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动态重组和TiIV活动位点的限制 控制二维型的烯氧化催化
Nicolás A Grosso-Giordano1, Adam S Hoffman2, Alexey Boubnov2
1Department of Chemical and Biomolecular Engineering , University of California, Berkeley , Berkeley , California 94720 , United States.
Journal of the American Chemical Society
|April 9, 2019
概括
将催化点封闭在酸盐口袋中,通过降低热障碍,显著提高了氧化率. 动态重组有利于这些封闭的场所,为表面反应控制提供新的途径.
科学领域:
- 不同质的催化
- 表面化学
- 材料科学
背景情况:
- 烯酸环氧化是一个重要的工业过程.
- 控制活动场所环境会影响催化性能.
- 酸材料具有可调节的催化性能.
研究的目的:
- 研究动态封闭对孤立的 (IV) 催化中心的影响.
- 阐明活性位点位置和重组对催化活动的作用.
- 探索浅表面口袋的潜力,以提高反应能力.
主要方法:
- 聚合 (IV) 集中在有控制限制的酸盐上 (无限制与12-MR口袋).
- 使用 tert-butyl氧化物对环烯环氧化的动力学研究.
- 用于电子结构分析的密度功能理论 (DFT) 计算.
- 激活参数的热力学分析 (和).
主要成果:
- 与非受限位相比,在12-MR口袋内的受限Ti (IV) 位点的环氧化率提高了约5倍.
- 动态重组导致限制活动场所的优先占用.
- 封闭降低了阻,促进了反应物的结合和过渡状态的形成.
- 激活度保持不变,而度变化解释了速率差异.
结论:
- 部分限制在浅表面的口袋增强催化反应通过效应.
- 动态重组在引导活跃站点到有利的封闭环境中起着关键作用.
- 这种方法为控制表面反应性提供了一种新的策略,特别是对于大型分子.
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