Fueling an electrochemical cell for clean mobile energy

Abstract

Fuel cells are actively being developed to provide portable energy with the attractive features of zero emission, high energy density, and rapid re-fueling. In parallel to research on advanced materials for cell components, different fuel options are being investigated. Hydrogen, the most developed fuel with good reaction kinetics, is lacking satisfactory means of generation and storage. Gases reformed from carbon-containing fuels usually contain carbon monoxide, which poisons electrocatalysts in a fuel cell. While hydrogen contained in formic acid is only 4.3 % by mass, its complete release (without CO) makes it an attractive option. We present studies of hydrogen generation from formic acid in the presence of a PtRuBiOx catalyst. Dehydrogenation of formic acid proceeds in aqueous phase at room temperature without carbon monoxide formation. Hydrogen evolution kinetics show a low activation energy barrier of 37.3 kJ/mol. A hydrogen generator is shown feeding on formic acid and powering small fuel cell. Density functional theory (DFT) calculations are performed to explore the reaction mechanism.