Interface‐regulated Co‐doped Pd/ ZSM ‐5 toward efficient selective hydrogenation of phenol to cyclohexanone

Abstract

Cyclohexanone serves as a crucial precursor in the chemical industry and can be produced via selective hydrogenation of phenol, a process that suffers from sluggish reaction kinetics and over‐hydrogenation to cyclohexanol. This study develops a hierarchical ZSM‐5 zeolite‐supported Pd–Co bimetallic catalyst (Pd–Co/DZ) that addresses this dichotomy through a synergistic dual‐function design. Compared with monometallic Pd, the formation of highly dispersed Pd–Co alloy substantially enhances the adsorption and activation rate of H ₂ , thereby accelerating the phenol hydrogenation. The hierarchical zeolite exploits its abundant surface defect sites to chelate Co species, generating Co–O–Si bonds. This configuration promotes the tilted adsorption of phenol while suppressing the deep hydrogenation of cyclohexanone to cyclohexanol. Leveraging the dual role of Co in the Pd/ZSM‐5 under a phenol‐to‐Pd molar ratio of 1132, a turnover frequency of 268.9 h ⁻¹ for phenol‐to‐cyclohexanone with 93.1% yield is achieved. This work provides valuable insights for the design of catalysts in the hydrogenation of phenolics.