超临界条件下CO_2和丙烯直接合成甲基丙烯酸Ni_2(OCH_3)_2/SiO_2催化剂  

Synthesis of Methacrylic Acid from CO_2 and Propylene on Ni_2(OCH_3)_2/SiO_2 Catalyst under Supercritical Condition

作　　者：程庆彦[1] 钟顺和[1] 

机构地区：[1]天津大学化工学院,C1化学与化工国家重点实验室,天津300072

出　　处：《应用化学》2003年第11期1039-1043,共5页Chinese Journal of Applied Chemistry

基　　金：国家重大基础研究前期研究专项 ( 2 0 0 1CCA0 3 60 0 )资助项目

摘　　要：表面改性法制备了负载型双核金属甲氧基配合物催化剂Ni2 (OCH3 ) 2 /SiO2 ,采用IR和超临界反应技术对催化剂的表面结构、化学吸附性质和反应性能进行了研究。结果表明 ,Ni2 + 在Ni2 (OCH3 ) 2 /SiO2 中与载体SiO2 表面O2 -以双齿配位形式键合 ;CO2 在催化剂表面存在桥式吸附态和甲氧碳酸酯基物种 2种吸附态 ,丙烯则只有 1种分子吸附态 ;在超临界的条件下 ,CO2 和丙烯在Ni2 (OCH3 ) 2 /SiO2 催化剂上可以近 1 0 0 %选择性合成甲基丙烯酸 ;确定了Ni2 (OCH3 ) 2 /SiO2 催化丙烯与CO2 合成甲基丙烯酸的适宜反应条件为反应温度3 1 3K ,反应压力 7 5MPa,反应时间 3h。The Ni 2(OCH 3) 2/SiO 2 catalyst was prepared by surface modification reaction and ion-exchange method. The surface structure, chemisorption and reactivity of the catalyst were examined by IR and supercritical reaction. The experiment results indicated that Ni 2+is bond with surface O 2- of SiO 2 support in bidentate fashion in the supported dinuclear bridged methoxide complex Ni 2(OCH 3) 2, that the CO 2 is chemically adsorbed on the catalysts in bridged adsorption state and carbonate species and the propylene is chemically adsorbed on the catalyst in a molecular adsorption state. Under supercritical condition 313 K, 7.5 MPa and reaction time 3 h, the Ni 2(OCH 3) 2/SiO 2 catalyst gave almost 100% methacrylic acid from CO 2 and propylene in synthesis.

关 键 词：甲基丙烯酸 CO2 丙烯 超临界反应 负载型催化剂 双核桥联配合物 

分 类 号：O643[理学—物理化学]