物理化学学报 >> 1998, Vol. 14 >> Issue (11): 1013-1019.doi: 10.3866/PKU.WHXB19981110

研究论文 上一篇    下一篇

负载型水溶性铑膦配合物催化剂的结构和性能

袁友株, 张宇, 陈忠, 张鸿斌, 蔡启瑞   

  1. 厦门大学化学系，物理化学研究所，固体表面物理化学国家重点实验室，厦门 361005
  • 收稿日期:1998-02-09 修回日期:1998-06-04 发布日期:1998-11-15
  • 通讯作者: 袁友株

Structure and Hydroformylation Performance of Supported Aqueous-phase Rh Catalyst

Yuan You-Zhu, Zhang Yu, Chen Zhong, Zhang Hong-Bin, Cai Qi-Rui   

  1. Department of Chemistry,Institute of Physical Chemistry,State Key Laboratory for Physical Chemistry of Solid Surface,Xiamen University,Xiamen 361005
  • Received:1998-02-09 Revised:1998-06-04 Published:1998-11-15
  • Contact: Yuan You-Zhu

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摘要：

SiO2担载TPPTS（间-三苯基膦三磺酸钠盐）－Rh（acac）（CO）2制成的负载型水溶性催化剂进行1-己烯氢甲酰化催化反应时，引入适量水蒸气可显著提高催化活性．用魔角旋转固体核磁共振磷谱表征得到，在新制备的催化剂中，吸附于SiO2表面但未参与配位的TPPTS，约占总膦物种的70mol％以上，而位于δ=32．4处的表面配合物｛Rh（CO）（TPPTS）2｝膦物种量约为15mol％，其它膦10mol％左右．催化剂经干燥合成气在373K处理2h、或经湿合成气在较低温度（333K）下处理2h后，｛Rh（CO）（TPPTS）2｝的增加量仅约为10～15mol％，其它膦物种的变化量也较小，但催化剂经湿合成气于373K处理2h后，｛Rh（CO）（TPPTS）2｝的净增量大于40mol％；在工作态催化剂中，也观察到｛Rh（CO）（TPPTS）2）大量生成、未配位TPPTS量减小；经43h反应运转后，催化剂活性下降，归属为｛Rh（CO）（TPPTS）2）的磷谱峰宽化，揭示有部份配合物解络、部分TPPTS被氧化成OTTPTS．本研究结果证实，适量水可促进催化剂中具氢甲酰化催化活性的铑膦物种形成，提高活性，但随反应进行，配合物将逐渐解络、膦配体逐渐被氧化，从而使催化剂逐渐失活．

关键词: 氢甲酰化, 负载型水溶性催化剂, 魔角旋转固体核磁, 1-已烯

Abstract:

The catalytic activity of hydroformylation of 1-hexene over SiO2-supported TPPTSRh(acac)(CO)2 (SAPC) was found to be evidently promoted when a proper amount of water-vapor was introduced into the reactant. Characterization results by using MAS NMR 31p spectra revealed that there were three types of phosphine species in the as-prepared SAPC: uncoordinated ligand TPPTS (over 70 mol%), surface complex {Rh(CO)(TPPTS)2} (chemical shift at δ=32.4, about 15 mol%), and unknown (about 10 mol%). By pre-treatment at 373 K for 2 under dry-snygas or at 333 K for 2 h under wet-syngas, the amount of phosphine species of the surface complex{Rh(CO)(TPPTS)2} was slightly increased to 20-30mol%, accompanying a few changes in ratios of the other phsophine species. When the SAPC was pre-treated at 373 K for 2 h under wet-syngas, however, the phosphine species at chemical shift of 32.4 was increased by over 40 mol% due to the in-situ formation of the surface complex {Rh(CO)(TPPTS)2}. It was found that the peak at δ=32.4 was also a principal one in the MAS NMR 31P spectra of the working SAPC, which demonstrated that the surface complex of {Rh(CO)(TPPTS)2 } would be a catalytic active species for olefin hydroformyaltion. After hydroformylation for 43 h, the deactivation of the catalyst occurred, corresponding to the observations of a broadness in peak ascribed to the surface complex of {An(CO)(TPPTS)z} in the MAS NMR 31P spectra, indicating that there existed de-coordination of the surface complex and oxidation of the ligand TPPTS during the reaction. The results suggest that a proper amount of water-vapor was able to accelerate the formation of active Rh-complex on the catalyst surface and thus increase the catalytic activity, whereas, it could be inevitably to cause the de-coordination of the surface complex and the oxidation of phosphine ligand under the reaction condition, hence leading to the deactivation of the catalyst.

Key words: Hydroformylation, Supported aqueous-phase catalyst, MAS NMR31P spectroscopy, 1-hexene