Preparation and catalytic performance study of Pd-Au bimetallic catalysts supported on polyaniline-derived nitrogen and phosphorus co-doped carbon for the selective hydrogenation of p-chloronitrobenzene

In this paper, an efficient catalyst (0.05 %Pd-0.5 %Au/NPC) was prepared by supporting Pd-Au bimetallic nanoparticles on a phytic acid-doped polyaniline-derived N/P co-doped carbon (NPC) support. The catalytic performance of 0.05 %Pd-0.5 %Au/NPC for the p-chloronitrobenzene (p-CNB) hydrogenation to p-chloroaniline (p-CAN) was systematically evaluated. Experiments demonstrated that the introduction of trace amounts of Pd significantly enhanced the conversion rate of the Au-based catalyst while maintaining good selectivity. The NPC support optimized the dispersion and surface electronic states of the metal nanoparticles by enhancing the metal-support electronic interaction, enabling the catalyst to achieve complete p-CNB conversion with a good selectivity (>98 %) under conditions of 100 °C and 1.2 MPa H₂. The P doping induced an electron-deficient state on the metal surface, promoting preferential adsorption of -NO₂ groups in p-CNB and desorption of -NH₂ of products p-CAN, thereby improving catalytic efficiency. This paper provides a new strategy for developing efficient and environmentally friendly catalysts for the hydrogenation of halonitroaromatics and offers a novel method for regulating the electronic structure of noble metals in carbon-based noble metal catalysts.