voltammogramu ukoresheje RDE kuri 100, 400, 900, 1600, na 2500 rpm.Indangagaciro zavanywe kuri -0.4 V mukarere gato ko kwimura imbaga kugirango bategure igishushanyo cya KL, ni ukuvuga -j-1 na ω-1 // 2 kuri catalizator (Ishusho S3a).Koresha ibigereranyo.Muburinganire (6) na (7), ibipimo byerekana imikorere ya catalizator, nkubucucike bwa kinetic ititaye ku ngaruka zo kwimura abantu benshi jk, bigenwa nu ngingo yo guhuza na y axis, n'umubare wa ihererekanyabubasha rya elegitoronike rigenwa na gradient K yumurongo.Bashyizwe ku mbonerahamwe ya 2.
5 wt% Pt / C na XC-72R bifite agaciro gake cyane jk indangagaciro, byerekana kinetika yihuse kubikoresho.Nyamara, umusozi wa XC-72R wikubye hafi kabiri ko kuri 5 wt% Pt / C, bikaba biteganijwe kuva K yerekana umubare wa electron zihererekanwa mugihe cyo kugabanya ogisijeni.Mubyukuri, umugambi wa KL kuri 5 wt% Pt / C ugomba kunyura mu nkomoko 39 mugihe gito cyo kwimura abantu benshi, icyakora ibi ntibigaragara mubishusho S3a, byerekana imipaka ya kinetic cyangwa ikwirakwizwa ryibisubizo.Ibi birashobora kuba kubera ko Garsani n'abandi.40 berekanye ko ibidahuye bito muri topologiya na morphologie ya firime ya catalitiki ya Pt / C bishobora kugira ingaruka kumikorere yibikorwa bya ORR.Ariko, kubera ko firime zose za catalizator zateguwe muburyo bumwe, ingaruka zose kubisubizo zigomba kuba zimwe kuburugero rwose.Graphene KL yambukiranya point -0.13 mA-1 cm2 iragereranywa nki XC-72R, ariko -0.20 mA-1 cm2 yambukiranya igishushanyo cya N-dope graphene KL yerekana ko ubucucike buriho buterwa ahanini voltage kuri catalitike ihindura.Ibi birashobora guterwa nuko azote doping ya graphene igabanya amashanyarazi muri rusange, bikavamo buhoro buhoro uburyo bwo kohereza electronique.Ibinyuranye, agaciro K rwose ka azote-dope graphene ni ntoya kuruta iya graphene kuko kuba azote ifasha gukora ibibuga bikora kuri ORR41,42.
Kuri oxyde ishingiye kuri manganese, aho ihuriro ryagaciro kanini ryaragaragaye - 0.57 mA-1 cm2.Nubwo bimeze bityo, agaciro K rwose ka MnOx kari munsi cyane ya MnO2 kandi kegereye 5 wt%.% Pt / C.Inomero zo kohereza electron ziyemeje kuba hafi.MnOx ni 4 naho MnO2 iri hafi ya 2. Ibi bihuye nibisubizo byatangajwe mubitabo, bivuga ko umubare wohereza electron mu nzira α-MnO2 ORR ari 4, naho β-MnO243 mubusanzwe uri munsi ya 4. Gutyo rero Inzira za ORR ziratandukanye kuburyo butandukanye bwa polymorphique ya catalizator ishingiye kuri oxyde ya manganese, nubwo igipimo cyintambwe yimiti ikomeza kuba imwe.By'umwihariko, catalizike ya MnOx na MnCo2O4 ifite numero yo kohereza electron hejuru ya gato gato ya 4 kuko kugabanuka kwa okiside ya manganese iboneka muri izi catalizator bibaho icyarimwe hamwe no kugabanya ogisijeni.Mubikorwa byabanjirije iki, twasanze kugabanuka kwamashanyarazi ya oxyde ya manganese bibaho muburyo bumwe nko kugabanya ogisijeni mumuti wuzuye azote28.Umusanzu wibisubizo kuruhande biganisha kumubare wabazwe wa electron zirenze gato 4.
Isangano rya Co3O4 ni ≈ .4 0.48 mA-1 cm2, ikaba itari mibi ugereranije nuburyo bubiri bwa okiside ya manganese, kandi nimero igaragara ya electron igenwa nagaciro ka K ingana na 2. Gusimbuza Ni muri NiCo2O4 na Mn muri MnCo2O4 na Co biganisha ku kugabanuka kwindangagaciro zuzuye K, byerekana iterambere ryimikorere ya electron ya kinetics ivanze nicyuma kivanze.
Carbone substrate yongewe kuri wino ya catalizike ya ORR kugirango yongere amashanyarazi kandi yorohereze imipaka ibyiciro bitatu bikwiye muri electrode ikwirakwiza gaze.Vulcan-XC-72R yatoranijwe kubera igiciro cyayo gito, ubuso bunini bwa 250 m2 · g-1, hamwe no guhangana na 0.08 kugeza 1 Ω · cm44.45.Umugambi wa LSV wa catalizator ntangarugero ivanze na Vulcan XC-72R saa 400 rpm irerekanwa mumashusho 1. 4b.Ingaruka zigaragara cyane zo kongeramo Vulcan XC-72R ni ukongera ubwinshi bwubu.Menya ko ibi bigaragara cyane kuri okiside yicyuma, hiyongereyeho 0,60 mA cm-2 kuri oxyde imwe yicyuma, 0,40 mA cm-2 kuri okiside ivanze, na 0.28 mA cm-2 kuri graphene na graphene.N. Ongeraho 0,05 mA cm-2.−2.Kwiyongera kwa Vulcan XC-72R kuri wino ya catalizator nabyo byatumye habaho impinduka nziza mubushobozi bwo gutangira hamwe na E1 / 2 igice cya kabiri cyumuraba kuri catalizator zose usibye graphene.Izi mpinduka zirashobora kuba igisubizo gishoboka cyo kongera amashanyarazi yubutaka bwakoreshejwe 46 no kunoza imikoranire47 hagati ya catalizator kuri catalizike ya Vulcan XC-72R.
