Catalytic CO2 reduction by palladium-decorated silicon–hydride nanosheets

Heterogeneous conversion of CO2 to fuels by Si surface hydrides has recently attracted broad research interest. Being earth-abundant, low-cost and non-toxic, elemental Si is a very attractive candidate for this process, which targets CO2 conversion to synthetic fuels on a gigatonne-per-year scale. It is well known, however, that silicon hydrides react stoichiometrically with CO2, and all attempts have failed to achieve catalytic conversion. The problem originates from the formation of inactive silanols and siloxanes with permanent loss of Si hydrides. Here, we deposit Pd on the surface of Si nanosheets, aiming to address the core of the problem. An operando infrared study shows Si hydrides successfully regenerating on such surfaces exposed to CO2 and H2. We demonstrate that silicon–hydride nanosheets decorated with Pd nanoparticles can enable the reverse water–gas shift reaction in a catalytic cycle. Silicon–hydride materials are attractive candidates for the photoreduction of carbon dioxide into fuels, although they have only worked stoichiometrically so far. Now, Ozin and co-workers show how decorating silicon nanosheets with palladium nanoparticles renders the process catalytic.