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Electrocatalytic materials for borhydride oxidation

dc.contributor.advisorŠljukić-Paunković, Biljana
dc.contributor.otherMentus, Slavko
dc.contributor.otherPašti, Igor
dc.contributor.otherVujković, Milica
dc.creatorMilikić, Jadranka
dc.date.accessioned2017-03-18T19:49:36Z
dc.date.available2017-03-18T19:49:36Z
dc.date.available2020-07-03T09:34:42Z
dc.date.issued2016-11-30
dc.identifier.urihttp://nardus.mpn.gov.rs/handle/123456789/7724
dc.identifier.urihttp://eteze.bg.ac.rs/application/showtheses?thesesId=4678
dc.identifier.urihttps://fedorabg.bg.ac.rs/fedora/get/o:14869/bdef:Content/download
dc.identifier.urihttp://vbs.rs/scripts/cobiss?command=DISPLAY&base=70036&RID=48758543
dc.description.abstractDanas se kao primarni izvori energije u industriji koriste fosilna goriva, nafta i prirodan gas. Zalihe navedenih goriva su ograničene, a i posledice korišćenja ovih goriva su veoma nepovoljne po životnu sredinu pa se traga za obnovljivim i ekološki prihvatljivijim izvorima energije. Usled svetske energetske krize, koja još uvek traje, značajno je oživelo naučno i tehnološko interesovanje za NaBH4 za skladištenje ili kao izvor energije. Prva istraživanja su se odnosila na skladištenje vodonika dok je nešto kasnije pomenuta direktna elektrooksidacija NaBH4 za primenu u direktnim borhidridnim gorivnim ćelijama. Gorivne ćelije su elektrohemijske ćelije, koje hemijsku energiju goriva pretvaraju u električnu energiju. Danas primenu prvenstveno imaju u automobilskoj industriji, jer ne postoje zagađujući izduvni gasovi, što ima blagotvoran uticaj na životnu sredinu. Na osnovu brojnih istraživanja zlato i srebro pokazuju najbolju elektrohemijsku efikasnost u elektrooksidaciji borhidrida, gde je postignut visok prinos elektrona, za razliku od npr. platine gde je prinos manji. Međutim, treba istaći da je zlato veoma skupo i ima sporu kinetiku elektrooksidacije borhidrida pa se zato traga za novim elektrokatalizatorima. Cilj ovog rada je analiza anodnih materijala za oksidaciju natrijum borhidrida i njihova primena u direktnim borhidridnim gorivnim ćelijama. U okviru ovog rada testirano je pet materijala sa različitim masenim sadržajima gradivnih komponenti. Testirane su komercijalne legure platine i nikla ili kobalta na ugljeničnoj osnovi, zatim, legure platina retke zemlje (od kojih je testiran disprozijum), takođe, nikal i elementi retke zemlje (disprozijum i samarijum), potom, elektrokatalizatori paladijuma sintetisani na dve različite ugljenične osnove i elektrokatalizatori srebra sintetisanih na ugljeniku. Od pomenutih elektrokatalizatora pokazano je da je najefikasniji za oksidaciju borhidrida platina-nikal ili kobalt. Efikasnost je utvrđena na osnovu brojnih elektrohemijskih i kinetičkih parametara. Zapravo, pomenuti elektrokatalizatori platine pre svega daju najveće gustine struje, najnižu energiju aktivacije i najveći broj razmenjenih elektrona.Veoma je bitno i napomenuti i cenu ovih elektrokatalizatora koja je svakako niža od čiste platine na ugljeniku. Slično ponašanje su pokazali i testrani elektrokatalizatori paladijuma, koji takođe ima nižu cenu od platine. Nešto manju efikasnost za oksidaciju borhidrida pokazale su redom nikal-retke zemlje, platina-retke zemlje, dok su najmanje aktivni elektrokatalizatori na bazi srebra...sr
