Frustrated Lewis Pairs Accelerating CO 2 Reduction on Oxyhydroxide Photocatalysts with Surface Lattice Hydroxyls as a Solid‐State Proton Donor

Light‐driven CO 2 reduction into high value‐added product is a potential route to convert and store solar energy. Here, using the hydroxyls on an oxyhydroxide photocatalyst, CoGeO 2 (OH) 2 , as solid‐state proton source to reduce the CO 2 into CH 4 is proposed. It is found that under irradiation, the lattice hydroxyls on surface of CoGeO 2 (OH) 2 are oxidized by photogenerated holes, resulting in the generation of oxygen vacancies (O Vs ) and protons. The photoinduced O Vs (Lewis acid) and its proximal surface hydroxyls (Lewis base) are more likely to form the frustrated Lewis acid–base pairs, which can capture, activate, and reduce CO 2 with the assistance of protons into CH 4 . The surface lattice hydroxyls are able to regenerate when the catalyst is exposed to the water molecule–containing atmosphere, thus achieving a sustainable CO 2 conversion. The proposed CO 2 reduction by self‐breathing surface hydroxyls may open a new avenue to use photocatalysis for energy conversion.