Zenzeka nini iintshukumo zeElectrochemical?

Utshintsho lwe-electrochemical lwenzeka xa amandla ekhemikhali eguqukela kumandla ombane okanye ngokuphendululekileyo ngokudluliselwa kwe-electron kujongano phakathi kwe-electrode kunye ne-electrolyte. Ezi ntshukumo zenzeka kuyo nayiphi na inkqubo apho umsinga wombane uqhuba utshintsho lweekhemikhali okanye apho ukusabela kweekhemikhali kuvelisa umbane.

Electrochemical Reactions

Iimpendulo ze-Electrochemical zifuna izinto ezintathu ezisisiseko ezisebenza kunye. I-electron conductor isebenza njenge-electrode apho ukusabela kwenzeka kumphezulu. I-ionic conductor{2}}ngokuqhelekileyo isisombululo se-electrolyte esiqulethe ii-ion ezinyibilikisiweyo{3}}ivumela intlawulo ukuba ihambe phakathi kwee-electrode. Isekethe epheleleyo idibanisa la macandelo, ivumela ukuhamba kwe-electron ngendlela yangaphandle.

Ukusabela kwenzeka ngokukodwa kwi-electrode{{0}ujongano lwe-electrolyte, ngaphakathi kwee-angstroms ezimbalwa ukusuka kumphezulu womqhubi. Le ndawo imxinwa yokusabela ikhona ngenxa yokuba ii-electron zihlala zihamba kuphela kwii-electronic conductors ezifana neentsimbi, ngelixa ii-ion zithwala i-electrolyte.

Iiseli zeGalvanic zibonisa ukusabela kwe-electrochemical okwenzeka ngokuzenzekelayo ukuvelisa umbane. Kwezi nkqubo, i-oxidation yenzeka kwi-anode ngelixa ukuncipha kwenzeka kwi-cathode. Umahluko onokubakho wekhemikhali phakathi kwezi siqingatha zibini-zompendulo ziqhuba ii-electron kwisekethe yangaphandle.

Ukukhutshwa kwebhetri kubonisa le nkqubo izenzekelayo. Xa usebenzisa iibhetri ze-forklift, ukuphendula kweekhemikhali phakathi kwezinto ze-electrode kunye nee-electron zokukhululwa kwe-electrolyte ezenza amandla emoto. ilothe -iasidi ezahlukeneyo zisebenzisa ilothe dayoksayidi kunye nepleyiti zesiponji ezintywiliselwe kwi-asidi yesulfuric, kunye ne-electrochemical reaction eguqula amandla ekhemikhali agciniweyo kumandla ombane afunekayo ekuphakamiseni imisebenzi.

Iseli kaDaniel iwubonisa ngokucacileyo lo mgaqo. I-Zinc metal oxidizes kwenye i-electrode, ikhupha ii-electron ezihamba ngocingo ukunciphisa ii-ion zobhedu kwenye i-electrode. Le ntambo ye-electron iquka umsinga wombane, iqhubeka de i-reactants iphelelwe okanye inkqubo ifikelele kwi-equilibrium.

Iiseli ze-Electrolytic zimele imeko echaseneyo-yempendulo ye-electrochemical engenzekiyo nje kodwa ifuna amandla ombane asetyenzisiweyo ukuze aqhubeke. Amandla ombane angaphandle anyanzelela ukuba -kutshintshe ngokuzenzekela kweekhemikhali.

Ukutshaja ibhetri egcwalisekayo kubonisa lo mgaqo. Xa uqhagamshela ibhetri{1} yeasidi kwitshaja, amandla ombane asetyenzisiweyo abuyisela umva ukusabela kokuphuma. I-lead sulfate iguqula umva kwi-lead dioxide kunye ne-sponge lead, ngelixa i-sulfuric acid concentration inyuka kwi-electrolyte. Igalelo lamandla ombane lakha kwakhona amandla ekhemikhali aya kuthi kamva anike amandla isixhobo sakho.

I-electrolysis yamanzi inika omnye umzekelo ocacileyo. Ukusebenzisa amandla ombane awaneleyo kwii-electrode ezintywiliselwe emanzini kwahlula iimolekyuli ze-H₂O kwi-hydrogen kunye neegesi zeoksijini. Umbane ofunekayo mawugqithise umahluko onokubakho kwikhemikhali phakathi kwe-oxidation kunye nesiqingatha sokunciphisa{2}}ireactions.

