Borohydride electrochemical oxidation on carbon-supported Pt-modified Au nanoparticles

The carbon-supported Pt-modified Au nanoparticles were prepared by two different chemical reduction processes, the simultaneous chemical reduction of Pt and Au on carbon process (A-AuPt/C) and the successive reduction of Au then Pt (B-AuPt/C) on carbon process. These two catalysts were investigated as the anode catalysts for a direct borohydride fuel cell (DBFC) and Au nanoparticles on carbon (Au/C) were also prepared for comparison. The DBFC with B-AuPt/C as the anode catalyst shows the best anode and fuel cell performance. The maximum power density with the B-AuPt/C catalyst is 112 mW cm−2 at 40 °C, compared to 97 mW cm−2 for A-AuPt/C and 65 mW cm−2 for Au/C. In addition, the DBFC with the B-AuPt/C catalyst shows the best fuel utilization with a maximum apparent number of electrons (Napp) equal to 6.4 in 1 M NaBH4 and 7.2 in 0.5 M NaBH4 as compared to the value of Napp of 8 for complete utilization of borohydride.