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<p>We have investigated the effect of different impurities (CO, CO<sub>2</sub>, CS<sub>2</sub>, CH<sub>3</sub>OH, H<sub>2</sub>O, C<sub>4</sub>H<sub>4</sub>S) on the silicon-bridged diphosphine(PNSiP)/CrCl<sub>3</sub>(C<sub>4</sub>H<sub>8</sub>O)<sub>3</sub>/modified methylaluminoxane ethylene tri-/tetramerization system. The results showed that the addition of trace impurities has a certain inhibitory effect on catalytic activity. The influence of impurities on the catalytic activity of the catalyst system was as follows: CO &gt; CO<sub>2</sub> &gt; CS<sub>2</sub> &gt; CH<sub>3</sub>OH &gt; H<sub>2</sub>O &gt; C<sub>4</sub>H<sub>4</sub>S. CO showed the most significant inhibitory effect in reducing activity from 1.75 × 10<sup>6</sup>&#xa0;g/(mol Cr h) to 0.74 × 10<sup>6</sup>&#xa0;g/(mol Cr h) at an addition of 0.2&#xa0;ppm. Through the analysis of nuclear magnetic resonance (NMR) and ultraviolet–visible spectrophotometry (UV–vis), we found that carbon monoxide mainly inactivates the catalytic system by coordinating with chromium active sites, while methanol and water reduce the catalytic activity by destroying the structure of modified methylaluminoxane. Furthermore, we also proposed a possible reaction path between carbon monoxide and the chromium active center.</p> Graphical abstract <p></p>

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Effect of traces of impurities on the silicon-bridged diphosphine/CrCl3(C4H8O)3/modified methylaluminoxane ethylene tri-/tetramerization system

  • 期刊论文

  • 发表日期：

    2025年10月11日

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  • Lirong Guo,
  • Xiaodie Yang,
  • Huijuan Shao,
  • Xuzhi Zhang,
  • Yating Wang,
  • Tao Jiang

摘要

We have investigated the effect of different impurities (CO, CO2, CS2, CH3OH, H2O, C4H4S) on the silicon-bridged diphosphine(PNSiP)/CrCl3(C4H8O)3/modified methylaluminoxane ethylene tri-/tetramerization system. The results showed that the addition of trace impurities has a certain inhibitory effect on catalytic activity. The influence of impurities on the catalytic activity of the catalyst system was as follows: CO > CO2 > CS2 > CH3OH > H2O > C4H4S. CO showed the most significant inhibitory effect in reducing activity from 1.75 × 106 g/(mol Cr h) to 0.74 × 106 g/(mol Cr h) at an addition of 0.2 ppm. Through the analysis of nuclear magnetic resonance (NMR) and ultraviolet–visible spectrophotometry (UV–vis), we found that carbon monoxide mainly inactivates the catalytic system by coordinating with chromium active sites, while methanol and water reduce the catalytic activity by destroying the structure of modified methylaluminoxane. Furthermore, we also proposed a possible reaction path between carbon monoxide and the chromium active center.

Graphical abstract