Regulation of intracrystalline diffusion plays a pivotal role in ensuring the catalytic stability of metal-supported zeolite catalysts. Herein, we successfully achieved precise modulation of intracrystalline diffusion in Au-loaded hierarchical TS-1 catalysts by two-step recrystallization approach. This modulation was achieved by manipulating the length of mesoporogens, characterized by the hierarchical factor (HF). The HF could be used as the descriptor to reveal the reaction stability and deactivation process including blocking degree (V: gold volume / V: volume not accessible for N) by the Au nanoparticles and coke formation in fresh and used catalysts, respectively. In addition, the enhanced selectivity was attributed to the improved hydrophobicity of Au/hierarchical TS-1 with gradually decreased terminal silanols by two-step recrystallization approach. This work not only provides the new strategy for the regulation of zeolite intracrystalline diffusion, but also could shed new lights on the industrial process of direct propene epoxidation with H and O.

中文翻译：

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Au/分级 TS-1 的晶内扩散调节可同时增强 H2 和 O2 丙烯环氧化反应的稳定性和选择性


晶内扩散的调控在确保金属负载沸石催化剂的催化稳定性方面起着关键作用。在此，我们通过两步重结晶方法成功实现了载金多级TS-1催化剂中晶内扩散的精确调节。这种调节是通过操纵中孔原的长度来实现的，其特征是分层因子（HF）。 HF 可用作描述符来揭示反应稳定性和失活过程，包括金纳米颗粒的阻塞程度（V：金体积/V：N 不可接近的体积）以及新鲜和用过的催化剂中焦炭的形成。此外，选择性的增强归因于通过两步重结晶方法逐渐减少末端硅烷醇的Au/多级结构TS-1的疏水性的改善。这项工作不仅为分子筛晶内扩散的调控提供了新的策略，而且为H和O直接丙烯环氧化的工业过程提供了新的思路。