Effect of Platinum, Gold, and Potassium Additives on the Surface Chemistry of CdI₂-Antitype Mo₂C

摘要

Transition metal carbides are versatile materials for diverse industrial applications including catalysis, where their relatively low cost is very attractive. In this work, we present a rather extensive density functional theory study on the energetics of adsorption of a selection of atomic and molecular species on two Mo terminations of the CdI_(2) antitype phase of Mo_(2)C. Moreover, the coadsorption of CO in the presence of preadsorbed metal atoms and its dissociative adsorption in the absence and presence of preadsorbed Pt and K were investigated. By using CO as a probe to understand the structural/electronic effects of the preadsorption of the metal atoms on the Mo_(2)C(001) surface, we showed that K further enhances CO adsorption/activation on the surface, in contrast to the precious metals considered. Moreover, it was observed that the presence of both Pt and K stabilizes the transition state for the C–O bond dissociation, lowering the activation barrier for the dissociation of the C–O bond by about 0.3 and 0.4 eV, respectively.