A dispersion-corrected density functional theory study is performed about reaction pathways and energy barriers of NO reduction by CO over Si-coordinated nitrogen doped graphene (SiN4-Gr). The results indicate that NO molecule can be stably chemisorbed over the Si atom of SiN4-Gr due to the favorable hybridization of Si-3p and NO-2π* states. The coadsorption of NO molecules to form absorbed (NO)2 species is proved to be the initial step for the reduction of NO molecules over the title surface. The energy barriers for the (NO)2→ N2O + O* reaction are in the range of 0.38-0.60 eV, which seem to be overcome at ambient condition. According to our findings, NO reduction over SiN4-Gr is a thermodynamically favored process at a relatively wide range of temperatures.
