Pd nanoparticles decorated ZIFs/polymer core-shell nanofibers derived hierarchically porous N-doped carbon for efficient catalytic conversion of phenol

Abstract

The phenol hydrogenation is a green strategy for preparing cyclohexanone. The key challenge is to develop efficient catalysts. Herein, composite carbon nanofibers (CNFs) with a core-shell structure were fabricated, where ZIF-L-Co/PAN composite nanofibers were prepared by electrospinning and in-situ growth, and used as the precursor. The Pd@CNFs catalysts were synthesized by the Pd loading and applied for the phenol hydrogenation. The as-fabricated Pd@CNFs-0.3 catalyst shows superior catalytic performance, and its turnover frequency (TOF) is 59.5 h−1, which is 2.3 times that of the PAN-derived Pd@CNFs-0 catalyst and 4.9 times that of the powdered ZIFs-derived Pd@CN-0.3 catalyst. The synergistic effect of carbon nanofibers core and ZIFs-derived shell layer carbon leads to high Pd loading, enhanced phenol adsorption capacity, and fast electron and mass transfer, which together contribute to the superior catalytic performance of Pd@CNFs-0.3. Moreover, because of the unique one-dimensional nanofiber structure, Pd@CNFs-0.3 shows good recovery and reusability in the phenol hydrogenation.