The role of coordination-unsaturated Cu1-O3 species in the single-atom catalyst Cu/In2O3 for the preparation of acetic acid from methane and carbon dioxide

•We found that Cu/In2O3 exhibits significant advantages in methane dehydrogenation and C-C coupling due to its coordination-unsaturated Cu1-O3 species.•We observed that the doping of transition metal M resulted in a significant enhancement in the catalytic activity of methane dehydrogenation, effectively activating previously In active sites on the surface and facilitating the reaction of methane dehydrogenation.•Two types of H proton migration, the "И" type and the "n" type, were compared in their contribution to the formation of acetic acid.•Based on the computational results obtained from DFT calculations, we conducted microkinetic modeling and found that the formation of acetic acid on the Cu/In2O3 surface exhibits a stronger advantage compared to methyl formate.