Ensemble Effect of Ni in Bimetallic PtNi on Reduced Graphene Oxide Support for Temperature-Dependent Formic Acid Oxidation

摘要

Easy transportability, safety storage and low temperature operating conditions make direct formic acid fuel cells (DFAFCs) and direct methanol fuel cells (DMFCs) suitable alternatives to high temperature solid oxide fuel cells. These low temperature fuel cells generally use platinum or platinum-based electrocatalysts. However detrimental effect of poisonous intermediates formed during formic acid and methanol oxidations makes platinum vulnerable and led to the development of platinum based bimetallic alloy and composite electrocatalysts. In this work, we have prepared graphene supported platinum and platinum-nickel bimetallic electrocatalyst to study the catalytic activity towards formic acid oxidation. Further, we have also carried out the temperature-dependent kinetic studies of these catalysts to understand the mechanism of formic acid oxidation at various temperatures. Our findings confirmed that the ensemble effect of Ni in platinum-nickel bimetallic catalysts shows the higher catalytic activity by using a lesser amount of expensive platinum.