Rapid Synthesis of Si-Rich SSZ-13 Zeolite under Fluoride-Free Conditions

Abstract

Rapid synthesis of Si-rich (SiO 2 /Al 2 O 3 > 100) SSZ-13 zeolite under fluoride-free conditions is highly desirable but still challenging. Herein, we for the first time report a rapid synthesis of all silica and aluminosilicate (SiO 2 /Al 2 O 3 > 100) SSZ-13 zeolite without the addition of fluoride species. The crystallization could be fully completed at 160 °C for 4 h when the aging of the starting gel is 3 h at room temperature after the addition of a zeolite seed. The key to success is the formation of more basic building units (4-and 6-membered rings) in the initial gel with the aging time of 3 h after the addition of a zeolite seed, leading to the successful rapid synthesis of Si-rich SSZ-13 zeolite. The obtained Si-rich SSZ-13 zeolite displays high crystallinity, uniform cubic morphology with a nanoparticle feature, and a large surface area. More importantly, the obtained Si-rich SSZ-13 zeolite displays excellent performance in the adsorption of ethanol and methanol-to-olefin reaction.

Fluoride- and Seed-Free Synthesis of Pure-Silica Zeolite Adsorbent and Matrix Using OSDA-Mismatch Approach

“…Thus, many efforts have been devoted to synthesizing pure-silica zeolites in the absence of fluorides. One of the synthetic strategies for overcoming this challenge is the utilization of pure-silica seeds combined with inorganic cations, − the pore filling ethanol, and other pure-silica zeolite as the main silica resource, , respectively. Unfortunately, such pure-silica seeds are inevitably synthesized in the fluoride medium or processed by dealumination postsynthesis.…”

Ultrafast Synthesis and Regulating Al Status of Mesoporous ZSM-48 Zeolite via a Pretreated-Seed-Solution-Assisted Strategy

“…Considerable efforts have been devoted to shortening the synthesis time during the past few decades . Recently, the seed-assisted method has offered a mature route to accomplish the synthesis of zeolites in a relatively short time, meanwhile enhancing the purity of product. , For example, seeds have played an indispensable role in the ultrafast synthesis route, which was developed by Okubo and Liu et al, fulfilling the preparation of a series of industrially important zeolites in hours, even minutes, − such as ZSM-5 and SSZ-13 .…”

Seed-Assisted Interzeolite Conversion Strategy for Fabricating Lewis Acid Sn-CHA Zeolites

“…In Xiao’s study for probing the mechanism of IZC from Si–Al FAU to CHA, CHA seeds were added to facilitate structural transformation . Moreover, in recent reports for advancing high Si-CHA zeolite preparation, they all took advantage of the seeding effect, such as providing the crystallization interface, reducing the particle size, shortening the induction period, and directing certain structures. , …”

“…23 Moreover, in recent reports for advancing high Si-CHA zeolite preparation, they all took advantage of the seeding effect, such as providing the crystallization interface, reducing the particle size, shortening the induction period, and directing certain structures. 24,25 Herein, a seed-assisted IZC strategy was designed to realize the fabrication of Sn-CHA from the commercially available USY. The addition of CHA seeds greatly promoted Sn-CHA growth and altered the crystallization pathway compared with the seed-free system.…”