CoB/Cu and PtCoB/Cu catalysts for borohydride fuel cells

CoB/Cu and PtCoB/Cu catalysts have been formed using the methods of electroless metal deposition and galvanic displacement. The activity of the PtCoB/Cu and CoB/Cu catalysts towards borohydride oxidation in alkaline solutions was studied by means of the cyclic voltammetry, chronoamperometry and chronopotentiometry. Optimal conditions of formation of catalysts have been determined and their electrocatalytic activity towards sodium borohydride oxidation has been evaluated. Pt nanoparticles sized 10-45 nm have been deposited on the CoB/Cu electrode. It has been determined that the PtCoB/Cu catalysts have enhanced electrocatalytic activity towards the oxidation of sodium borohydride as compared with that of Pt and CoB/Cu. Sodium borohydride oxidation current densities are ca. 10-12 and 4.1-4.5 times higher at the PtCoB/Cu catalysts with the Pt loadings in the range of 9.8 and 14.4 μ gPt cm−2 than those at pure Pt and CoB/Cu catalysts, respectively. It has been found that CoB/Cu and PtCoB/Cu catalyze the hydrolysis of sodium borohydride. These catalysts are promising materials and can be used in alkaline sodium borohydride fuel cells as anodes.