Synthesis and Characterization of Eggshell-Type Pd–Ni Bimetallic Nanoparticles for Enhancing 2-MF Hydrogenation Activity

An eggshell-type structure Pd–Ni bimetallic catalysts with different ratios of Pd–Ni (Pd–Ni/Al₂O₃) were prepared by the deposition–precipitation method using spherical Al₂O₃ as a support and were first applied to the catalyst 2-methylfuran (2-MF) hydrogenation reaction. The effect of Ni loading on Pd–Ni bimetallic interactions was explored in the 2-MF hydrogenation reaction. By introducing the Ni component, both the use of the noble metal Pd is reduced and the activity of the catalyst is improved. The activity curves results was shown that the Pd–Ni/Al₂O₃ catalyst had the highest activity and stability when the ratio of the substance amounts of the Pd and Ni components was regulated to be 1.5. Reducing the reaction temperature and pressure, with a conversion and selectivity of 99.6% and 99.5%, respectively. The catalyst is highly stable and active due to the interaction of the metal carriers to produce an active electron-deficient palladium species (Pdⁿ⁺), with only a 1% decrease in conversion after 7 cycles and recovery of activity after calcination. The unique eggshell-type structure allows for selective deposition of the active components Pd and Ni in the outer regions of the spheres, enabling efficient use of the active components at high air velocities and mass transfer limit conditions. This study provides ideas for reducing the use of precious metals and offers the possibility of targeted modulation of 2-MF hydrogenation products.