Dynamic In Situ NMR of Catalysis

南加州大学的James Haw教授的项目得到了分析和表面化学计划的支持，旨在实现对沸石和固体酸催化剂上发生的催化反应的基本了解。设计了一种特殊的脉冲猝灭催化反应器，可以用核磁共振波谱研究催化反应。用这个装置可以跟踪化学中间体的变化，时间分辨率为0.2S；反应可以通过快速冷却或引入阻滞剂来熄灭。理论计算也被用来通过计算的核磁共振化学位移和四极耦合常数来模拟实验结果。本项目要研究的两个催化体系的具体例子包括合成吡啶和丁烯异构化，这两个过程都是由沸石催化的过程。利用核磁共振波谱技术研究了在沸石和固体酸上简单吸附气体催化转化为复杂分子的过程。南加州大学的James Haw教授开发了一种将化学反应体系与猝灭相结合的方法，使复杂的催化体系得以研究。新的分析方法将用于研究合成吡啶和合成橡胶前驱体丁烯的异构化等具有重要工业意义的项目。

The project of Professor James Haw of the University of Southern California, supported by the Analytical and Surface Chemistry Program, seeks to achieve a fundamental understanding of the catalytic reactions that occur on zeolites and solid acid catalysts. A special pulse quench catalytic reactor has been designed that allows the investigation of catalytic reactions by nuclear magnetic resonance spectrometry. Changes in chemical intermediates can be followed with this device with a time resolution of 0.2 s; reactions are quenched by rapid cooling or by the introduction of inhibiting reagents. Theoretical calculations are also used to model the experimental NMR results via calculated NMR chemical shifts and quadrupolar coupling constants. Two specific examples of catalytic systems to be studied in this project include the synthesis of pyridine and butene isomerization, both are processes which are catalyzed by zeolites. Nuclear magnetic resonance spectrometry is used to study the catalytic transformation of simple adsorbed gases into more complex molecules on zeolites and solid acids. Professor James Haw at the University of Southern California has developed a combination of chemical reaction system with quenching that allows complex catalytic systems to be studied. The new analytical method will be used to study the industrially important projects of pyridine synthesis and the isomerization of butene, a precursor to synthetic rubber.