催化学报 ›› 2020, Vol. 41 ›› Issue (6): 963-969.DOI: 10.1016/S1872-2067(19)63527-8

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Ru/CeO2催化剂催化苯乙烯氢甲氧基羰基化反应高选择性制备直链酯类化合物

安静华a,b, 王业红a, 张志鑫a, 张健a, Martin Gocylac, Rafal E. Dunin-Borkowskic, 王峰a   

  1. a 中国科学院大连化学物理研究所, 洁净能源国家实验室, 生物能源研究部, 辽宁大连 116023;
    b 中国科学院大学, 北京 100049;
    c 厄恩斯特·鲁斯卡电子显微与光谱学中心和彼得·格伦伯格研究所, 尤利希 52425, 德国
  • 收稿日期:2019-10-31 修回日期:2019-12-18 出版日期:2020-06-18 发布日期:2020-01-21
  • 通讯作者: 王峰
  • 基金资助:
    中国科学院战略性先导科技专项(XDB17020300);国家自然科学基金(21721004,21690084,21690080).

Linear-regioselective hydromethoxycarbonylation of styrene using Ru-clusters/CeO2 catalyst

Jinghua Ana,b, Yehong Wanga, Zhixin Zhanga, Jian Zhanga, Martin Gocylac, Rafal E. Dunin-Borkowskic, Feng Wanga   

  1. a State Key Laboratory of Catalysis, Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, Liaoning, China;
    b University of Chinese Academy of Sciences, Beijing 100049, China;
    c Ernst Ruska Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Juelich GmbH, Juelich 52425, Germany
  • Received:2019-10-31 Revised:2019-12-18 Online:2020-06-18 Published:2020-01-21
  • Contact: S1872-2067(19)63527-8
  • Supported by:
    This work was supported by the Strategic Priority Research Program of Chinese Academy of Sciences (XDB17020300), and the National Natural Science Foundation of China (21721004, 21690084, and 21690080).

摘要: 酯类化合物在工业上具有广泛应用,例如可用于合成香水、调味剂(味精)、洗涤剂和表面活性剂等.其中,烯烃的氢烷氧基羰基化反应是一种合成酯类化合物的重要方法,其低消耗、100%的原子经济性和原料的易获得等优势使其在制备酯类化合物中成为一个有效且实际可行的方法.对于该反应,文献多采用Pd或Rh的络合均相催化剂,其中控制反应过程中直链酯类化合物(L)和支链酯类化合物(B)的选择性是一项颇具挑战性的课题.虽然目前可通过配体的设计和修饰来调节,但多集中在均相催化体系,因此在选择性调变方面的研究仍很欠缺.相对于均相催化,多相催化由于产物易分离和提纯、催化剂可循环使用等优势而逐渐引起了研究者的广泛关注.在多相催化体系中,Pd负载在强酸性树脂作为催化剂已被应用于苯乙烯氢甲氧基羰基化反应,但在该反应中支链酯类化合物为主要产物.因此,寻找一个可有效改善多相反应体系中选择性问题的方法是非常有意义的.
在本研究工作中,我们分别以CeO2纳米颗粒(NP)、CeO2纳米棒(Rod)和CeO2纳米立方体为载体,利用浸渍法制备了Ru/CeO2、Ru/CeO2-rod和Ru/CeO2-cube三种催化剂,并进一步用于苯乙烯氢甲氧基羰基化反应.探究了CO压力、反应温度和反应时间对三种催化剂催化苯乙烯氢甲氧基羰基化反应的影响.结果表明,Ru/CeO2作为多相催化剂催化苯乙烯氢甲氧基羰基化反应时,苯乙烯选择性高于99%,直链酯选择性为83%,支链酯选择性为12%.机理研究表明,该反应为自由基机理.动力学分析表明,该反应的反应活化能为48.50kJ mol-1.结合三种催化剂的反应活性以及HRTEM结构表征结果可知,该反应中L/B比值与Ru的尺寸有较大关系.进一步的拉曼表征和NH3-TPD表征结果证明,Ru的尺寸与金属-载体之间的相互作用以及催化剂表面的氧空位浓度有直接关系.

关键词: 选择性, 钌/二氧化铈, 酯类化合物, 氢甲氧基羰基化反应, 烯烃, 多相催化

Abstract: Hydroalkoxycarbonylation of olefins has been considered to be one of the most attractive methods to synthesize esters. Controlling the regioselectivities of linear esters (L) and branched esters (B) is a challenging project for researchers working in this reaction. Although most of the attention has been paid to control the regioselectivity through ligand design in homogeneous catalytic systems, study in the area is still limited. Herein, Ru-clusters/CeO2 is employed as a heterogeneous catalyst for the hydromethoxycarbonylation of styrene without any additives. After optimization of the reaction conditions, the conversion of styrene is> 99% with 83% and 12% regioselectivity of linear and branched ester, respectively. By using different supports (CeO2 (nanoparticle), CeO2-rod, and CeO2-cube), three catalysts including Ru-clusters/CeO2, Ru/CeO2-rod, and Ru/CeO2-cube are prepared and applied in the reaction. Structural characterizations demonstrate that the L/B ratio is related to the Ru size of supported Ru catalysts. Further Raman characterization and NH3-TPD demonstrate that the metal-support interaction and the concentration of oxygen vacancy of the catalyst have a great influence on the Ru size. The mechanism and kinetic analysis for this reaction are also investigated in this work.

Key words: Regioselectivity, Ru-clusters/CeO2, Ester, Hydromethoxycarbonylation, Olefins, Heterogeneous catalysis