Kwenzeka Nini Ukusabela Kwe-Electrochemical?

Ukusabela kwe-electrochemical kwenzeka lapho amandla amakhemikhali eguqulela kumandla kagesi noma okuphambene nalokho ngokudluliswa kwama-electron endaweni yokuhlangana phakathi kwe-electrode ne-electrolyte. Lokhu kusabela kwenzeka kunoma iyiphi isistimu lapho amandla kagesi eqhuba ushintsho lwamakhemikhali noma lapho ukuhlangana kwamakhemikhali kukhiqiza ugesi.

Electrochemical Reactions

Ukusabela kwe-electrochemical kudinga izakhi ezintathu eziyisisekelo ezisebenza ndawonye. I-electron conductor isebenza njenge-electrode lapho ukusabela kwenzeka khona phezulu. I-conductor ye-ionic{2}}ngokuvamile isisombululo se-electrolyte esiqukethe ama-ion ancibilikisiwe{3}}ivumela ukushaja ukuthi kugeleze phakathi kwama-electrode. Isifunda esiphelele sixhuma lezi zingxenye, okwenza ukunyakaza kwama-electron ngendlela yangaphandle.

Ukusabela kwenzeka ngokuqondile kusixhumi esibonakalayo se-electrode{{0}electrolyte, phakathi kwama-angstrom ambalwa ukusuka endaweni yekhondatha. Le ndawo yokusabela ewumngcingo ikhona ngoba ama-electron ahlala ehamba kuphela kumakhondatha e-elekthronikhi njengezinsimbi, kuyilapho ama-ion ephatha amandla nge-electrolyte.

Amaseli e-Galvanic abonisa ukusabela kwe-electrochemical okwenzeka ngokuzenzakalelayo ukukhiqiza ugesi. Kulezi zinhlelo, i-oxidation kwenzeka ku-anode kuyilapho ukuncipha kwenzeka ku-cathode. Umehluko ongaba khona amakhemikhali phakathi kwalezi zindlela ezimbili-ezisabelayo ushayela ama-electron kumjikelezo wangaphandle.

Ukukhishwa kwebhethri kuyisibonelo sale nqubo ezenzakalelayo. Uma usebenzisa amabhethri e-forklift, ukusabela kwamakhemikhali phakathi kwezinto ze-electrode kanye nama-electron okukhululwa kwe-electrolyte anika amandla injini. Izinhlobo ze-asidi-zomthofu zisebenzisa i-lead dioxide ne-sponge lead plate ezicwiliswe ku-sulfuric acid, kanye ne-electrochemical reaction eguqula amandla amakhemikhali agciniwe abe amandla kagesi adingekayo ukuze kuphakanyiswe imisebenzi.

Iseli likaDaniell libonisa isimiso ngokucacile. I-Zinc metal i-oxidize kwenye i-electrode, idedele ama-electron ageleza ngocingo ukuze anciphise ama-ion ethusi kwenye i-electrode. Lokhu kugeleza kwe-electron kuhlanganisa amandla kagesi, okuqhubekayo kuze kube yilapho ama-reactants ephela noma uhlelo lufinyelela ekulinganeni.

Amaseli e-Electrolytic amele isimo esiphambene-ne-electrochemical reactions engenzeki ngokuzenzakalelayo kodwa edinga amandla kagesi asetshenzisiwe ukuze kuqhutshekwe. Amandla kagesi angaphandle aphoqa-ukuguqulwa kwamakhemikhali okuzenzakalelayo.

Ukushaja ibhethri elishajekayo kukhombisa lo mgomo. Uma uxhuma ibhethri{1}}le-asidi eshajani, i-voltage esetshenzisiwe ibuyisela emuva ukusabela kokuphuma. I-lead sulfate iguqula ibuyele ekubeni i-lead dioxide nesipontshi ihola, kuyilapho ukugxila kwe-sulfuric acid kukhuphuka ku-electrolyte. Okokufaka kwamandla kagesi kwakha kabusha amandla amakhemikhali azonika amandla imishini yakho kamuva.

I-electrolysis yamanzi inikeza esinye isibonelo esicacile. Ukusebenzisa i-voltage eyanele kuwo wonke ama-electrode acwiliswe emanzini kuhlukanisa ama-molecule e-H₂O abe yi-hydrogen namagesi omoya-mpilo. I-voltage edingekayo kufanele yeqe umehluko ongaba khona amakhemikhali phakathi kwe-oxidation kanye nokuncishiswa kwengxenye-kusabela.