dc.description.abstractNowadays, fossil fuels, oil and natural gas are used as primary sources of energy in industry. The supplies of the abovementioned fuels are limited, and the consequences of their use are very harmful to the environment and so there is a search for renewable and ecologically acceptable sources of energy. Scientific and technological interest in NaBH4, as a storage of energy or hydrogen, has significantly revived because of the world energy crisis which is still ongoing. The first researches have dealt with hydrogen storage while the direct electrooxidation NaBH4 for use in fuel cells has been mentioned later. Fuel cells are electrochemical cells which convert chemical energy of a fuel into electrical energy. Today, they are primarily applied in automotive industry because there are no polluting exhaust gases which has a beneficial impact on the environment. On the basis of numerous researches, gold and silver show the best electrochemical efficiency in borohydride electrooxidation where a high yield of electrons is achieved unlike platinum for example, where the yield is lower. However, it should be pointed out that gold is very expensive and has a slow borohydride electrooxidation kinetics and that is why there is a search for new electrocatalysts. The aim of this work is analysis of anode materials for sodium borohydride oxidation reaction and their application in direct borohydride fuel cells. In the scope of this work, five materials with different mass contents of constituent components were tested. Commercial alloys of platinum and nickel or cobalt supported on carbon, then, alloys of platinum and rare earths (of which dysprosium was tested), and also, nickel and rare earths (dysprosium and samarium), then, carbon-supported palladium and silver electrocatalysts. It was shown that carbon-supported platinum-nickel and platinum-cobalt arethe most efficient for borohydride oxidation among the mentioned electrocatalysts. The efficiency is determined basedon the values ofseveral electrochemical and kinetic parameters. In fact, the abovementioned platinum electrocatalysts give the highest current densities, the lowest activation energy and the largest number of exchanged electrons. It is very important to mention the price of these electrocatalysts which is surely lower than pure carbon-supported platinum. The tested electrocatalysts of palladium, which also have lower price than platinum, have shown the similar behaviour. A slightly lower efficiency of borohydride oxidation was shown bynickelrare earth and then platinum-rare earth, while the lowest activity was shown by the carbon-supported silver electrocatalysts...en
dc.formatapplication/pdf
dc.languagesr
dc.publisherУниверзитет у Београду, Факултет за физичку хемијуsr
dc.relationinfo:eu-repo/grantAgreement/MESTD/Integrated and Interdisciplinary Research (IIR or III)/45014/RS//
dc.relationinfo:eu-repo/grantAgreement/MESTD/Integrated and Interdisciplinary Research (IIR or III)/45004/RS//
dc.rightsopenAccessen
dc.sourceУниверзитет у Београдуsr
dc.subjectdirektna borhidridna gorivna ćelijasr
dc.subjectdirect borohydride fuel cellen
dc.subjectsodium borohydride oxidation reactionen
dc.subjectalloys of platinum and transition metalsen
dc.subjectalloys of platinum and dysrposiumen
dc.subjectalloys of nickel and rare earthsen
dc.subjectpalladium electrocatalystsen
dc.subjectsilver electrocatalystsen
dc.subjectoksidacija natrijum borhidridasr
dc.subjectlegure platine i prelaznih metalasr
dc.subjectlegure platine i disprozijumasr
dc.subjectlegure nikla i retke zemljesr
dc.subjectpaladijum elektrokatalizatorisr
dc.subjectsrebrni elektrokatalizatorisr
dc.titleElektrokatalitički materijali za oksidaciju borhidridasr
dc.title.alternativeElectrocatalytic materials for borhydride oxidationen
dc.typedoctoralThesis
dc.rights.licenseBY-SA
dcterms.abstractШљукић-Паунковић, Биљана; Вујковић, Милица; Пашти, Игор; Ментус, Славко; Миликић, Јадранка; Електрокаталитички материјали за оксидацију борхидрида; Електрокаталитички материјали за оксидацију борхидрида;
dc.identifier.fulltexthttp://nardus.mpn.gov.rs/bitstream/id/21093/Disertacija.pdf
dc.identifier.fulltexthttp://nardus.mpn.gov.rs/bitstream/id/21094/IzvestajKomisije8024.pdf


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