Photothermal Catalyst Engineering: Hydrogenation of Gaseous CO 2 with High Activity and Tailored Selectivity.

This study has designed and implemented a library of hetero-nanostructured catalysts, denoted as Pd@Nb2 O5 , comprised of size-controlled Pd nanocrystals interfaced with Nb2 O5 nanorods. This study also demonstrates that the catalytic activity and selectivity of CO2 reduction to CO and CH4 products can be systematically tailored by varying the size of the Pd nanocrystals supported on the Nb2 O5 nanorods. Using large Pd nanocrystals, this study achieves CO and CH4 production rates as high as 0.75 and 0.11 mol h-1 gPd -1 , respectively. By contrast, using small Pd nanocrystals, a CO production rate surpassing 18.8 mol h-1 gPd -1 is observed with 99.5% CO selectivity. These performance metrics establish a new milestone in the champion league of catalytic nanomaterials that can enable solar-powered gas-phase heterogeneous CO2 reduction. The remarkable control over the catalytic performance of Pd@Nb2 O5 is demonstrated to stem from a combination of photothermal, electronic and size effects, which is rationally tunable through nanochemistry.