Theoretical perspective on CO oxidation over small cobalt oxide clusters

Abstract In this work, CO oxidation on oxidized cobalt oxide clusters, i.e., C o O n - O 2 ( n = 2 , 3 , 4 ) and ( Co 3 O 4 ) n - O 2 ( n = 1 , 2 ) are studied using density functional theory calculations. CO oxidation is investigated via an Eley-Rideal (ER) mechanism in which the CO molecule reacts with the pre-chemisorbed oxygen molecule on cobalt oxide clusters. The potential energy surfaces of reactions are investigated. It is observed that CO could be directly oxidized by chemisorbed oxygen on cobalt oxide clusters to form CO2. The reaction barriers are in the range of 0.19 eV to 0.28 eV, demonstrating the ability of these clusters to oxidize CO at low temperature.