催化学报 ›› 2022, Vol. 43 ›› Issue (8): 2034-2044.DOI: 10.1016/S1872-2067(21)64021-4

• 桥连热、光、电催化的表界面化学专栏 • 上一篇    下一篇

PtReOx/TiO2金属-氧化物-载体相互作用增强手性羧酸选择性加氢

高广,, 赵泽伦,, 王嘉, 席永杰, 孙鹏(), 李福伟()   

  1. 中国科学院兰州化学物理研究所, 羰基合成与选择氧化国家重点实验室, 甘肃兰州730000
  • 收稿日期:2021-10-21 接受日期:2021-11-10 出版日期:2022-08-18 发布日期:2022-06-20
  • 通讯作者: 孙鹏,李福伟
  • 基金资助:
    国家自然科学基金(21972151);国家自然科学基金(21773271);国家自然科学基金(21902165);中科院"西部之光”交叉团队项目;兰州化物所青年合作基金(HZJJ20-05);甘肃省青年科技基金(20JR5RA557);中国科学院前沿科学重点研究计划(QYZDJSSW-SLH051)

Boosting chiral carboxylic acid hydrogenation by tuning metal-MOx-support interaction in Pt-ReOx/TiO2 catalysts

Guang Gao,, Zelun Zhao,, Jia Wang, Yongjie Xi, Peng Sun(), Fuwei Li()   

  1. State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, Gansu, China
  • Received:2021-10-21 Accepted:2021-11-10 Online:2022-08-18 Published:2022-06-20
  • Contact: Peng Sun, Fuwei Li
  • About author:Prof. Fuwei Li (Lanzhou Institute of Chemical Physics, Chinese Academy of Science) received his B.A. degree from Henan University (P. R. China) in 2000, and Ph.D. degree from Lanzhou Institute of Chemical Physics (LICP), Chinese Academy of Sciences (CAS) in 2005. Then he became a research assistant at the Institute of Process Engineering of CAS, and moved to the Department of Chemistry of the National University of Singapore in 2006 as a postdoctoral fellow. Since 2010, he has been working in State Key Laboratory for Oxo Synthesis and Selective Oxidation in LICP. He is an Excellent Young Scholar Recipient of National Natural Science Foundation of China (2015). His research interests mainly focus on the catalytic conversion of bulk oxygenates, bio-based platform molecules and waste oxygen-containing polymer into value-added oxygenates. He has published more than 100 peer-reviewed papers. He was invited as an associated editor of the 6th Editorial Board of Chin. J. Catal. in 2020.
    First author contact:

    Contributed equally to this work.

  • Supported by:
    Natural Science Foundation of China(21972151);Natural Science Foundation of China(21773271);Natural Science Foundation of China(21902165);Light of West China of the Chinese Academy of Sciences (CAS);LICP Cooperation Foundation for Young Scholars(HZJJ20-05);Natural Science Foundation of Gansu Province(20JR5RA557);Key Research Program of Frontier Sciences of CAS(QYZDJSSW-SLH051)

摘要:

醇类化合物是大宗化学品和精细化工的重要原料, 其中含手性基团的醇是医药合成的重要中间体. 相较于传统当量化学合成法, 以氢气为氢源的手性羧酸多相选择性催化加氢具有原子利用率高、经济环保等优点. 此外, 调节金属与载体之间的相互作用或引入部分还原的金属氧化物来调变金属的表面电子微环境已经成为改善催化性能的常用方法, 但是当可还原性载体、部分还原金属氧化物及金属三者共存时, 他们之间的相互作用关系及其对催化性能的影响仍不清楚.

