Formation of C1 oxygenates by Activation of Methane on B, N Co-doped Graphene Surface Decorated by Oxygen Pre-covered Ir13 Cluster: A First Principles Study

Abstract

We employ density functional theory (DFT) to investigate the adsorption and dehydrogenation of methane on the BNG-Ir13 cluster at both low and high oxygen coverage. The DFT calculations show that the low-oxygen-coverage BNG-Ir13 cluster (BNG-Ir13O cluster) forms methanol and formaldehyde with a lower activation energy barrier compared to the high-oxygen-coverage BNG Ir13 cluster. Furthermore, the results reveal that the BNG-Ir13 cluster with low oxygen coverage has a higher methane adsorption energy and a lower activation energy barrier for methane dissociation compared to the high-oxygen-coverage BNG-Ir13 cluster. Quantitatively, the methane adsorption energy on the low-oxygen-coverage BNG-Ir13 cluster is -0.44 eV, and the second dehydrogenation of methane is the rate-determining step with an energy barrier of 1.24 eV, in both cases lower numbers than those observed for the high-oxygen-coverage BNG-Ir13 cluster.