Electrochemical catalytic mechanism of single transition metal atom embedded BC3 monolayer for oxygen reduction and evolution reactions

The graphene embedded with single transition metal (TM) atom shows great potential to replace precious metals as the electrochemical catalyst of fuel cells and metal-air batteries. However, the electrochemical catalytic mechanism of single TM atom supported on other substrates is less well understood. Herein, a density functional theory calculation of single 3d TM atom embedded on two-dimensional BC3 as an active site for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is performed. The electronic structure analysis reveals that the hybridized antibonding orbitals formed by TM-3d and O-2p orbitals possess lower energy level and higher occupancy, weakening the interaction between OH and TM, further determines the catalytic activity of TM-N-4 active site. Among all considered active sites, the Fe-N-4 and Mn-N-4 sites show the best ORR catalytic performance while Co-N-4 site shows the best OER catalytic performance. Finally, an adsorption factor is put forward via the coordination environment around TM atom to provide a guidance on the exploration of new high-performance single atom catalysts family.

Automated summary

The study investigates the catalytic performance of single transition metal atoms embedded in two-dimensional BC3 as active sites for ORR and OER, revealing that Fe-N-4 and Mn-N-4 sites exhibit the best ORR catalytic performance, while Co-N-4 site shows the best OER catalytic performance. Through electronic structure analysis and the proposal of an adsorption factor, guidance is provided for the exploration of new high-performance single atom catalysts.