Formic Acid Electrochemical Oxidation on Au25 and Pt@Au24 Nanocatalysts: A DFT Approach

Electrooxidation of formic acid has been the focus of intensive investigations due to its importance in the development of low temperature fuel cells. In this work, first principles density functional theoretical calculations were carried out to examine the reaction path for the electrocatalytic oxidation of formic acid on the monolayer-protected Au₂₅ and Pt@Au₂₄ nanoclusters. The Au₂₅-nanocluster oxidizes HCOOH via an indirect pathway; first, forming CO, which can then be reoxidized to form CO₂.  On the Pt@Au₂₄ nanocluster, it proceeds either through a formate and/or direct path at lower onset potentials than Au₂₅.  The calculations present a mechanism for electrochemical experimental observations for formic acid oxidation on monolayer-protected cluster nanocatalysts.