本文通过构建Pt-ReOx/TiO2催化剂体系, 调变载体二氧化钛(TiO2)表面结构, 改变表面Pt和Re物种的电子结构, 实现了1R, 2R-环己烷二甲酸的水相高效选择加氢制备1R, 2R-环己烷二甲醇(收率为87%, 固定床寿命400 h, ee值为100%). 利用准原位X射线光电子能谱(XPS)和电子顺磁共振(EPR)、氢气程序升温还原(H2-TPR)、理论计算等手段详细研究了不同晶型TiO2载体与Pt、ReOx之间的相互作用. XPS结果表明, 载体的晶型显著影响Re物种的电子结构, 其中金红石型TiO2所负载的Re含有更高比例的Re0物种, 说明该体系中金红石型TiO2具有更强的给电子能力. 进一步通过准原位XPS、EPR和理论计算分析研究发现, 三种晶型TiO2的Ti3+/Ti4+比例及氧空位含量显著不同, 氧空位密度由高至低依次为金红石型>板钛矿型>锐钛矿型. 通过与SiO2载体负载的Pt-ReOx对比结合能, 发现金属Pt的d轨道电子通过载体TiO2转移到金属氧化物ReOx物种, 从而实现这三者之间的强电子相互作用. 利用氢气程序升温脱附(H2-TPD)和原位傅里叶漫反射红外光谱(in situ DRIFT)分析氢物种和反应中间体1R, 2R-六氢苯酞在不同TiO2晶型负载Pt-ReOx催化剂表面的吸附特性. 动力学分析表明, 中间产物1R, 2R-六氢苯酞加氢至1R, 2R-环己烷二甲醇是1R, 2R-环己烷二甲酸加氢的决速步, 因此金红石型TiO2对氢物种的弱吸附以及对关键中间体的强吸附使得Pt-ReOx/TiO2(金红石)催化剂显示出最优的加氢催化活性. 由此可见, 相较于锐钛矿及板钛矿型TiO2, 金红石型TiO2载体通过转移Pt的电子降低其对氢物种的吸附, 同时增加Re物种的电荷密度以增强其对反应关键中间体的吸附, 实现了金属(Pt)、部分还原金属氧化物(ReOx)以及载体(TiO2)之间的三者协同催化. 同时, 该催化剂还可以高效地应用于多种二元羧酸和官能团化羧酸的选择性加氢转化中. 该工作为发展高效稳定的C‒O键和C=O键选择性加氢催化剂提供了一种新的策略.

关键词: 金属-氧化物-载体相互作用, 协同催化, 羧酸, 加氢, 含手性基团的醇

Abstract:

Engineering the surface microenvironment by tuning the binary interactions between a supported metal with a secondary metal oxide (MOx) or support has been a common method for improving the catalytic performance of supported metal catalysts. However, few studies have investigated the ternary interactions among the metal, MOx, and support. Here, we report for the first time the formation of metal-MOx-support interaction (MMSI) in reducible TiO2-supported PtReOx catalysts, affording 87% yield and 100% ee in the tandem hydrogenation of an aqueous chiral cyclohexane-1,2-dicarboxylic acid into the corresponding diol; the catalytic activity is eight times higher than that obtained with non-reducible support counterparts in the same reaction via traditional batch synthesis with multiple steps and unfriendly reagents. Detailed experimental and computational studies suggest that the TiO2 crystalline phase-dependent density of the oxygen vacancies induces different Pt-ReOx-TiO2 interactions, which dominate the electron transfer therein and tune the adsorption strength of the carbonyl moiety of the substrate/intermediate, thus promoting the hydrogenation activity and selectivity. In addition, the strong MMSI endows the optimal rutile TiO2 supported PtReOx catalyst with an outstanding lifetime of 400 h in a fixed-bed reactor under acidic aqueous conditions and ensures efficient applications in the selective hydrogenation of aliphatic dicarboxylic acids and functional carboxylic acids. This work provides a promising strategy for the development of efficient and stable supported catalysts for the selective hydrogenation of diverse C-O and C=O bonds.

Key words: Metal-MOx-support interaction, Synergistic catalysis, Carboxylic acid, Hydrogenation, Alcohols with chiral group