MSE Graduate Seminar: Novel Cu-P-based Electrocatalysts for the Hydrogen Evolution Reaction

ABSTRACT: With the decreasing cost of renewable energy (solar, wind), reducing the capital cost of electrolysers is key to future hydrogen generation.  Ongoing improvements in the performance of anion exchange membrane (AEM) water electrolysers have led to renewed interest in alkaline water electrolysis for commercial hydrogen production. Highly stable and active transition metal based electrocatalysts are required for incorporation in AEM water electrolysers. Cu3P and Cu-P-X alloys were prepared and evaluated as electrocatalysts for the alkaline hydrogen evolution reaction. The roles of microstructure and chemistry on catalytic activity were investigated. Characterization by X-ray diffraction identified single phase and heterogeneous phase structures in alloyed samples. Capacitance measurements at non-faradaic potentials were used to determine the electrochemically active surface area (ECSA) of the alloys in order to establish their intrinsic activity. Electrocatalytic activity was measured using Tafel and impedance spectroscopy techniques. The heterogeneous ternary Cu-P-X alloy composition displayed greater electrocatalytic activity than the pure Cu3P. This increase in electrocatalytic activity was attributed to the presence of a secondary Cu-P-X phase dispersed in a Cu3P matrix. These preliminary results demonstrate that heterogeneous Cu-P-X alloys are promising electrocatalysts for electrochemical hydrogen production.