Photothermal catalytic CO2 hydrogenation with high activity and tailored selectivity over monodispersed Pd-Ni nanoalloys.

Bimetallic nanomaterials exhibited excellent catalytic performance in photothermal CO2 hydrogenation due to the synergistic effect between the two metal components. However, the component-performance relationship remains unclear, which hinders the design of efficient bimetallic catalysts and the investigation of catalytic reaction mechanism. Here we illustrate the influence of the composition of binary alloy on their performance of photothermal catalytic CO2 hydrogenation by using monodispersed Pd-Ni nanocrystal as an example. Our study reveals that Ni and Pd play significantly different role in the catalytic processes. Higher Ni component in the catalysts could lead to a stronger light absorption, higher activity, but lower CO selectivity. The optimized Pd4Ni1-SiO2 catalyst exhibited a near-unity and stable CO production rate of 230 mmol·g-1·h-1 under 25-sun illumination. This study paves the way for the usage of bimetal in photothermal CO2 catalysis towards more efficient solar-to-chemical energy conversions, and sheds light on some general design principles of bimetallic catalysts to balance the intrinsic properties of individual components.