Influences of carbon support on the electrocatalysis of polypyrrole-modified cobalt hydroxide in the direct borohydride fuel cell

Catalysts of Co(OH)2 supported on polypyrrole-modified Super P carbon and on polypyrrole-modified BP 2000 carbon are prepared by a chemical method. The structure and morphology of the catalysts are characterized by X-ray diffraction, X-ray photoemission spectroscopy and transmission electron microscopy. BP 2000 carbon demonstrates larger specific surface area, lower crystallization degree and lower electrochemical resistance than Super P carbon. The surface characteristics of the carbon support have notable influences on the morphology and electrocatalytic activity of Co(OH)2. Co(OH)2 distributes much homogeneously on the polypyrrole-modified BP 2000 with more polypyrrole content, and exhibits higher electrocatalytic activity compared with that on polypyrrole-modified Super P carbon. The DBFC using Co(OH)2 supported on polypyrrole-modified BP 2000 as the catalysts demonstrates fairly good performance (160 mW cm−2) under ambient conditions.