I-Industrial electroplating incike kulo mshini wokusabela ophoqelelwe. I-electric current ishayela ama-ion ensimbi isuka kwisixazululo iye entweni eqhutshwayo, idale okokuvikela noma okokuhlobisa ngenqubo ye-electrochemical ebingeke yenzeke ngaphandle kwamandla asetshenzisiwe.

Ukusabela kwe-electrochemical kubonisa ukuzwela okukhulu kwezinga lokushisa. Amabhethri amaningi asebenza kahle kakhulu phakathi kuka-0℃no-45℃, nokusebenza okonakele ngaphandle kwalolu banga. Amazinga okushisa abandayo akhulisa ukumelana kwangaphakathi, anciphisa ukunyakaza kwe-ion ngokusebenzisa i-electrolyte futhi anciphise ukuphuma kwamandla. Ibhethri eliholayo{{5}le-asidi lilahlekelwa amandla angu-50% -ku-20℃, kuyilapho amabhethri e-lithium-ion agcina ukusebenza okungcono ngokulahleka komthamo okungu-20% kuphela ngezinga lokushisa elifanayo.

Ukushisa kusheshisa ukuwohloka kwamakhemikhali kodwa futhi kungasheshisa ama-kinetics wokusabela ngaphakathi kwemikhawulo ephephile. Kodwa-ke, ukushisa okweqile okungaphezu kuka-60℃kuyingozi ekuphelelweni kokushisa kumabhethri e-lithium, lapho ukusabela kwe-exothermic kuba ukuzinza{2}}futhi kube yingozi. Izinga lokushisa-imvelo encikile isho ukusabela kwe-electrochemical kwenzeka kalula emazingeni okushisa aphakathi nendawo lapho ukuhamba kwe-ion kuhlala kuphezulu ngaphandle kokubangela ukubola.

Ukugxila kwe-Electrolyte kuthinta kakhulu amazinga okuphendula. Kumabhethri{{1}e-asidi omthofu, amandla adonsela phansi athile e-sulfuric acid ashintsha phakathi nokukhipha, ehla esuka cishe ku-1.27 uma eshajwe ngokugcwele ukuya ngaphansi kuka-1.10 uma eqediwe. Lokhu kuncipha kokugxila kunciphisa ukusabela kwe-electrochemical kuze kube yilapho i-asidi enganele isala ekudlulisweni kwe-electron ephumelelayo.

Electrochemical Reactions

Ukusabela kwe-electrochemical kwenzeka lapho uhlelo lunamandla anele kagesi okushayela ukudluliswa kwama-electron. Isibalo se-Nernst silinganisa lobu budlelwano, ikhombisa ukuthi amandla eseli ancike kanjani ekugxilweni kwe-react, izinga lokushisa, namandla ajwayelekile ama-electrode wezinto ezihilelekile.

Amandla ama-electrode ajwayelekile anquma ukuthi yikuphi ukusabela okuqhubeka ngokuzenzakalelayo. Izinto ezinekhono elibi kakhulu elijwayelekile zinikela ngama-electron kalula, okuwenza abe anode afanele. Labo abanamanani amahle kakhulu bamukela ama-electron, asebenza njengama-cathodes. Umehluko phakathi kwalawa mandla usungula amandla kagesi eseli{3}}amandla okushayela okusabela.

Lapho iseli le-voltaic liphuma, amandla eseli ayancipha kancane kancane njengoba ukugxila kwe-reactant kushintsha. Ukusabela kuyaqhubeka kuze kube yilapho isistimu ifinyelela ekulinganeni, ngaleso sikhathi amandla ehla aze afike kuqanda futhi kungabikho ukugeleza kwe-electron enetha okwenzekayo. Ngaphambi kwalesi simo sokulingana, ukusabela kwe-electrochemical kuqhubeka ngenani elilinganayo nokuminyana kwamanje.

Ukusabela kwangempela kwe-electrochemical ngokuvamile kudinga amandla angaphezu kwamandla kagesi-kagesi angeziwe ngaphezu kobuncane be-thermodynamic. La mandla engeziwe anqoba izithiyo zokuvula ukudluliswa kwama-electron kanye nemikhawulo yokuthutha ngobuningi. I-overpotential iyahlukahluka ngohlobo lokusabela, impahla ye-electrode, kanye nokuminyana kwamanje.

Ukusabela okusheshayo okunamandla angaphezu kwamandla aphansi kuqhubeka kahle ku-voltage encane eyeqile. Ukusabela okuvilaphayo kudinga amandla amakhulu ukuze kuzuzwe ukugeleza kwamanje okusebenzayo. Lokhu kuchaza ukuthi kungani ezinye izinqubo ze-electrolytic zidinga ama-voltage aphezulu kakhulu kunezibalo ezisikiselwayo.

