The Facile Dissociation of Carbon-Oxygen Bonds in CO2 and CO on the Surface of LaCoSiHx Intermetallic Compound.

In catalysis science, the electronic structure of the active site determines the structure-activity relationship of the catalyst to a large extent. Therefore, modulating the electronic structure has become a main route for the rational design of metal-based catalyst materials. In this work, we prepared a LaCoSiHx material that has more electronegativity and a lower workfunction than traditional supported Co-based catalysts. Using CO2 methanation as a model catalytic reaction, the facile dissociation of CO2 and CO (a key reaction intermediate) on the surface of the LaCoSiHx catalyst is observed by various experimental methods (e.g., in situ Raman and FTIR) at room temperature. Moreover, theoretical calculation results further show that LaCoSiHx has a much stronger capacity for carbon-oxygen bond activation than the Co surface. The intrinsic mechanism is attributed to the marked electron transfer from catalysts into the antibonding orbital of CO2 and CO.