Seed-induced synthesis of mesoporous ZSM-5 aggregates using tetrapropylammonium hydroxide as single template

Insights to Achieve a Better Control of Silicon-Aluminum Ratio and ZSM-5 Zeolite Crystal Morphology through the Assistance of Biomass

“…The SAR based on the bulk composition was remarkably affected and values in the range of 25 to 150 were measured. Microporosities and mesoporosities are rather similar for all zeolites in line with literature data [22,23]. For the sake of clarity, a parent ZSM-5 was characterized by the nitrogen adsorption/desorption technique and similar microporous volumes were measured.…”

Controllable fabrication of single-crystalline, ultrafine and high-silica hierarchical ZSM-5 aggregates via solid-like state conversion

“…These nanocrystals size was obviously smaller than that of ZSM-5 aggregates reported in literature. 15 Comparatively, sample C-ZSM-5 is the one prepared without HTAB addition, which exhibits a mixture of zeolite crystals and amorphous phase ( Fig. S2A and B (ESI †)).…”

“…This may be attributed to the seeds to provide appropriate amount of surfaces to induce the nucleation, and then affect the growth and aggregation of crystal nucleus, leading to a sharp decrease in primary nanocrystals size of HA-ZSM-5. A further increase of the ratio of seed/ SiO 2 up to 0.04 and 0.06, the relatively higher seed/SiO 2 ratio may cause a high growth rate and the seeds had very little time to be dissolved and/or fragmented into small species and then produce secondary nuclei, 15 and therefore the primary nanocrystals of HA-313-4S-5H and HA-313-6S-5H became more larger than that of the aforementioned two samples (HA-313-0.5S-5H and HA-313-2S-5H) (inset of Fig. S5C and D, (ESI †)).…”

“…It has been reported that silicalite 1 (S-1) seeds have been used to fabricate HA-ZSM-5, however, the obtained HA-ZSM-5 sample remained still in micron range. 15 Meng and coworkers also reported the successful preparation of HA-ZSM-5 by a seed-induced method with S-1 crystals as the seeds, but only the samples with SiO 2 /Al 2 O 3 ratio of 50 were reported. 16 More importantly, Ryoo et al pioneered the use of a new kind of "two-in-one" template, combining features of both a primary template and a mesogenous template within one molecule, and successfully fabricated ZSM-5 nanosheets aggregates with intracrystal mesopores.…”

“…Beneting from the synergistic effect between HTAB and SSC method, seed/SiO 2 molar ratio is greatly reduced to 0.02, and interesting smaller nanocrystals size was achieved compared to what is achieved in literature. 15 This synthesis process was rapid and economical and shows potential for large-scale production. This catalyst design concept provides a new idea to fabricate high-silica HA-ZSM-5 or other zeolites that reveal fast mass transport, which will show a great potential for industrial applications in selective catalytic reactions involved bulky molecules.…”