Enhanced catalytic CO oxidation by Cu13-mNim (m = 0, 1, 13) clusters at ambient temperatures with more active sites and distinct mechanistic pathways

Abstract

Nowadays, developing highly efficient, stable and low cost catalysts is generally considered to be the key to solve the drastically increasing of carbon monoxide (CO) emission. In this paper, Cu13-mNim (m = 0, 1, 13) bimetallic clusters have been proposed as new cluster catalysts, and their electronic, chemical properties and CO catalytic oxidation reaction are systematically calculated by DFT theoretical simulation. When an O2 molecule is adsorbed on the active-site of Cu13-mNim cluster, O2 molecule decomposing reaction occurs firstly, rather than coadsorption of O2 and CO molecule, which is modified the traditional Langmuir - Hinshelwood (LH) mechanism. By analyzing the reaction energy barrier of each step on Cu13-mNim clusters, the rate - determining step is determined as the oxidation reaction between a dissociated oxygen atom and carbon monoxide, which is hindered by a significant activation barrier. In addition, microkinetics simulations predict that Cu12Ni cluster is extremely efficient in catalyzing CO oxidation. Our findings present a rational way for designing heterogeneous catalysts with abundant reactive sites.