Constructing PdZn alloy in Pd/ZnO catalyst for selective hydrogenation of anthracene to symmetrical octahydroanthracene

Selective hydrogenation is an effective approach to utilize coal tar and slurry oil to produce high value-added fine chemicals. However, how to efficiently improve the selectivity of the target product and the stability of the catalyst is difficult. Herein, the PdZn alloy catalyst was synthesized by the assistance of strong interaction between active metal (Pd) and support (ZnO) for hydrogenation of anthracene to symmetrical octahydro anthracene (sym-OHA). The PdZn alloy catalyst reduced at 400 °C was found to exhibit a 100% conversion of the anthracen with 84.77% selectivity to sym-OHA under the optimized conditions (200 °C, 1 MPa). The characterization analysis indicated that the PdZn alloy with electron-rich Pd active sites is more efficient in the selective hydrogenation than the pure Pd metal. The study of the deep hydrogenation of sym-OHA (Hydrogenation of sym-OHA to perhydroanhtracene) showed that PdZn alloy catalysts were inactive to further hydrogenation of sym-OHA. Additionally, due to the strong interaction between Pd and ZnO, the Pd/ZnO(400) catalyst shows high stability for five cycles. These findings are of practical significance for the selective hydrogenation of polycyclic aromatic hydrocarbons (PAHs) to produce high value-added products.