Catalytic Mismatching of CuInSe<sub>2</sub> and Ni<sub>3</sub>Al Demonstrates Selective Photoelectrochemical CO<sub>2</sub> Reduction to Methanol
Brian M. Foster, Aubrey R. Paris, Jessica J. Frick, Daniel A. Blasini-Pérez, R. J. Cava, Andrew B. Bocarsly
Abstract
Photoelectrochemical catalysts are often plagued by ineffective interfacial charge transfer or nonideal optical conversion properties. To overcome this challenge, strategically pairing a catalytically inactive, optically proficient semiconductor with a selective electrocatalyst, coined “catalytic mismatching”, is suggested. Here, chalcopyrite semiconductor CuInSe2 is paired with the electrocatalyst Ni3Al to selectively reduce CO2. This catalytically mismatched system produces methanol at a Faradaic efficiency 25 times greater than that achieved using the purely electrochemical Ni3Al system while reducing the operating potential requirement by 600 mV. These results suggest that catalytic mismatching is a promising tactic to achieve reaction selectivity in synergistic photoelectrochemical CO2 reduction systems.