I-Industrial electroplating ixhomekeke kule ndlela yokusabela ngenkani. Umsinga wombane uqhuba iiyoni zetsimbi ukusuka kwisisombululo ukuya kwinto eqhubayo, udala ukhuselo okanye ukuhombisa ukutyabeka ngenkqubo ye-electrochemical ebinakwenzeka ngaphandle kokusetyenziswa kwamandla.

Iimpendulo ze-Electrochemical zibonisa ubuntununtunu obubalulekileyo bobushushu. Uninzi lweebhetri zisebenza ngokugqibeleleyo phakathi kwe-0 kunye ne-45℃, kunye nokusebenza okuthotywayo ngaphandle kolu luhlu. Ukushisa okubandayo kwandisa ukuchasana kwangaphakathi, ukunciphisa ukunyakaza kwe-ion ngokusebenzisa i-electrolyte kunye nokunciphisa ukuphuma kwamandla. I-lead {{5}ibhetri yeasidi ilahlekelwa yi-50% umthamo kwi- - 20℃, ngelixa iibhetri ze-lithium-ion zigcina ukusebenza okungcono kunye ne-20% kuphela yokulahlekelwa kwamandla kwiqondo lokushisa elifanayo.

Ubushushu bukhawulezisa ukuwohloka kweekhemikhali kodwa kunokukhawulezisa iikinetics zokusabela ngaphakathi kwemida ekhuselekileyo. Nangona kunjalo, ubushushu obugqithisileyo obungaphezulu kwe-60℃bubeka umngcipheko wokubaleka kwe-thermal kwiibhetri ze-lithium, apho iintshukumo eziphuma ngaphandle zikwazi ukuzigcina{2}} kwaye zibe yingozi. Iqondo lobushushu-indalo exhomekeke kwindalo ithetha ukuba ukusabela kwe-electrochemical kwenzeka ngokulula kumaqondo obushushu aphakathi apho ukushukuma kwe-ion kuhlala kuphezulu ngaphandle kokubangela ukubola.

Ukugxininiswa kwe-Electrolyte kuchaphazela amazinga okuphendula kakhulu. Kwiibhetri ze-asidi -, ubunzima obuthile be-asidi ye-sulfuric butshintsha ngexesha lokukhupha, lehla ukusuka malunga ne-1.27 xa ihlawulwe ngokupheleleyo ukuya ngaphantsi kwe-1.10 xa iphelile. Oku kuncipha koxinzelelo kuthoba i-electrochemical reaction de i-asidi engonelanga ishiyeke kugqithiso lwe-electron olusebenzayo.

Electrochemical Reactions

Iimpendulo ze-Electrochemical zenzeka xa inkqubo inombane owaneleyo wokuqhuba ukuhanjiswa kwe-electron. I-Nernst equation inika ubungakanani obu budlelwane, ibonisa ukuba amandla eseli axhomekeke njani kugxininiso lwe-react, ubushushu, kunye nomgangatho onokwenzeka we-electrode wemathiriyeli ebandakanyekayo.

Amandla omgangatho we-electrode amisela ukuba zeziphi iintshukumo eziqhubekayo ngokuzenzekelayo. Izixhobo ezikumgangatho ombi ngakumbi zinika ii-electron ngokulula, zizenza ii-anode ezifanelekileyo. Abo banamaxabiso amahle kakhulu bamkela ii-electron, ezisebenza njenge-cathodes. Umahluko phakathi kwezi zinto zinokwenzeka useka amandla ombane weseli{3}}amandla okuqhuba entshukumo.

Xa iseli ye-voltaic iphuma, amandla eseli ayancipha ngokuthe ngcembe njengoko ugxininiso lwe-reactant lutshintsha. Ukusabela kuyaqhubeka de inkqubo ifikelele kwi-equilibrium, ngelo xesha amandla anokubakho awela kwi-zero kwaye akukho ukuhamba kwe-electron. Ngaphambi kwesi simo sokulingana, i-electrochemical reaction iqhubela phambili kwireyithi ehambelana noxinano lwangoku.

Iintshukumo zokwenyani zombane we-electrochemical zihlala zifuna amandla ombane angaphezulu{0}ongeziweyo ngaphaya kobuncinci be-thermodynamic. La mandla ongezelelweyo woyisa imiqobo yokuvula ukudluliselwa kwe-electron kunye nokulinganiselwa kothutho oluninzi. I-overpotential iyahluka ngohlobo lokuphendula, izinto ze-electrode, kunye nokuxinana kwangoku.

Ukusabela ngokukhawuleza okunamandla aphantsi aqhubeleka ngokufanelekileyo kumbane ogqithileyo omncinci. Ukusabela okucothayo kufuna amandla angaphaya okuphumeza ukuhamba okusebenzayo ngoku. Oku kucacisa ukuba kutheni ezinye iinkqubo ze-electrolytic zifuna amandla ombane aphezulu kakhulu kunokubalo lwethiyori lucebisa.

