C1s CEBEs of Hydrocarbons on Elemental Oxides. II. The Adsorption Type of CH4 on the MgO Cluster

Abstract

Experimental C1s core-electron binding energy (CEBE) of hydrocarbons, alcohols or organic acids, which contain C n H 2n+1 -functional group, on MgO is determined as 286.5 eV. The value is larger than 285.0 eV as the standard value relative to the C1s CEBE of polyethylene. We discuss the physisorption type of CH 4 on the MgO clusters from theoretical viewpoints of both ab initio molecular orbital (MO) and density-functional theory (DFT) calculations. We try to indicate whether the organic molecules physisorb on MgO, or not, using accurate computational results of CEBE by the DFT calculation.