Improvement of the Borohydride Oxidation Reaction by Electrocatalysis on Pt/[TaOPO4/VC

Abstract

We study whether the borohydride oxidation reaction (BOR) on Pt is improved when the Pt is supported on tantalum oxyphosphate-Vulcan carbon (Pt/[TaOPO4/VC]). Pt on carbon (Pt/C) is unstable in the alkaline conditions at the fuel cell anode. The support is employed to improve stability, and mitigate poisoning of the Pt from BOR intermediates. BOR measurements on the Pt/[TaOPO4/VC] by rotating disk electrode (RDE) voltammetry show that the Pt/[TaOPO4/VC] is more poison-resistant than Pt/C when the NaBH4 concentration is high (0.10 M). The Pt/[TaOPO4/VC] is also incorporated at the anode of a hydrogen peroxide direct borohydride fuel cell (H2O2-DBFC). At NaBH4 anode concentrations of 0.1 M NaBH4, the DBFCs with Pt/[TaOPO4/VC] anodes have higher specific activity than those with Pt/C, particularly at 60oC.