Penta-graphene as a Metal-free catalyst for CO and NO reaction -Insights from First-principles calculations

Penta-graphene, a new two-dimensional carbon allotrope, has attracted considerable attention due to its novel properties and promising applications for nanoelectronics, sensors and catalyzer. In this work, we study the adsorption behaviors of CO and NO, and their possible redox reactions on penta-graphene surface through firstprinciples calculations. The results show that CO or NO molecule is in favor of chemically adsorbing on the surface of penta-graphene after overcoming an energy barrier of 0.046 eV or 0.037 eV. More importantly, when only CO and NO molecules co-existed on penta-graphene surface, the redox reaction CO + NO -> CO2 + N, NO + N -> N2O can be realized efficiently under low temperature. The energy barrier of whole reaction is predicted to be only 0.375 eV under Eley-Rideal mechanism which is much lower than that of 0.970 eV under LangmuirHinshelwood mechanism, quite close to the CO oxidation catalyzed by noble metals. These results provide a new route not only for simultaneously catalyzing the co-existed toxic molecules but also for producing N2O through NO and CO reaction on PG surface, and it would be helpful for the potential applications of PG-based catalyzer in the future.