Probing the Atomistic Reaction Pathways in CuO/C Catalysts

CuO/C catalysts have been used in the selective catalytic reduction of NO because of the exceptional low-temperature denitration (de-NO) activity. A fundamental understanding of the reaction between CuO and C is critical for controlling the component of CuO/C and thus optimizing the catalytic performance. In this study, a transmission electron microscope equipped with an in situ heating device was utilized to investigate the atomic-scale reaction between CuO and C. We report two reaction mechanisms relying on the volume ratio between C and CuO: (1) The reduction from CuO to Cu₂O (when the ratio is < ∼31%); (2) the reduction of CuO into polycrystalline Cu (when the ratio is > ∼34%). The atomistic reduction pathway can be well interpreted by considering the diffusion of O vacancy through the first-principle calculations. The atomic-scale exploration of CuO/C offers ample prospects for the design of industrial de-NO catalysts in the future.