Direct cleavage of C=O double bond in CO by the subnano MoO surface on MoN.

Compared to H-assisted activation mode, the direct dissociation of CO into carbonyl (*CO) with a simplified reaction route is advantageous for CO-related synthetic processes and catalyst upgrading, while the stable C = O double bond makes it very challenging. Herein, we construct a subnano MoO layer on the surface of MoN, which provides a dynamically changing surface of MoO↔MoO (x < 3) for catalyzing CO hydrogenation. Rich oxygen vacancies on the subnano MoO surface with a high electron donating capacity served as a scissor to directly shear the C = O double bond of CO to form CO at a high rate. The O atoms leached in CO dissociation are removed timely by H to regenerate active oxygen vacancies. Owing to the greatly enhanced dissociative activation of CO, this MoO/MoN catalyst without any supported active metals shows excellent performance for catalyzing CO hydrogenation to CO. The construction of highly disordered defective surface on heterostructures paves a new pathway for molecule activation.