High-Performance, Scalable, and Low-Cost Copper Hydroxyapatite for Photothermal CO2 Reduction

Catalytic reduction of carbon dioxide is a promising strategy for mitigating global carbon emissions. In particular, the abundant and nontoxic material hydroxyapatite demonstrates high activity at a low cost when its constituent cations are replaced with transition metals, which also enables its catalytic properties to be tailored. Using this method, the facile and scalable synthesis of a copper-substituted hydroxyapatite catalyst is presented, demonstrating its high activity in the reverse water gas shift reaction. Thorough in situ characterization using X-ray absorption and Fourier transform infrared spectroscopic methods provides unrivaled insight into both the structure of the active catalyst and the speciation of reaction intermediates. It is thus shown that this copper-substituted hydroxyapatite catalyst is an exemplary candidate for use in large-scale carbon dioxide reduction systems.