Ultradispersed Nickel Phosphide on Phosphorus-Doped Carbon with Tailored d-Band Center for Efficient and Chemoselective Hydrogenation of Nitroarenes

Nickel phosphide is a promising catalyst for hydrogenation of nitroarenes but suffers from sluggish H desorption and low chemoselectivity. Herein, we overcome these problems through reducing the Ni2P into subnanosized clusters, tailoring the d-band center of Ni, and coupling them with P-doped carbon. Using density functional theory (DFT) calculations, we predicted that electron transfer from P-doped carbon to Ni2P cluster results in downshift of d-band center of Ni that promotes H desorption on highly charged antibonding orbital of Ni-H, and reactant is preferentially adsorbed on P-doped carbon surface through nitro group due to the geometrical hindrance on Ni2P clusters that leads to good selectivity. Then we developed a chemical anchoring method to fabricate Ni2P supported on P-doped carbon with high dispersion of 81.3%. The synthesized catalyst delivers high activity and selectivity chemo-selective hydrogenation of nitroarenes, and outperforms various noble- and transition-metal catalysts. Moreover, we revealed the origins of the superior performance of catalyst by characterizations, and confirmed the conclusion of DFT calculation. Such concept of tailoring d-band center and improving dispersion of active phase can provide insight for design of catalysts for hydrogenation and beyond.