Hierarchical Zeolites‐confined Metal Catalysts and Their Enhanced Catalytic Performances

Abstract

The confinement of metal species within hierarchical zeolites combines the acidic/basic sites of zeolites, the enhanced mass transfer of mesoporous system, and the inside active metal sites, leading to high activity, unique selectivity, and superior stability in chemicals synthesis, energy and environment catalysis. To date, review on this emerging topic is rarely reported. Herein, we classify five metals-hierarchical zeolites composite (metal@hierarchical zeolites) according to the location of metals on hierarchical structure, including metals located on micropores, intercrys-talline mesopores, intracrystalline mesopores, hollow nanobox and mesoporous shells. The synthesis and catalysis applications of metal@hierarchical zeolites composite are provided, highlighting the rational design of catalyst preparation, the improved catalytic efficiency and stability of metal species. Finally, we discuss the current limitations and future opportunities for this emerging field. This Review is expected to inspire more developments and applications of metal@hierarchical zeolites.

A route to selectively increase the microporous structure of zeolite and its optimization in the ethanol to butadiene reaction

“…A larger micropore volume could decrease diffusion limitation and diffusion path length, which is beneficial for the catalytic performance of catalysts that are a long time on stream. 41,42 Micropores could offer a better confinement effect for the formation of butadiene, while mesopores may produce carbon species with a larger space volume than butadiene; 2,43 hence, it is reasonable that a high ratio of micropore volume to mesopore volume could improve the performance of catalysts in the ETB reaction. The catalytic performance of the regenerated catalyst was studied.…”

Application of Mesoporous/Hierarchical Zeolites as Catalysts for the Conversion of Nitrogen Pollutants: A Review

“…The high potential of mesoporous zeolites is confirmed by numerous current review articles devoted to their synthesis, e.g., [1][2][3][4][5][6][7], their application in catalysis and adsorption in general [8,22,23], or in particular processes such as biomass conversion [24] or hydrocarbon oxidation reactions [25]. Despite the large amount of general scientific literature describing mesoporous zeolites, only a few reports focus on individual environmental catalysis reactions, bringing together the state of the art.…”