Abstract ZIF-derived N-doped carbon (CN) materials were modified in this work by TiO2 nano-islands with oxygen vacancies (OV) through a sol-gel method and subsequent thermal treatment. By loading Pd nanoparticles (NPs) on CN@TiO2, Pd@CN@TiO2 catalysts were fabricated. Superior catalytic performance of Pd@CN@TiO2 was found in the selective phenol hydrogenation to cyclohexanone, with a TOF of 30.1 h−1, 2.2-fold as high as that of Pd@CN. The synergistic effect of CN and TiO2 nano-islands was responsible for the superior catalytic performance. More OV was generated due to the high specific surface area of CN. At the same time, CN could also enhance the hydrophilicity, and adsorb more phenol in non-planar fashion. The TiO2 nano-islands with OV could improve the Pd dispersion, make more Pd element on the support surface, strengthen the antioxidizability of Pd and induce electron-rich Pd NPs. Furthermore, the as-fabricated Pd@CN@TiO2 showed good recyclability in the phenol hydrogenation, and also exhibited excellent catalytic performance in the catalytic hydrogenation of phenol with diverse functional groups. These findings provide the feasibility of using the high-performance catalysts for the hydrogenation of phenol derivatives.

中文翻译：

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用 TiO2 纳米岛调整 N 掺杂碳的表面特性以增强苯酚氢化成环己酮

摘要 在这项工作中，通过溶胶-凝胶法和后续热处理，通过具有氧空位 (OV) 的 TiO2 纳米岛对 ZIF 衍生的 N 掺杂碳 (CN) 材料进行了改性。通过将 Pd 纳米粒子 (NPs) 负载在 CN@TiO2 上，制备了 Pd@CN@TiO2 催化剂。Pd@CN@TiO2 在苯酚选择性加氢生成环己酮时表现出优异的催化性能，TOF 为 30.1 h-1，是 Pd@CN 的 2.2 倍。CN 和 TiO2 纳米岛的协同作用是其优异催化性能的原因。由于 CN 的高比表面积，产生了更多的 OV。同时，CN还可以增强亲水性，以非平面方式吸附更多的苯酚。具有OV的TiO2纳米岛可以改善Pd的分散，在载体表面产生更多的Pd元素，增强 Pd 的抗氧化性并诱导富电子 Pd NPs。此外，制备的Pd@CN@TiO2在苯酚加氢反应中表现出良好的可回收性，并且在催化加氢具有多种官能团的苯酚中也表现出优异的催化性能。这些发现为使用高性能催化剂氢化苯酚衍生物提供了可行性。