Highly Active and Selective Hydrogenation of CO₂ to Ethanol by Ordered Pd–Cu Nanoparticles

Carbon dioxide (CO₂) hydrogenation to ethanol (C₂H₅OH) is considered a promising way for CO₂ conversion and utilization, whereas desirable conversion efficiency remains a challenge. Herein, highly active, selective and stable CO₂ hydrogenation to C₂H₅OH was enabled by highly ordered Pd-Cu nanoparticles (NPs). By tuning the composition of the Pd-Cu NPs and catalyst supports, the efficiency of CO₂ hydrogenation to C₂H₅OH was well optimized with Pd₂Cu NPs/P25 exhibiting high selectivity to C₂H₅OH of up to 92.0% and the highest turnover frequency of 359.0 h⁻¹. Diffuse reflectance infrared Fourier transform spectroscopy results revealed the high C₂H₅OH production and selectivity of Pd₂Cu NPs/P25 can be ascribed to boosting *CO (adsorption CO) hydrogenation to *HCO, the rate-determining step for the CO₂ hydrogenation to C₂H₅OH.