PBE+U-D2 study on facet selective gas adsorption and methane activation over oxygen terminated Cu2O surfaces

Abstract

It has been reported that Cu2O (100) is a better surface for sensing hydrocarbons compared to Cu2O (111). In order to understand the facet selectivity in hydrocarbon sensing, density functional theory calculations were performed to obtain adsorption energies of CO2, H2O, CH4 and O2 on oxygen terminated cuprous oxide surfaces and the activation energy for C–H bond dissociation. It was observed that Cu2O (111) surface has a high affinity towards H2O and CO2. Further, it was found that the activation energy for H3C-H bond dissociation on Cu2O (100) is significantly lower than that on Cu2O (111). Increased hydrophobicity and low activation energy for CH3-H bond breaking makes Cu2O (100) a better sensing surface for hydrocarbons.