Iimpendulo ze-Electrochemical zinika amandla izixhobo ezininzi kunye neenkqubo. Iibhetri eziziiprayimari ezikwiitotshi kunye nolawulo olukude zixhomekeke kwiimpendulo ezingajikiyo ezivelisa umbane de ziphele izinto ezisabelayo. Iibhetri zesibini ezimotweni kunye ne-electronics zisebenzisa iimpendulo ezibuyiselwa umva, zivumela intlawulo ephindaphindiweyo{2}}ukukhupha imijikelo.

I-fuel cell imele isicelo esikhethekileyo apho i-electrochemical reactions iguqula i-fuel ngqo kumbane kunye nokusebenza okuphezulu. I-Hydrogen i-oxidizes kwi-anode ngelixa i-oksijini iyancipha kwi-cathode, ivelisa amanzi kuphela njengemveliso. Ngokungafaniyo neebhetri, iiseli zepetroli zifuna unikezelo lwamafutha rhoqo ukugcina ukusabela.

I-Corrosion ibonisa ukuphendula okungafunekiyo kwe-electrochemical okwenzeka ngokuzenzekelayo xa isinyithi sidibana nokufuma kunye ne-oxygen. Irust ye-iron ibumba ngokusabela kwe-oxidation kwiindawo ze-anodic, kunye nokuhamba kwe-electron kwiindawo ze-cathodic apho i-oxygen iyancipha. Ukuqonda ezi zixhobo ze-electrochemical kunceda iinjineli ukuba ziphuhlise izambatho ezikhuselayo kunye nokubola{2}}i-alloys ezixhathisayo.

I-electrochemistry yoshishino yenza ukuba{0}}iinkqubo zemveliso ezinkulu. Ukuveliswa kwe-aluminiyam kuxhomekeke kwi-electrolysis ye-aluminium oxide etyhidiweyo, isebenzisa imisinga emikhulu yokunciphisa ii-ion ze-aluminiyam. Inkqubo ye-chloralkali i-electrolyzes i-brine ukuvelisa igesi yeklorin kunye ne-sodium hydroxide, zombini iikhemikhali ezibalulekileyo zemizi-mveliso.

Electrochemical Reactions

Amazinga e-electrochemical reaction axhomekeke kwizinto ezininzi ezidibeneyo. Uxinaniso lwangoku{1}}indawo yangoku yeyunithi ye-electrode{2}}ingqamana ngokuthe ngqo nereyithi yokusabela ngokwemithetho kaFaraday. Uxinaniso oluphezulu lwangoku luthetha ukuba ii-electron ezininzi zidlulisa ngesekhondi, ukukhawulezisa ukuguqulwa kweekhemikhali.

Ukuthuthwa kwabantu abaninzi kunciphisa iintshukumo ezininzi ze-electrochemical. Ii-reactants kufuneka zifikelele kumphezulu we-electrode, kwaye iimveliso kufuneka zihambe ukuze zigcine i-concentration gradients. Ukusasazwa, ukufuduka, kunye nokuhanjiswa kulawula ezi nkqubo zothutho. Ukuvuselela i-electrolyte okanye ukuyila ukuhamba{3}}ngokusebenzisa iiseli kuphucula ukuthuthwa kwabantu abaninzi kwaye konyusa izinga lokuphendula elifikelelekayo.

Umphezulu we-electrode ubaluleke kakhulu. Imiphezulu emikhulu ibonelela ngeesayithi ezininzi zokudluliselwa kwe-electron, okwenza ukuba imisinga eyongezelelweyo iphelele kuxinaniso lwangoku olufanayo. Oku kuchaza ukuba kutheni i-electrode yebhetri isebenzisa izakhiwo ezivuzayo ezinommandla ophezulu womphezulu-ukuya{3}}umlinganiselo wevolumu, ukukhulisa ujongano apho ukusabela kwenzeka khona.

Izinto ze-electrode ngokwayo zichaphazela i-kinetics yokuphendula ngokusebenzisa i-catalytic effects. Ezinye iimathiriyeli zithoba amandla okuvula kusabela okuthile, okubavumela ukuba baqhubele phambili ngokukhawuleza kumandla aphantsi. IPlatinam yenza i-hydrogen oxidation kunye nokunciphisa ioksijini ngokufanelekileyo, iyenza ixabiseke kwii-electrode zeeseli zamafutha nangona ixabiso layo.

