Density Functional Theory Study for Catalytic Activation and Dissociation of CO2 on Bimetallic Alloy Surfaces

Abstract

CO 2 has a potentially bright future as a carbon resource because it is very cheap and abundant. The conversion technology of CO 2 into useful chemicals therefore has gained growing attention over recent years. Despite many attempts, there have not yet been revolutionary successes for commercialization of such technology. One of the main challenges in this field is to catalytically activate the CO 2 molecule on the surfaces of catalysts. Although many researchers have studied the catalytic reactions involving CO 2 on the surfaces, the activation process of CO 2 is still controversial. Here, we performed density functional theory calculations to understand the CO 2 activation and dissociation on a wide range of bimetallic alloy surfaces. To begin with, the adsorption process of CO 2 on pure metal surfaces was carefully examined with the analyses of adsorption energetics, geometries, vibrational frequencies, charge transfers, and density of states. From the activated CO 2 on the surfaces, we could precisely capture the transition state of the dissociation reaction. On the basis of the information, we found that Brønsted–Evans–Polanyi (BEP) relations hold for CO 2 dissociation reaction. It was also verified that the sum of adsorption energies of CO and O is linearly scaled with not only adsorption energy of CO 2 δ− but also reaction energy for the CO 2 dissociation. As a result, the energy barriers of CO 2 dissociation on pure metal and bimetallic alloy surfaces could be rapidly screened by combining the BEP relation, scaling relation, and surface mixing rule. Our results will provide useful insight into designing transition metal catalysts for the CO 2 -involved reactions.