关键词: 苯酚, 加氢, 镍基催化剂, 环己酮, 环己醇, 还原

Abstract: Nickel-based catalysts supported on γ-A1₂O₃ or SiO₂ from Ni(NO₃)₂, NiCl₂ or NiSO₄ as precursors were prepared with incipient technique and further reduced by H₂ at high temperature. Influence of nickel precursors, catalyst supports, nickel loadings and reaction conditions on the catalytic performance of phenol hydrogenation was investigated. Among three nickel precursors studied, Ni(NO₃)₂ was the most easily reduced by H₂ and the catalyst prepared displayed the best catalytic performance. It was shown that the nickel catalyst on SiO₂ exhibited higher performance than that on γ-Al₂O₃. The reasonable nickel loading was helpful to active component dispersion and good catalytic performance. The main product on the nickel supported catalysts was not the cyclohexanone but the cyclohexanol, and yet, the selectivity of cyclohexanone could be increased under the modest reaction conditions. The reaction rate or the cyclohexanone selectivity could be improved in nonpolar solvents like heptane or cyclohexane compared to that in polar solvents, like alcohol or H₂O.

Key words: phenol, hydrogenation, nickel supported catalysts, cyclohexanol, cyclohexanone, reduction