Toward High Activity and Durability: An Oxygen-Rich Boron Nitride-Supported Au Nanoparticles for 4-Nitrophenol Hydrogenation

Catalytic hydrogenation of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) is widely recognized as one of the most effective solutions to deal with the water-related environmental issues, where catalysts with high activity and long cycle life are always pursued. In this paper, oxygen-rich boron nitride (BNO)-supported Au nano particles (Au/BNO) were proposed to serve as catalysts for 4-NP hydrogenation. Our results show that the Au nanoparticles are well dispersed on the highly porous BNO substrate with a small particle size of 2.2 nm. Under the optimal reaction conditions, the 4-NP molecules could be completely reduced to 4-AP in 2.5 min over Au/BNO with a relatively high conversion rate constant of 2.25 min(-1). Moreover, the as-synthesized Au/BNO is also highly stable with no visible efficiency decay after been reused for several times. The excellent durability of the catalyst could be ascribed to the strong anchoring strength between the Au nanoparticles and BNO substrate, leading to a negligible metal loss or particle agglomeration upon cycling. The role of O heteroatoms in promoting the activity and durability of the Au/BNO catalyst was further confirmed by first-principles calculations. Our simulation results indicate that the high activity of Au/BNO could be attributed to the strong pi-pi attraction between BNO and 4-NP, which facilitates the fast diffusion of 4-NP molecules to the surface of Au/BNO. The long cycle life of Au/BNO is correlated to the partially destroyed electronic conjugation of the substrate, leading to a relatively strong coordination interaction between BNO and the Au atom to stabilize the metal nanoparticles.