Kinetic mechanism of effects of hydrogen addition on methane catalytic combustion over Pt(111) surface: A DFT study with cluster modeling

•Main reaction pathways are CH4→CH3∗→CH2→CH∗→CHOH∗→CHO∗→CO∗→COOH∗→CO2∗→CO2 and H2→H∗→OH∗→H2O∗→H2O.•The rate determining step of methane oxidation is the elementary reaction CH4+2∗→CH3∗+H∗.•Hydrogen and methane keep a competitive relationship on dissociative adsorption over Pt(111).