Recently, a research team led by Researcher Gao Zhe from the Institute of Coal Chemistry (ICC) of the Chinese Academy of Sciences (CAS), based on their previous understanding of atomic layer deposition (ALD) technology, constructed an ALd-Sn-Beta catalyst with precise localization of Sn species on the surface of Beta zeolites using ALD technology. This research provides an important theoretical and experimental basis for the development of efficient Lewis acid catalysts. The result was published in Science China Chemistry recently, with the title of "Tuning Sn location in zeolites by atomic layer deposition to construct efficient Lewis acid catalysts for Baeyer-Villiger oxidation reaction".

ABSTRACT: Lewis acid catalysts are a versatile class of catalysts in acid-catalyzed reactions. As important solid Lewis acid catalysts, Sn-Beta zeolites have attracted much attention due to their excellent catalytic performances in various reactions. However, it is difficult to precisely control the location of Sn sites in the zeolites by traditional methods. Here we used atomic layer deposition (ALD) to introduce Sn species into dealuminized Beta zeolites to tune the Sn location in the zeolites, obtaining ALD-Sn-Beta. For comparison, the Im-Sn-Beta catalyst was also prepared by impregnation methods. The Sn species of ALD-Sn-Beta are precisely introduced into the silanol nests of the dealuminated Beta zeolite, forming the framework Sn species and increasing the number of Lewis acid sites. Meanwhile, the Sn species are mainly located on the surface of the catalysts. For Im-Sn-Beta, the Sn species are located on the surface and in the channels of zeolites, forming larger SnOx particles. Thanks to the precisely tuned Sn location, active Lewis acid sites of ALD-Sn-Beta are more than that of Im-Sn-Beta and are located on the surface, resulting in the enhanced cyclohexanone conversion and caprolactone selectivity in the Baeyer-Villiger (B-V) oxidation of cyclohexanone than Im-Sn-Beta. This study provides valuable insights into the design and synthesis of highly efficient Lewis acid catalysts, which are crucial in many reactions.

Zhao, K., Zhang, S., Wu, Z. et al. Tuning Sn location in zeolites by atomic layer deposition to construct efficient Lewis acid catalysts for the Baeyer-Villiger oxidation reaction. Sci. China Chem. 68, 5235–5243 (2025). https://doi.org/10.1007/s11426-025-2685-2