Zeolites are crystalline microporous materials widely used in industrial applications, and their catalytic and adsorption performances are profoundly influenced by intrinsic defects. However, characterizing the multiscale distribution of such defects remains a major challenge, especially in zeolites with complex stacking faults such as Beta zeolite. Herein, we develop a strategy that integrates high-resolution transmission electron microscope (HRTEM) imaging with controlled stepwise etching to probe the defects distribution in Beta zeolite across multiple length scales. Experimental results suggest that the defective domains in individual Beta zeolite crystals are heterogeneously distributed and preferentially aligned along the c axis. HRTEM imaging further reveals a preferential localization of defects at specific T sites within zeolite framework. Moreover, the etching process simultaneously generates a hierarchical Beta zeolite, whose titanosilicate analogue exhibits superior catalytic performance in cyclohexene epoxidation reaction. This work provides new insights into recognizing the multiscale defects distribution in zeolites, which establishes a direct link between the defect engineering and enhanced catalytic performance.

Generating hollow structure inside titanium silicalite-1 (TS-1) is a widely used method to improve its liquid-phase oxidation catalytic performance in industry. However, traditional dissolution-recrystallization method usually required a large amount of aqueous solution of organic template, leading to unfavorable polluted waste, low production efficiency, and high manufacture cost. Here, a facile and environmental friendly strategy was proposed for the post-synthesis of hollow TS-1 zeolite with a solvent-free method utilizing NH₄HCO₃ and tetrapropylammounium bromide as selective etching agents, which reduced the usage of organic template and avoided the liquid waste. The high crystallinity, the microporous structure, and the active Ti sites were preserved at a high product yield (> 93%). The formation mechanism of hollow structure was also investigated by exploring effects of different reactants and experimental parameters. Meanwhile, the obtained hollow TS-1 showed an outstanding performance in the epoxidation of 1-hexene in comparison to the parent zeolite.