Hydrogen Evolution Reaction of Ammonium Borane at Bimetal Atoms Supported by Porous G-C3n4 Surface: Mechanistic Insights from Theoretical Studies

Abstract

In this study, we employ density functional theory (DFT) to explore the structural properties of g-C3N4 and its bimetallic modified catalysts by introducing the bimetallic atoms (Rh@Pt, Ru@Pd, Pd@Pt, Ru@Pt, Ph@Pd) to the g-C3N4 surface. In addition, we explore three potential reaction pathways catalyzed by these six catalysts for the dehydrogenation reaction of ammonia borane. We find the optimal reaction pathway by comparing the activation energy of the rate-limiting steps in several reaction paths. Our findings demonstrate that bimetal Rh@Pt, Ru@Pd, Pd@Pt, Ru@Pt, Ph@Pd supported by g-C3N4 can enhance catalytic activity of ammonia borane hydrogen evolution. We also investigate the reasons contributing to the improved catalytic activity of these five modified catalysts and find that Rh@Pt supported by g-C3N4 exhibits the best catalytic performance. Additionally, we study the band structure and density of states (DOS) of six catalysts and observe an increased degree of metallicity in the modified catalysts. Overall, we establish the correlation between the reaction activities of ammonia borane hydrogen evolution and the physical properties of the catalysts. This work is intended to provide a theoretical basis for optimizing catalysts for the dehydrogenation reaction of ammonia borane.

Keywords: Ammonia borane, Hydrogen evolution, DFT, Bimetallic modified catalysts, g-C3N4, Reaction mechanism