Efficient oxidation of CO over highly active Al-decorated nitrogenated holey 2D-graphene: A DFT perspective

•Density functional theory study is used to investigate the CO oxidation over the Al decorated C2N monolayer.•Al atom is successfully decorated over the C2N monolayer with −4.18 eV adsorption energy, confirming the stability of the system.•CO oxidation occurred via ER mechanism is more favorable with small energy barrier 0.24 eV.•The recovery of the catalyst (Al@C2N surface) is very fast and excellent.