One-pot synthesis of nano-hierarchical SSZ-13 with superior catalytic performance in methanol-to-olefins reaction

CoNi Nanoparticles Supported on Hierarchical SAPO-34 Zeolite as a Catalyst for the Hydrolytic Dehydrogenation of Ammonia Borane

“…23,24 The acoustic cavitation phenomenon during ultrasonic irradiation was beneficial in suppressing the organization and agglomeration of zeolite particles, hence decreasing the crystal size. As reported in our previous work, 25 nanosized hierarchical SSZ-13 zeolite with CHA topology could be synthesized via ultrasonic pretreatment combined with a seed-assisted method. As proved by characterizations, ultrasonic pretreatment could significantly reduce the crystallization time and remarkably decrease the crystal to nanosize.…”

“…Very recently, ultrasonic pretreatment has been applied to the synthesis of hierarchical zeolite owing to its advantage in the formation of crystal nuclei and crystal growth, thereby accelerating particle growth rates and shortening the zeolite crystallization time. , The acoustic cavitation phenomenon during ultrasonic irradiation was beneficial in suppressing the organization and agglomeration of zeolite particles, hence decreasing the crystal size. As reported in our previous work, nanosized hierarchical SSZ-13 zeolite with CHA topology could be synthesized via ultrasonic pretreatment combined with a seed-assisted method. As proved by characterizations, ultrasonic pretreatment could significantly reduce the crystallization time and remarkably decrease the crystal to nanosize.…”

Assessing the effects of dealumination and bifunctionalization on 8-membered ring zeolite/zeo-type materials in the methanol-to-olefin catalytic process

“…[14][15][16][17][18][19][20] Beyond the conventional advantages associated with zeolite catalysts, such as a high specific surface area, uniform pore structure, inherent acidity, and remarkable hydrothermal stability, 8-MR zeolite/ zeo-type materials exhibit significantly enhanced selectivity for low-carbon olefins. [21][22][23][24][25][26][27][28] This heightened selectivity is attributed to their relatively small pore diameter, a characteristic known as "specific shape selectivity". [29][30][31] For the same reason, SAPO-34 or analogous 8-MR zeolite/zeo-type materials are prone to deactivation resulting from coke precursor accumulation, leading to a shorter lifetime.…”

“…[29][30][31] For the same reason, SAPO-34 or analogous 8-MR zeolite/zeo-type materials are prone to deactivation resulting from coke precursor accumulation, leading to a shorter lifetime. 21,24,[26][27][28][32][33][34][35][36][37][38][39][40][41][42] Although achieving higher selectivity for olefins is not a significant challenge in the MTO process over 8-MR zeolite/zeo-type materials, [21][22][23][24][25][26][27] enhancing the catalytic performance with an extended catalyst lifespan is crucial for strengthening overall process efficiency. Within the space of 8-MR zeolite/zeo-type materials utilized in the MTO process, extensive literature has investigated SSZ-39, 27,42 SAPO-18, [43][44][45][46][47] SSZ-13, 24,26,37,38,40 and SAPO-34 (ref.…”

“…In contrast, CHA topology consists of a threedimensional network of 8-MR channels with an ellipsoidal cage formed by stacking double six-membered rings and a three-dimensional intersecting channel structure. 21,[24][25][26][27][28][34][35][36][37][38][39][40][41][42]48,49 Regardless of their structural and topological distinctions, these materials share a common fate in the MTO processexhibiting high olefin selectivity but with a shorter catalyst lifespan. In zeolite catalysis, three common approaches are typically employed to modify the surface and physicochemical properties, potentially extending the catalyst's lifetime.…”