Oxidation of CO Catalyzed by a Cu Cluster: Influence of an Electric Field

Adsorption ability and reaction rate are two essential parameters that define the efficiency of a catalyst. Herein, we implement density functional theory (DFT) and report that CO can be oxidized by a pyramidal Cu cluster with an associated reaction barrier E-b = 1.317 eV. In this case, our transition state calculations reveal that the barrier can be significantly lowered after superimposing a negative electric field. Moreover, when the field intensity corresponds to F= -0.010 au, the magnitude of E-b=0.698 eV is equivalent to-or lower than-those of typical catalysts such as Pt, Rh, and Pd. The superimposition of a positive field is found to enhance the release of the nascent CO, molecule. Our study demonstrates that small Cu clusters have better adsorption ability than the corresponding flat surface while the field can be used to enhance the purification of the exhaust gas.