The Reactivity and Deactivation Mechanism of Ru@C Catalyst over Hydrogenation of Aromatics to Cyclohexane Derivatives
Huahua Zhao, Huanling Song, Jun Zhao, Jian Yang, Liang Yan, Lingjun Chou
Abstract
Abstract Nano Ru supported on carbon catalysts with different Ru nanoparticle sizes were reported for the aromatics (dioctyl phthalate, xylene, p ‐phenylenediamine, cinnamic acid and nitrobenzene) hydrogenation to the corresponding value‐added cyclohexane derivatives. Ru@C–DP prepared by facile deposition‐precipitation strategy, exhibited the smaller Ru nanoparticle (NP) size 2.0 nm, higher Ru dispersion degree (60.2%) and larger Ru specific surface area (220.1 m 2 ⋅g Ru −1 ) than Ru@C‐EG and Ru@C–IM synthesized with ethylene glycol reduction and impregnation method, respectively. Ru@C–DP possessed excellent activity with aromatic conversion ≥ 99% and cyclohexane derivative selectivity ≥ 99%, which was attributed to its smaller Ru NP size, suggesting the presence of a size‐dependent effect. Moreover, compared with the commercial Ru@C–ID catalyst, Ru@C–DP showed remarkable reusability in aromatic hydrogenation. After the several hydrogenation recycles, the catalyst lost some activity mainly account for the pore blocking by reactant/product molecules, part oxidation and aggregation of Ru NPs.