Pt-Ru catalysts supported on carbon xerogels for PEM fuel cells

• Tipo: Artigo em Revista Científica Internacional
• Data: 2012

Autores

J.C. Calderón (Autor) Outra; Nagendranath Mahata (Autor) FEUP; Manuel Fernando R Pereira (Autor) FEUP; José Luís Figueiredo (Autor) FEUP; V.R. Fernandes (Autor) Outra; C.M. Rangel (Autor) Outra; L. Calvillo (Autor) Outra; M.J. Lázaro (Autor) Outra; E. Pastor (Autor) Outra

Revista

Título: International Journal of Hydrogen Energy

Vol. 37

Páginas: 7200-7211

ISSN: 0360-3199

Editora: Elsevier

Indexação

ISI Web of Knowledge - 33 Citações

ISI Web of Science

Scopus - 39 Citações

Classificação Científica

FOS: Ciências da engenharia e tecnologias

Outras Informações

ID Authenticus: P-002-B9P

DOI: 10.1016/j.ijhydene.2011.12.029

Abstract (EN): Pt-Ru electrocatalysts supported on carbon xerogels were synthesized by reduction of metal precursors with formate ions (SFM method). The carbon xerogel was chemically and heat treated in order to evaluate the different procedures to generate oxygenated groups on the surface. Temperature-programmed desorption (TPD) of xerogels showed that heat treatment of previously chemically modified support gradually removes the oxygenated groups from the carbon surface. Physical characterization of the catalyst was performed using X-ray dispersive energy (EDX) and X-ray diffraction (XRD) techniques. Results confirmed that Pt-Ru catalysts with similar metal content (20%) and atomic ratios (Pt:Ru 1:1) were obtained. The electrochemical activity was studied by cyclic voltammetry. Higher CO and methanol oxidation current densities were found for catalyst deposited on chemically treated carbon xerogel when compared with the untreated material, whereas the heat treatment of carbon supports was in detriment of the catalytic activity. Gas diffusion electrode preparation and MEA assembly allowed an in-house built direct methanol fuel cell to evaluate the performance of synthesized catalysts and supports. Polarization curves were measured and confirmed the data obtained from cyclic voltammetry regarding the negative effect of heat treatment on the catalytic activity of these materials. Normalized power density curves and maximum cell power per Pt weight are discussed in terms of the operational temperature for the different materials, in comparison with results obtained with a commercial catalyst. Moreover, relationship between catalytic activity and oxygenated surface groups was established and it seems that carboxylic groups play a key role in this respect. Copyright

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 12