高等学校化学学报 ›› 2003, Vol. 24 ›› Issue (1): 125.

• 论文 • 上一篇    下一篇

负载型Sn2(OMe)2Cl2/SiO2催化剂的制备、表征与催化合成碳酸二甲酯

钟顺和, 程庆彦, 黎汉生   

  1. 天津大学化工学院, 一碳化学与化工国家重点实验室, 天津 300072
  • 收稿日期:2002-03-20 出版日期:2003-01-24 发布日期:2003-01-24
  • 通讯作者: 钟顺和(1938年出生),男,教授,博士生导师,从事工业催化剂设计等研究.E-mail:shzhong@public.tpt.t.jcn E-mail:shzhong@public.tpt.t.jcn
  • 基金资助:

    国家自然科学基金(批准号:20076035)资助

Preparation and Characterization of Supported Catalyst Sn2(OMe)2Cl2/SiO2 and Its Catalytic Properties for Synthesis of Dimethyl Carbonate

ZHONG Shun-He, CHENG Qing-Yan, LI Han-Sheng   

  1. College of Chemical Engineering and Technology, Tianjin University, State Key Laboratory of C 1 Chemical and Chemical Engineering, Tianjin 300072, China
  • Received:2002-03-20 Online:2003-01-24 Published:2003-01-24

摘要: 采用表面改性法制备了负载型Sn2(OMe)2Cl2/SiO2双核桥联配合物催化剂,用IR,TPD和微量反应技术研究了催化剂的表面结构、化学吸附性能和反应活性.结果表明,双核桥联配合物Sn2(OMe)2Cl2以O(Me)为桥,Cl为配体,并以Sn-O-Si形式键合到SiO2表面上;CO2与催化剂表面的金属离子Sn4+和桥基配体OMe的O2-形成桥式和甲氧碳酸酯基两种吸附态,CH3OH与催化剂表面的金属离子Sn4+仅形成一种分子吸附态;在413K以下,CO2和CH3OH在Sn2(OMe)2Cl2/SiO2催化剂表面上以近100%的选择性生成碳酸二甲酯;CO2在催化剂表面形成的甲氧碳酸酯基吸附态是生成DMC的关键物种,其与在同一活性中心的分子吸附态甲醇的反应决定了催化剂的活性和产物选择性.

关键词: 双核桥联配合物, 负载型配合物催化剂, CO2, 甲醇, 碳酸二甲酯合成

Abstract: Silica supported binuclear bridged complex Sn2(OMe)2Cl2/SiO2 was prepared by surface modification. IR, TPD and micro-reactor evaluation techniques were used to characterize the surface structure, absorption properties and reactivity of Sn2(OMe)2Cl2/SiO2. The results indicate that the Cl-is the ligands of Sn2(OMe)2Cl2/SiO2 , bis-μ-OMe bridged Sn2(OMe)2 can be formed between the two Sn4+metal ions and bonded on the surface of SiO2 by Sn-O-Si bonds; CO2 can be chemisorbed on Sn2(OMe)22/SiO2 catalyst to form bridged adsorption state and methyl carbonate species, CH3OH can be chemisorbed on the catalyst to form molecular adsorption state. At the reaction temperature 413 K, the Sn2(OMe)2Cl2/SiO2 catalyst has almost 100% DMC selectivity for DMC direct synthesis from CO2 and CH3OH. The mechanism for DMC synthesis from CO2 and CH3OH on the surface of Sn2(OMe)2Cl2/SiO2 is proposed based on the experimental results. The reactants CO2 and CH3OH co-adsorbing at the same active site on the surface of Sn2(OMe)4/SiO2 and the formation of methoxy carbonate species of CO2 on the surface of the catalyst were the critical steps for the DMC synthesis.

Key words: Binuclear bridged complex, Supported complex catalyst, CO2, CH3OH, Synthesis of dimethyl carbonate

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