Effect anions on the hydrogenation of nitrobenzene over N-rich Poly(ionic liquid) supported Pd catalyst

Abstract

In this work, N-rich ionic liquid based on 1,3,5-triimidazole triazine was used to construct poly(ionic liquid) (PIL) through free radical polymerization, and support palladium nanoparticles (Pd NPs), which were used in the catalytic hydrogenation of nitrobenzene. The resulting N-rich PIL had a good dispersion effect and ultrafine Pd NPs as shown by SEM and TEM, thereby significantly enhancing the stability of the loaded metal NPs. The XPS results indicated that the metal-support interaction improved the catalytic performance of the catalyst. In particular, the effects of different anions (Tf2N-, PF6-, and Cl-) on the PILs were investigated, and the results showed that the Tf2N anion exhibited the best catalytic effect on the hydrogenation of nitrobenzene. Furthermore, density functional theory calculation confirmed that anions played a key role in activating the substrate in the hydrogenation of nitrobenzene. The corresponding results were consistent with the experimental results, which provided reference and research for the application of PILs in the future.