Busting the efficiency of SAPO-34 catalysts for the methanol-to-olefin conversion by post-synthesis methods

Abstract

As an effective non-petroleum based process for producing light olefins, the methanol-to-olefin (MTO) route has become an indispensable alternative to the industrial production of light olefins. The silicoaluminophosphate SAPO-34 zeolite (CHA-type structure) has proven to be an efficient industrial catalyst for the production of ethylene and propylene by the MTO reaction. However, the inherent structure and related diffusion limitations of SAPO-34 limit the mass transport and thus cause rapid deactivation of the catalyst. Fabrication of hierarchical SAPO-34 zeolite is one of the most effective strategies to address the intrinsic diffusion limitation. As simple, inexpensive, and efficient approach, the post-synthetic route has attracted considerable attention and widely used to introduce secondary meso-/macropores into the microporous SAPO-34 material. Significant effort has been dedicated to the development of post-synthesis strategies to prepare hierarchical 2 SAPO-34 zeolite, thereby enhancing its catalytic performance in the MTO process. This mini-review addresses the post-synthesis preparation of hierarchical SAPO-34 catalysts and their MTO performance. Furthermore, some current problems and prospects of the post-synthesis route to hierarchical SAPO-34 catalysts are also revised. We expect this mini-review to inspire the more efficient preparation of hierarchical SAPO-34 catalysts for the MTO process.

A Review on SAPO‐34 Zeolite Materials for CO2 Capture and Conversion

“…[55,74] SAPO-34 has been applied in catalytic processes, such as MTO. [75][76][77][78][79][80][81][82][83][84][85] Related research works [86,87] have shown that synthesizing a hierarchical structure that reduces the crystal size of the material regulates the crystal acidity, which can improve the catalytic activity of SAPO-34, especially for MTO reactions.…”

“…Post-synthetic strategies in SAPO-34 zeolite to design hierarchical structural zeolites for enhanced olefin production while overcoming deactivation problems were highlighted by Yang et al. [79] In addition, state-of-the-art molecular sieve membranes made of SAPO-34 were discussed. [89,90] Singh et al [91] discussed porous materials for CO 2 capture, whereas Kumar et al [15] reviewed CO 2 capture by various zeolites in general.…”

“…SAPO‐34 materials have received considerable scientific attention because of their high activity toward light olefins [55,74] . SAPO‐34 has been applied in catalytic processes, such as MTO [75–85] . Related research works [86,87] have shown that synthesizing a hierarchical structure that reduces the crystal size of the material regulates the crystal acidity, which can improve the catalytic activity of SAPO‐34, especially for MTO reactions.…”

Recent Progress of SAPO-34 Zeolite Membranes for CO2 Separation: A Review

“…In addition to distinct pore size and volume, SAPO-34 material exhibits moderate to high hydrophobicity and has high thermal and hydrothermal stability. Due to these characteristic features, SAPO-34 has been extensively used in the methanol to olefin (MTO) process [ 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 ]. In recent years, SAPO-34 has been investigated for CO 2 remediation, including CO 2 capture [ 49 , 50 , 51 ], conversion [ 52 , 53 , 54 ], and separation [ 49 ].…”

Advanced scanning electron microscopy techniques for structural characterization of zeolites

“…7,8 Many approaches have been designed to fabricate hierarchical structures in zeolites by introducing secondary meso-/ macro-pores into the microporous framework, providing better access to micropores. 9,10 In the fabrication process, how to pre-cisely characterize the inner architecture of zeolite plays an important role in understanding the hierarchical porous system that determines their properties and potential applications. N 2 adsorption is a classical method applied for measuring the pore size distribution across the entire range of bulk zeolites.…”