Screening of transition metal doped two-dimensional C2N (TM-C2N) as high-performance catalyst for the non-oxidative propane dehydrogenation

Abstract

Since last decade, single atom catalysts have massive development in the field of propane dehydrogenation (PDH). In this study, both the catalytic activity and reaction mechanism of 3d, 4d, and 5d transition metal atom anchored on C2N (TM-C2N) for non-oxidative PDH are studied in detail using the density functional theory methods. Firstly, six stable catalysts (Cr-, Mn-, Fe-, Co-, Cu-, and Ag-C2N) are screened out by calculating the difference between the formation energy of the single atom and the cohesive energy of the corresponding bulk metal. Combining the results of adsorption energy and density of states, it is demonstrated that propane and propylene can be stably adsorbed on all screened TM-C2N. The calculated activation barrier and reaction energy of elementary reactions involved in PDH indicate that the initial C−H bond breaking step is determined as the rate-determining step on almost all the screened TM-C2N catalysts. Among all studied TM-C2N, the Fe-C2N possesses excellent catalytic activity even better than other promising catalysts. In addition, the d-band center values of transition metal atoms in screened TM-C2N show a stronger liner relationship with the interaction energy, suggesting that the d-band center may be served as a priority descriptor for the interaction energy between reaction species and catalyst surface rather than for the adsorption energy of reaction species.