I-electrode-i-interface ye-electrolyte inesakhiwo esintsonkothileyo esibizwa ngokuba ngumbane ophindwe kabini. Lo mmandla ugxininisa intlawulo kwii-nanometers ezimbalwa, ukudala iindawo zombane ezinzulu ezifikelela kwi-10⁷ V / cm. Umaleko ophindwe kabini usebenza njenge-capacitor, intlawulo yokugcina echaphazela i-electrochemical reaction kinetics.

Iiyoni ezikwisisombululo ziziqhelanise kufutshane nomphezulu we-electrode ohlawuliweyo. I-Cations idibanisa kufuphi ne-electrode engalunganga, ngelixa i-anion igxila kwii-electrode ezilungileyo. Olu lungiselelo lwe-ion lukhusela intlawulo ye-electrode kwaye luchaphazela ukuba zeziphi iintlobo ezinokufikelela kumphezulu ukuze zisabele. Ulwakhiwo oluphindwe kabini lutshintsha ngokuguquguqukayo njengoko amandla e-electrode ayahluka, aphembelela iindlela zokusabela kunye namazinga.

Ukuqonda iziphumo zomaleko ophindwe kabini kungqina kubalulekile ekuphuculeni iinkqubo ze-electrochemical. Abaphandi bafunda ezi nanoscale phenomena ukuyila i-electrode yebhetri engcono, ukuphucula ukuxhathisa ukubola, kunye nokuphuhlisa i-electrocatalysts esebenzayo ngakumbi. Umaleko ophindwe kabini umele apho imolekyuli{2}}inqanaba lekhemistri idibana neziganeko zombane ezinkulu.

Iiseli zeGalvanic zenza umbane ngokusuka kwimichiza ezenzekelayo, njengokukhupha iibhetri. Iiseli ze-Electrolytic zisebenzisa amandla ombane asetyenzisiweyo ukuqhuba iintshukumo ezingezizo ezizenzekelayo, njengokutshaja iibhetri okanye i-electroplating. Ukwahlula okuphambili kukuba ngaba ukusabela kwenzeka ngokwemvelo (galvanic) okanye kufuna amandla angaphandle (electrolytic).

Ewe, nangona kunqabile. Iibhetri zelizwe -eziqinileyo zisebenzisa i-electrolyte eqinileyo eqhuba ii-ion ngolwakhiwo lwazo lwekristale. -ubushushu obuphezulu beeseli zamafutha eoksayidi zisebenzisa i-electrolyte zeceramic. Kwanezinye iigesi zinokusebenza njenge-electrolytes phantsi kweemeko ezithile. Nangona kunjalo, i-electrolyte yolwelo ihlala ixhaphake kakhulu ngenxa ye-ionic conductivity ephezulu.

Kwi-equilibrium, ireyithi yokusabela eya phambili kunye ne-reverse ibhalansi ngqo. Akukho tshintsho lweekhemikhali olunetha lwenzekayo, ngoko ke akukho zi-electron zihamba kwisekethe. Iseli enokubakho yehla iye kwiqanda kuba inkqubo ifikelele kweyona ndawo isezantsi yamandla. Ukongeza ii-reactants okanye ukusebenzisa i-voltage yangaphandle kunokuqalisa kwakhona ukusabela.

Amaqondo obushushu aphezulu ngokuqhelekileyo anyusa amazinga okusabela ngokukhawulezisa intshukumo ye-ion kunye nokunciphisa imiqobo yokuvula amandla. Nangona kunjalo, ukushisa okugqithisileyo kunokonakalisa amacandelo ebhetri okanye kubangele ukusabela okubalekayo. Amaqondo obushushu abandayo acotha ukusabela ngokumangalisayo, anciphisa amandla aphumayo. Inkqubo nganye ye-electrochemical inoluhlu olufanelekileyo lobushushu bokusebenza okuphezulu.

Iimpendulo ze-Electrochemical bridge chemistry kunye nobunjineli bombane ngeendlela ezichukumisa ubomi bethu bemihla ngemihla rhoqo. Ukusuka kwibhetri ekwi-smartphone yakho ukuya -kukutya kokutya kwizakhiwo zentsimbi, ezi nkqubo zokudlulisa i-electron kumphezulu we-electrode zenza ukuba ubuchwephesha bale mihla bubekho. Ukusabela kwenzeka nanini na xa indibaniselwano eyiyo yee-electrode, i-electrolyte, kunye nokuba amandla okuqhuba ekhemikhali okanye amandla ombane asetyenziswayo adibana-ukuguqula amandla phakathi kweekhemikhali kunye neefomu zombane ngobuchule obumangalisayo.

Electrochemical Reactions