Hierarchical Shell‐Like ZSM‐5 with Tunable Porosity Synthesized by using a Dissolution–Recrystallization Approach

Abstract

Zeolites have been widely used in various fields in industry, such as catalysis, separation, and adsorption, etc. The small pore size of the micropores in the zeolite could lead to severe diffusion resistance in mass transfer. Numerous efforts have been dedicated to imposing hierarchical pore systems into zeolites by using templates or leaching methods. Here, we report the synthesis of single-crystalline hierarchical shell-like ZSM-5 by utilizing a dissolution-recrystallization post-treatment on mesoporous ZSM-5. Tetrapropylammonium hydroxide solution was used in the post-treatment. The hierarchical porosity in the crystalline shell can be controlled by adding sodium cations into the synthesis system. The hierarchical shell-like ZSM-5 reported here shows higher catalytic activity in acetalization reactions containing bulky molecules.

Controlled Nanostructure of Zeolite Crystal Encapsulating FeMnK Catalysts Targeting Light Olefins from Syngas

“…45 For FeMnK@Hol-S-1, type-IV isotherms with H2 hysteresis loop were observed, which consist of an abrupt step at approximately P/P 0 = 0.45, characteristic of the cavitation phenomenon or pore blocking effect. 46,47 This feature implies that the sample has an ink-bottle pore system, which means that the crystal cavity communicates with outside only through the narrow neck (generally less than 4 nm). 47 Similarly, FeMnK@HM-S-1 also presents type-IV isotherms, but with a reduced H2 hysteresis loop, suggesting that the shell consists of macropores or mesopores (wider than 4 nm), which makes the gas easily penetrate into the cavity, in agreement with the TEM and SEM results.…”

State of the Art and Perspectives of Hierarchical Zeolites: Practical Overview of Synthesis Methods and Use in Catalysis

“…Acetylation catalysis of cyclohexanone with these materials showed promising enhancement of the catalytic activity. [92] Recently, the dissolution-recrystallization was also applied in the presence of a binder. Zhou et al created a full-zeolitic hierarchical monolytic ZSM-5.…”

“…Acetylation catalysis of cyclohexanone with these materials showed promising enhancement of the catalytic activity. [ 92 ]…”

Effective Regulation of the Au Spatial Position in a Hierarchically Structured Au/HTS-1 Catalyst: To Boost the Catalytic Performance of Propene Epoxidation with H2 and O2

“…The reduced crystal size and abundant 45 nm mesoporous structure may result from "dissolution−recrystallization" of the TS-1 seed from the inside out. 47 Besides the pore structure, hydrophobicity is another important physical and chemical property of Ti-containing supports. The Supporting Information (Figure S1) shows the 29 Si MAS NMR spectra of conventional TS-1 and HTS-1 supports.…”