Visible light-regulated thermal catalytic selectivity induced by nonthermal effects over CuNi/CeO2

Abstract

Solar-assisted photothermal catalysis is a fascinated picture of chemical and energy conversion. However, it is difficult to distinguish the nonthermal effects due to the thermal and nonthermal tend to exhibit similar experimental results. Here, we reported that the CuNi alloy deposited CeO2 (CuNi/CeO2) with visible light excited carriers at the interface can promote CO2 reduction in the photothermal catalysis. Impressively, the CuNi/CeO2 exhibit different product selectivities in the dark and visible light reactions, especially the light promoted the further hydrogenation to CH4 conversion. Detailed experiments reveal that the hot electron transfer between plasmon metal Cu and metal Ni under visible light excitation alters the pathway of thermal reduction while increasing surface hydroxyl and oxygen vacancies as CO2 trapping sites. The excessive H2 activation under visible irradiation induces the deep reduction of CO2 to CH4, instead of reverse water gas shift. Combining with in-situ DRIFTS, quasi-situ EPR, H2 pulse and DFT calculations, the nonthermal effects of CO2 reduction is proposed over CuNi/CeO2 with electrons transfer between Cu and Ni nanoparticles.