Effective CO2 activation of enriched oxygen vacancies for photothermal CO2 methanation

Oxygen vacancies have been widely concerned with the facilitation effects of CO2 activation for CO2 methanation. However, little attention has been paid to the generation of active intermediate species induced by enriched oxygen vacancies. Herein, we discovered that CeNiO3−δ catalyst enriched oxygen vacancies can efficiently activate CO2 and realize high activity for photothermal CO2 methanation. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) proved that oxygen vacancies are beneficial to the formation of reactive intermediate species of polydentate carbonate over CeNiO3−δ, which is crucial for efficient CO2 methanation. These results revealed mechanistic insights into how effective CO2 activation induced by oxygen vacancies can be manipulated by adjusting the adsorption intermediate species.