Ultrathin In-Plane Heterostructures for Efficient CO2 Chemical Fixation

Chemical fixation of carbon dioxide (CO2) into value-added organics is regarded as a competitive and viable method in large scale industrial production, during which the catalysts with promoting CO2 activation ability are needed. Herein, we proposed an in-plane heterostructure strategy to construct Lewis acid-base sites for efficient CO2 activation. By taking ultrathin in-plane Cu2O/Cu heterostructures as a prototype, we show that Lewis acid-base sites on heterointerface can facilitate a mixed C and O dual coordination on surface, which not only strengthen CO2 adsorption, but also effectively activate the inert molecules. As revealed by in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and quasi in situ X-ray photoelectron spectroscopy (XPS), Lewis acid-base sites could readily activate CO2 to (CO2-)-C-. species, which is the key intermediate radical for CO2 fixation. As a result, abundant Lewis acid-base sites endow Cu2O/Cu nanosheets with excellent performances for dimethyl carbonate generation, a high conversion yield of 28% with nearly 100% selectivity under mild conditions. This study provides a model structure for CO2 fixation reactions.