Pt/C electrocatalysts with different Pt particle sizes (3～8 nm) were prepared using the impregnation-reduction method with H2[PtCl6] as precursor and vulcan XC-72 carbon black as support. The prepared Pt/C catalysts were used to evaluate the size effect of Pt on the kinetics of fuel cell reactions in the real catalyst layer of proton exchange membrane fuel cell (PEMFC) using a modified PEMFC single cell. The results indicate that the size of Pt nanocatalyst has significant impacts on the kinetics of hydrogen oxidation reaction (HOR) and oxygen reduction reaction (ORR) in the catalyst layer of PEMFC. With decreased Pt particle size, the specific activities of HOR and ORR decrease.

Key words: Pt/C catalyst, impregnation-reduction method, particle size effect, PEMFC