Origin of Anomalous Activities for Electrocatalysts in Alkaline Electrolytes
Contribuinte(s) |
UNIVERSIDADE DE SÃO PAULO |
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Data(s) |
06/11/2013
06/11/2013
2012
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Resumo |
Pt extended surfaces and nanoparticle electrodes are used to understand the origin of anomalous activities for electrocatalytic reactions in alkaline electrolytes as a function of cycling/time. Scanning tunneling microscopy (STM) of the surfaces before and after cycling in alkaline electrolytes was used to understand the morphology of the impurities and their impact on the catalytic sites. The nature of the contaminant species is identified as 3d-transition metal cations, and the formation of hydr(oxy)oxides of these elements is established as the main reason for the observed behavior. We find that, while for the oxygen reduction reaction (ORR) and the hydrogen oxidation reaction (HOR) the blocking of the sites by the undesired 3d-transition metal hydr(oxy)oxide species leads to deactivation of the reaction activities, the CO oxidation reaction and the hydrogen evolution reaction (HER) can have beneficial effects from the same impurities, the latter being dependent on the exact nature of the adsorbing species. These results show the significance of impurities present in real electrolytes and their impact on electrocatalysis. Office of Science, Office of Basic Energy Sciences, Division of Materials Science, U.S. Department of Energy [DE-AC02-06CH11357] Office of Science, Office of Basic Energy Sciences, Division of Materials Science, U.S. Department of Energy Chemical Sciences and Engineering Division at Argonne National Laboratory Chemical Sciences and Engineering Division at Argonne National Laboratory CAPES CAPES FAPESP FAPESP |
Identificador |
JOURNAL OF PHYSICAL CHEMISTRY C, WASHINGTON, v. 116, n. 42, supl. 1, Part 3, pp. 22231-22237, OCT 25, 2012 1932-7447 http://www.producao.usp.br/handle/BDPI/42084 10.1021/jp3075783 |
Idioma(s) |
eng |
Publicador |
AMER CHEMICAL SOC WASHINGTON |
Relação |
JOURNAL OF PHYSICAL CHEMISTRY C |
Direitos |
closedAccess Copyright AMER CHEMICAL SOC |
Palavras-Chave | #OXYGEN REDUCTION #OXIDE FORMATION #CO OXIDATION #ELECTRODES #ADSORPTION #EVOLUTION #PT(111) #IMPACT #MEDIA #CHEMISTRY, PHYSICAL #NANOSCIENCE & NANOTECHNOLOGY #MATERIALS SCIENCE, MULTIDISCIPLINARY |
Tipo |
article original article publishedVersion |