| Abstract
| - The electrooxidation behavior of BH4- on electrocatalytic Pt, hydrolytically active Ni, and noncatalytic Auelectrodes were comparatively reexamined and a more generalized reaction mechanism was proposed to explainthe very different anodic properties of BH4- on the different metal electrodes. In this mechanism, the anodicreaction behavior of BH4- are determined by a pair of conjugated reactions: electrochemical oxidation andchemical hydrolysis of BH4-, the relative rates of which depend on the anodic materials, applied potentials,and chemical states of the anodic surfaces. At Pt surface, the electron number of BH4- oxidation increaseswith the increased potential polarization, while the actual electron number of BH4- oxidation on Ni electrodeis 4 at most due to the poor electrocatalytic activity of the oxidized Ni surface and the strong catalytic activityof metallic Ni for chemical recombination of the adsorbed H intermediate. On the hydrolytic−inactive Ausurface, the anodic reaction of BH4- can proceed predominately through direct electrochemical oxidation,delivering a near 8e discharge capacity.
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