ZIF-8 derived N-doped porous carbon confined ultrafine PdNi bimetallic nanoparticles for semi-hydrogenation of alkynes

Abstract

Catalytic semi-hydrogenation of alkynes to alkenes plays an important role in the polymer, fragrance, medicine, and other chemical industrial fields. However, increasing the selectivity of alkenes during the semi-hydrogenation process is a huge challenge. Herein, N-doped porous carbon support (NC) was fabricated from zinc-based zeolite imidazole frameworks (ZIF-8). Ultrafine PdNi bimetallic nanoparticles (NPs) were uniformly dispersed, stably anchored on the NC support, and used as an efficient alkynes semi-hydrogenation catalyst. The synthesized Pd2Ni2/NC catalyst had a selectivity of 95.1% toward styrene and high catalytic activity (TOF=977.7 h−1) for the semi-hydrogenation of phenylacetylene under mild reaction conditions. The catalyst was mainly through metal-support interaction and electron transfer between Pd and Ni metal, modulating the electronic structure of the active sites, thus improving the selectivity of styrene. Selective hydrogenation of various substituted alkynes on Pd2Ni2/NC catalyst has also proved excellent applicability, and the obtained catalyst can be reused with favorable stability. This study adjusted the catalytic performance by adding a secondary metal, which provided a useful strategy for designing highly efficient catalysts for the semi-hydrogenation of alkynes.