Ibibanza bya Tafel bihuye nibipimo bya kinetic kuriyi mvange ya catalizator byerekanwe mubishusho S2b na Imbonerahamwe 3.Indangagaciro za Tafel zari zimwe kubikoresho bya MnOx na graphene hamwe na XC-72R kandi nta na XC-72R, byerekana ko inzira zabo za ORR zitagize ingaruka.Nyamara, okiside ishingiye kuri cobalt Co3O4, NiCo2O4 na MnCo2O4 yatanze agaciro keza ka Tafel gahanamye hagati ya -68 na -80 mV dec-1 ifatanije na XC-72R byerekana ihinduka ryinzira ya ORR.Igishushanyo S3b cyerekana umugambi wa KL icyitegererezo cya catalizator hamwe na Vulcan XC-72R.Muri rusange, igabanuka ryagaciro ntangarugero rya jk ryagaragaye kuri catalizator zose zivanze na XC-72R.MnOx yerekanye igabanuka ryinshi mubiciro byuzuye bya jk kuri 55 mA-1 cm2, mugihe NiCo2O4 yanditseho igabanuka rya 32 mA-1 cm-2, naho graphene yerekanaga igabanuka rito kuri 5 mA-1 cm2.Twakwanzura ko ingaruka za Vulcan XC-72R kumikorere ya catalizator zigarukira kubikorwa byambere bya catalizator mubijyanye na OVR.
Vulcan XC-72R ntabwo ihindura agaciro K indangagaciro za NiCo2O4, MnCo2O4, graphene, na graphene ya azote.Nyamara, K agaciro ka Co3O4 yagabanutse cyane hiyongereyeho Vulcan XC-72R, byerekana ubwiyongere bwa electroni zoherejwe na ORR.Bene ubwo bufatanye bwa Co3O4 hamwe nibice bya karubone byavuzwe muri ref.48, 49. Mugihe hatabonetse inkunga ya karubone, Co3O4 yatekereje guteza imbere igabanywa rya HO2- kuri O2 na OH-50.51, ibyo bikaba bihuza neza na Co3O4′s yohereza electroni ya nimero igera kuri 2 mumeza 2. Rero, umubiri wa adsorption ya Co3O4 kumurongo wa karubone biteganijwe ko uzabyara inzira ya 2 + 2 e-electron ya ORR inzira52 yambere amashanyarazi ya O2 kugeza HO2- kuri interineti ya catalizike ya Co3O4 na Vulcan XC-72R (ikigereranyo cya 1) hanyuma HO2 - Ikigereranyo cyihuse cyane Ubuso bwicyuma cyahinduwe kuri O2 hagakurikiraho amashanyarazi.
Ibinyuranye, agaciro ntarengwa ka K MnOx kiyongereye hiyongereyeho Vulcan XC-72R, ibyo bikaba bigaragaza igabanuka ryumubare wa elegitoronike uva kuri 4.6 ukagera kuri 3.3 (Imbonerahamwe 3).Ibi biterwa no kuba hari imbuga ebyiri kumurongo wa karubone ikomatanya ibyiciro bibiri bya electron.Kugabanuka kwambere kwa O2 kuri HO2- bibaho byoroshye kumashanyarazi ya karubone, bikavamo kwiyongera gake kubice bibiri bya electron ya ORR53.
Ihame rya catalizator ryasuzumwe muri GDE igice-selile murwego rwubucucike buriho.Ku mutini.5 yerekana ibibanza bishoboka nigihe cya GDE MnOx, MnCo2O4, NiCo2O4, graphene, na graphene ya azote.MnOx yerekana imikorere myiza muri rusange hamwe na ORR imikorere yubucucike buri hejuru kandi buringaniye, byerekana ko ikwiye kurushaho kunozwa.
Chronopotentiometrie yicyitegererezo cya HDE kuri ubu kuva kuri 10 kugeza 100 mA / cm2 muri 1 M NaOH, 333 K, O2 umuvuduko wa 200 cm3 / min.
MnCo2O4 nayo isa nkigumana umutekano mwiza wa ORR murwego rwubucucike buriho, ariko hejuru yubucucike buri hejuru ya 50 na 100 mA cm-2 nini ya overvoltage nini yerekana ko MnCo2O4 idakora neza nka MnOx.Graphene GDE yerekana imikorere ya ORR yo hasi cyane kurwego rwubu rwageragejwe, yerekana igabanuka ryihuse ryimikorere kuri 100 mA cm-2.Kubwibyo, mubihe byubushakashatsi bwatoranijwe, MnOx GDE yatoranijwe kugirango ikore ibizamini muri sisitemu ya kabiri ya Zn-air.