Mechanism of formaldehyde oxidation catalyzed by doped graphene single atom catalysts: Density functional theory study

•The mechanism of HCHO oxidation by the doped single atom catalysts is studied.•The HCHO adsorption on the catalyst surfaces is revealed from the kinetic aspect.•The optimum adsorption temperature of HCHO in the Fe-doped system is 500 K.•The heat released by the reaction mainly comes from the dehydrogenation reaction.•Fe/DV-N4 can be a promising and efficient catalyst for HCHO oxidation.