Modulation of active site in CePO₄/PtCo via multiple synergistic effects for enhanced nitroaromatic hydrogenation

The hydrogenation of nitroaromatics to aromatic amines is widely applied in the chemical, pharmaceutical, and agrochemical industries. However, the high cost of traditional precious metal-supported catalysts limits their industrial development. To address this, a PtCo alloy nanoparticle catalyst supported on CePO₄ (CePO₄/PtCo) was designed. The catalyst exhibits high activity and selectivity for the hydrogenation of nitroaromatics under 60 °C and 5 bar H₂, achieving 100 % conversion of p-nitrophenol and 98.2 % selectivity to aromatic amines within 50 min. Catalytic mechanism studies indicate that the multi-level modulation of active sites is achieved through the synergistic interplay of dual mechanisms: electron transfer within PtCo alloys and metal-support interactions between PtCo and CePO₄. This multiple synergy enables precise electronic tuning of Pt sites, enhancing the adsorption capacity for nitroaromatics and reducing the reaction energy barriers of potential-determination steps. Meanwhile, the functional support CePO₄ adsorbs and activates the substrate, providing additional active sites for hydrogenation under hydrogen spillover. The multiple synergistic effects between the components of the catalyst revealed in this study provide new insights for the rational design of heterogeneous catalysts.