PtM/CNT (M = Mo, Ni, CoCr) Electrocatalysts with Reduced Platinum Content for Anodic Hydrogen Oxidation and Cathodic Oxygen Reduction in Alkaline Electrolytes

Abstract

Bimetallic catalysts containing platinum and transition metals (PtM, M = Mo, Ni, CoCr) were synthesized on carbon nanotubes (CNTs) functionalized in an alkaline medium. Their platinum content is 10–15% by mass. PtM/CNTNaOH are active in both the hydrogen oxidation reaction (HOR) and the oxygen reduction reaction (ORR) in alkaline electrolytes. Although catalysts based on a single transition metal are inactive in the HOR, their activity in the cathode process of ORR increases relative to CNTNaOH. When using the rotating ring-disk electrode method for ORR, PtM/CNT showed a high selectivity in reducing oxygen directly to water. In HOR, the PtM/CNT catalyst had an activity comparable to that of a commercial monoplatinum catalyst. The results obtained show that it is possible to use the PtM/CNT catalyst in an alkaline fuel cell both as an anode and as a cathode.

Keywords

• bimetallic catalyst
• carbon nanotubes (CNT)
• hydrogen electrooxidation
• oxygen electroreduction
• alkaline electrolyte