Ukusabela kwe-electrochemical amandla amadivaysi nezinqubo ezingenakubalwa. Amabhethri ayinhloko kumathoshi nezilawuli kude ancike ekuphenduleni okungahlehliseki okukhiqiza ugesi kuze kuphele izinto ezisabelayo. Amabhethri esibili ezimotweni nakuma-electronics asebenzisa ukusabela okubuyiseleka emuva, okuvumela ukushaja okuphindaphindiwe{2}}imijikelezo yokukhipha.

I-fuel cell imele uhlelo lokusebenza oluyingqayizivele lapho ukusabela kwe-electrochemical kuguqula uphethiloli uwenze ugesi ngokusebenza kahle okuphezulu. I-Hydrogen i-oxidize ku-anode kuyilapho umoya-mpilo wehla ku-cathode, ikhiqiza amanzi kuphela njenge-byproduct. Ngokungafani namabhethri, ama-fuel cell adinga ukunikezwa kukaphethiloli okuqhubekayo ukuze agcine ukusabela.

Ukugqwala kuyisibonelo sokusabela kwe-electrochemical okungafuneki okwenzeka ngokuzenzakalelayo lapho insimbi ithinta umswakama nomoya-mpilo. Ukugqwala kwe-iron kwakha ngokusabela kwe-oxidation kumasayithi e-anodic, nokugeleza kwe-electron ezindaweni ze-cathodic lapho umoya-mpilo wehla khona. Ukuqonda lezi zindlela ze-electrochemical kusiza onjiniyela bakhe ama-coatings avikelayo kanye nokugqwala{2}}ama-alloys angangeni.

I-electrochemistry yezimboni inika amandla-izinqubo zokukhiqiza ezinkulu. Ukukhiqizwa kwe-aluminium kuncike ku-electrolysis ye-aluminium oxide encibilikisiwe, kusetshenziswa imisinga emikhulu ukunciphisa ama-ion e-aluminium. Inqubo ye-chloralkali i-electrolyzes brine ukuze ikhiqize igesi ye-chlorine ne-sodium hydroxide, kokubili amakhemikhali ezimboni abalulekile.

Electrochemical Reactions

Izilinganiso zokusabela kwe-Electrochemical zincike ezintweni eziningana ezixhumene. Ukuminyana kwamanje-indawo yamanje yeyunithi ngayinye ye-electrode{2}}ihlobana ngokuqondile nezinga lokusabela ngokuvumelana nemithetho kaFaraday. Ukuminyana okuphezulu kwamanje kusho ama-electron amaningi adluliselayo ngomzuzwana, okusheshisa ukuguqulwa kwamakhemikhali.

Ukuthuthwa kwabantu abaningi kunciphisa ukusabela okuningi kwe-electrochemical. Ama-reactants kufanele afinyelele indawo ye-electrode, futhi imikhiqizo kufanele isuke ukuze igcine ama-concentration gradients. Ukusabalalisa, ukufuduka, kanye nokuhamba kubusa lezi zinqubo zokuthutha. Ukushukumisa i-electrolyte noma ukugeleza kokuklama{3}}ngamaseli kuthuthukisa ukuthuthwa kwabantu abaningi futhi kwenyusa amazinga okusabela afinyelelekayo.

Indawo ye-Electrode ibaluleke kakhulu. Izindawo ezinkudlwana zinikeza amasayithi amaningi okudlulisa ama-electron, okuvumela ama-currents amaningi aphezulu ngokuminyana kwamanje okufanayo. Lokhu kuchaza ukuthi kungani ama-electrode ebhethri esebenzisa izakhiwo ezimbotshana ezinendawo ephezulu-ukuze{3}}ukuze{3}}izilinganiso zevolumu, akhulise isixhumi esibonakalayo lapho ukusabela kwenzeka khona.

I-electrode material ngokwayo ithonya i-reaction kinetics ngokusebenzisa imiphumela ye-catalytic. Ezinye izinto ezisetshenziswayo zehlisa amandla okwenza kusebenze ukusabela okuthile, okuzivumela ukuthi ziqhubeke ngokushesha ngangokunokwenzeka okuphansi. Iplatinamu igqugquzela i-hydrogen oxidation nokunciphisa umoya-mpilo ngempumelelo, iyenze ibe yigugu kuma-electrode amangqamuzana kaphethiloli naphezu kwezindleko zayo.

