Highly Efficient Photothermal Reduction of CO 2 on Pd 2 Cu Dispersed TiO 2 Photocatalyst and Operando DRIFT Spectroscopic Analysis of Reactive Intermediates.

The photocatalytic conversion of CO 2 to fuels using solar energy presents meaningful potential in the mitigation of global warming, solar energy conversion, and fuel production. Photothermal catalysis is one promising approach to convert chemically inert CO 2 into value-added chemicals. Herein, we report the selective hydrogenation of CO 2 to ethanol by Pd 2 Cu alloy dispersed TiO 2 (P25) photocatalyst. Under UV-Vis irradiation, the Pd 2 Cu/P25 showed an efficient CO 2 reduction photothermally at 150 °C with an ethanol production rate of 4.1 mmol g -1 h -1 . Operando diffuse reflectance infrared Fourier transform (DRIFT) absorption studies were used to trace the reactive intermediates involved in CO 2 hydrogenation in detail. Overall, the Cu provides the active sites for CO 2 adsorption and Pd involves the oxidation of H 2 molecule generated from P25 and C-C bond formation.