High accessibility to active sites of hierarchical nanocrystalline Zr-β zeolite in ethanol–acetaldehyde conversion to 1,3-butadiene

Abstract

Hierarchiral β zeolites with abundant intercrystalline mesopores for improved accessibility to active sites via Silanization-based Crystallization.

Perspectives on Recent Advances in Hierarchical Zeolites for Bioethanol Conversion to Chemicals, Jet Fuels, and Carbon Nanotubes

“…Reaction conditions: 320 °C; WHSV = 1.04 h –1 . Reproduced with permission from ref . Copyright 2023 Royal Society of Chemistry.…”

“…Besides the introduction of open Zr sites, the hierarchical zeolite also provides a mesoporous feature, which influences butadiene selectivity. Jiang and co-workers 122 have successfully prepared the hierarchical Zr/BEA zeolite with the different microporosity/mesoporosity ratio by dealumination-metallization strategy for the Ostromislensky process. The designer hierarchical zeolite has been employed to improve the diffusion of zeolite catalysts, improving desired product selectivity.…”

“…However, if the catalyst contains excessive mesoporosity, a relatively high selectivity of crotonaldehyde and heavy compounds is obtained. 122 Although postsynthetic treatment approaches enhance ethanol conversion into butadiene, they come with certain drawbacks, such as the severe treatment conditions that affect the zeolite crystals. For example, Klein and co-workers 123 successfully prepared the hierarchical beta and LTA zeolite catalysts via dealumination for the Ostromislensky process.…”

“…This finding indicated that the hierarchical structure could improve the accessibility of active sites and diffusion inside micropores, which are the key parameters for promoting crotonaldehyde reduction and butadiene production. However, if the catalyst contains excessive mesoporosity, a relatively high selectivity of crotonaldehyde and heavy compounds is obtained …”