Methane Chemisorption on Oxide-Supported Pt Single Atom

Methane chemisorption has been recently demonstrated on the rutile IrO₂(110) surface. However, it remains unclear how the general requirements are for methane chemisorption or complexation with a single atom on an oxide surface. By exploring methane adsorption on Pt₁ substitutionally doped on many rutile-type oxides using hybrid density functional theory, we show that the occupancy of the Pt d_z² orbital is the key to methane chemisorption. Pt single atom on the semiconducting or wide-gap oxides such as TiO₂ and GeO₂ strongly chemisorbs methane, because the empty Pt d_z² orbital is located in the gap and can effectively accept σ-electron donation from the methane C−H bond. In contrast, Pt single atom on metallic oxides such as IrO₂ and RuO₂ does not chemisorb methane, because the Pt d_z² orbital strongly mixes with the support-oxide electronic states and become more occupied, losing its ability to chemisorb methane. This study sheds further light on the impact of the interaction between a Pt single atom and the oxide support on methane adsorption.