高等学校化学学报

高等学校化学学报 ›› 1982, Vol. 3 ›› Issue (S1): 107.

• 研究论文 • 上一篇    下一篇

“原位”红外光谱追踪反应条件下催化体系的变化

潘伟雄, 刘金尧, 李升平, 夏云菊, 刘殿求   

  1. 清华大学化学化工系
  • 收稿日期:1982-02-05 出版日期:1982-12-31 发布日期:1982-12-31

“IN SITU” INFRARED TRACING BEHAVIOUR OF CATALYST SYSTEM UNDER REACTION CONDITIONS

Pan weixiong, Liu Jinyiao, Li Shengping, Xia Yunju, Liu Dianqiu   

  1. Dept. of Chem. & Chem. Eng., Tsinghua University, Beijing
  • Received:1982-02-05 Online:1982-12-31 Published:1982-12-31

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摘要：

为了观察和监测反应条件下中间产物和催化剂的变化,自行设计并安装了高温高压红外流动池。池体用不锈钢制成,窗口材料为NaCl或CaF2。它可承受100atm和200℃。整个测量系统包括高压釜、循环泵、红外池等。用Microlab-600型红外分光光度计记录图谱。池内温度和压力与反应釜桐同,可对反应液体、气体或气液混合物进行"原位"追踪。当用铑膦络合物催化剂进行丙烯氢甲酰化反应时,在近于工业反应条件下(t=10O℃,P=17atm,正丁醛溶剂),检测到催化剂母体Rh(acac)(CO)(PPh3)转化为活性物种RhH(CO)2(PPh3)2;在合成气压力较低时,只转化为RhH(CO)(PPh3)3;此活性物种随催化剂失活而消失。催化剂加氧失活后,检测到配位体三苯基膦氧化为氧化三苯基膦,催化剂生成二聚物,丙烯氧化成丙酮,追踪到原料气CO氧化为CO3的动态过程。本文对"原位"红外光谱实验方法、高温高压红外池作了介绍,并给出有关实验数据和结果。

Abstract:

In order to observe and identify the intermediates and the change of the catalyst under reaction conditions, we have designed and assembled a high temperature and high pressure infrared spectrophotometer cell. The cell, constructed from stainless steel with NaCl or CaF3 windows, can withstanb 100 atm, and 200℃ The measurement system consists of autoclave, circulating pump and spectrophotometer cell. The infrared spectra are recorded using a Microlab-600 infrared spectrophotometer. The temperature and pressure in the cell are the same as that in the autoclave, so that it can be used in "in situ" tracing the behaviour of liquid, gase and liguid-gas mixtures.For the hydroformylation reaction of proplene with rhodium-phosphine complex catalyst, the transition of catalyst precursor Rh(acac)(CO)(PPh3) to active species RhH(CO)2(PPh3)3 has been recorded under the industrial reaction conditions (t=100℃, p=17atm. butyl aldehyde as solvent). If the pressure of synthetic gas is rather low, only RhH(CO)(PPh3)3 can be identified. The active species RhH(CO)2(PPh3)2 disappears while the catalyst loses its reactivity. The oxidation of the ligand PPh3 and the formation of OPPh3 have been characterized under the oxygen atmosphere. In this case, the deactivation of catalysts, the formation of catalyst dimer, oxidation of proplene to acetone and the dynamics of CO oxidation to form CO3 have been traced.In this paper, the experimental method concerning the "in situ" infrared tracing technique, high temperature and high pressure I. R spectrophotometer cell have been described and some experimental data and results have been given.

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