Recent Progress in the Development of Molecular Electrocatalysts for Formate Oxidation

Abstract

Fuel cells based on renewable synthetic fuels are promising alternatives to fossil fuel combustion for efficient electricity production. Much focus has been placed on hydrogen as a chemical fuel, but being a flammable gas, there are challenges with its safe handling. Formic acid is an attractive liquid fuel for use in direct formic acid or formate fuel cells, and it can in principle be produced from the thermal or electrochemical reduction of carbon dioxide. Over the past ten years, advances have been made in the development of molecular catalysts for the electrochemical oxidation of formate, relevant to direct formic acid or direct formate fuel cells. In this review, we present the current state of the field for molecular catalysts that promote electrochemical formate oxidation. We highlight the activity and mechanism of each system, and comment on future directions in catalyst design.