Regulation of nitrogen reduction reaction catalytic performance by varying the sp/sp2 hybrid carbon ratio in graphyne/graphene heterojunction catalysts†

Abstract

This study investigates the impact of the sp/sp² hybrid carbon ratio on the nitrogen reduction reaction (NRR) catalytic performance of γ-graphyne and graphene-based heterojunction catalysts. Through density of states (DOS) calculations, crystal orbital Hamilton population (COHP) analysis, and charge density difference plots, it is found that the sp/sp² hybrid carbon ratio significantly influences the electronic properties and NRR activity of the catalysts. The Ti@GY1/Gr catalyst exhibits superior performance, attributed to its sensitivity to changes in the sp/sp² hybrid environment, especially when combined with graphene. An increase in the sp/sp² hybrid carbon ratio leads to a decrease in NRR activity, while also modulating the interaction between Ti and the carbon support. The findings highlight the importance of the sp/sp² hybrid carbon ratio in regulating the electronic properties and catalytic performance of heterojunction catalysts, providing insights for the design of more efficient NRR catalysts.