Isixhumi esibonakalayo se-electrode-se-electrolyte sinesakhiwo esiyinkimbinkimbi esibizwa ngokuthi i-electrode double layer. Lesi sifunda sigxilisa ukushaja ngama-nanometer ambalwa, sidala izinkambu zikagesi eziqinile ezifinyelela ku-10⁷ V/cm. Isendlalelo esikabili sisebenza njenge-capacitor, ishaja yokugcina ethonya kinetics yokusabela kwe-electrochemical.

Ama-ion kusixazululo aziqondisa eduze kwendawo ye-electrode eshajiwe. Ama-cations ahlangana eduze kwama-electrode angemahle, kuyilapho ama-anion egxila kuma-electrode aqondile. Lolu hlelo lwe-ion luhlola ukushajwa kwama-electrode futhi luthinta ukuthi yiziphi izinhlobo ezingafinyelela phezulu ukuze zisabele. Isakhiwo sesendlalelo esikabili sishintsha ngokushintshashintshayo njengoba amandla e-electrode ehluka, athonya izindlela zokusabela kanye namazinga.

Ukuqonda imiphumela yongqimba oluphindwe kabili kufakazela ukuthi kubalulekile ekwenzeni kahle izinhlelo ze-electrochemical. Abacwaningi bacwaninga lezi zenzakalo ze-nanoscale ukuze bakhe ama-electrode ebhethri angcono, bathuthukise ukumelana nokugqwala, futhi bakhe ama-electrocatalyst asebenza kahle kakhulu. Isendlalelo esikabili simelela lapho ikhemistri yeleveli-ihlangana khona nezimo zikagesi ezinkulu.

Amaseli e-Galvanic akhiqiza ugesi ngokuhlangana kwamakhemikhali okuzenzakalelayo, njengokuphuma kwamabhethri. Amaseli e-Electrolytic asebenzisa amandla kagesi asetshenzisiwe ukushayela{1}}ukusabela okuzenzakalelayo, njengamabhethri okushaja noma i-electroplating. Umehluko oyinhloko ukuthi ukusabela kwenzeka ngokwemvelo (galvanic) noma kudinga amandla angaphandle (i-electrolytic).

Yebo, nakuba kungavamile. Amabhethri esimo esiqinile-asebenzisa ama-electrolyte aqinile aphatha ama-ion ngesakhiwo sekristalu.-Izinga lokushisa eliphezulu{3}}amaseli e-solid oxide fuel asebenzisa ama-electrolyte e-ceramic. Ngisho namanye amagesi angasebenza njengama-electrolyte ngaphansi kwezimo ezithile. Kodwa-ke, ama-electrolyte awuketshezi ahlala evame kakhulu ngenxa ye-ionic conductivity ephakeme.

Ekulinganisweni, izilinganiso zokusabela eziya phambili nangemuva zibhalansisa ngqo. Alukho ushintsho lwamakhemikhali olunetha okwenzekayo, ngakho awekho ama-electron ageleza kusekethe. Amandla eseli ehla aze afike kuqanda ngoba isistimu ifinyelele kusimo sayo samandla aphansi kakhulu. Ukwengeza ama-reactants noma ukusebenzisa i-voltage yangaphandle kungaqalisa kabusha ukusabela.

Amazinga okushisa aphakeme ngokuvamile akhuphula amazinga okusabela ngokusheshisa ukunyakaza kwe-ion kanye nokwehlisa imigoqo yokuvula amandla okuvula. Nokho, ukushisa okudlulele kungalimaza izingxenye zebhethri noma kuqalise ukusabela okubalekayo. Amazinga okushisa abandayo anciphisa ukusabela ngendlela emangalisayo, ehlisa ukuphuma kwamandla. Isistimu ngayinye ye-electrochemical inebanga lokushisa elilungile lokusebenza okuphezulu.

Ukusabela kwe-Electrochemical kuhlanganisa ikhemistri kanye nobunjiniyela bukagesi ngezindlela ezithinta impilo yethu yansuku zonke njalo. Kusuka ebhethrini eliku-smartphone yakho ukuya -ekubambiseni ukugqwala ezakhiweni zensimbi, lezi zinqubo zokudlulisa ama-electron endaweni yama-electrode zenza ubuchwepheshe besimanje bungenzeka. Ukusabela kwenzeka noma nini lapho inhlanganisela efanele yama-electrode, i-electrolyte, namandla okushayela amakhemikhali noma i-voltage esetshenziswayo ihlangana{3}}iguqula amandla phakathi kwamafomu amakhemikhali nawogesi ngendlela esebenza kahle kakhulu.

Electrochemical Reactions