Engineering of zeolite BEA crystal size and morphology via seed-directed steam assisted conversion

Abstract

Seeds composition is crucial for the mechanism of seeding and therefore morphological, textural and catalytic properties of BEA zeolites.

Effect of the crystallization mechanism on zeolite BEA textural and acidic properties

“…These bulky products are most probably formed on the external surface and in the pre-surface layer of BEA particles or in the intercrystallite mesopores of BEA aggregates. 44 This observation is in line with the higher content of external acid sites determined by FTIR of adsorbed DTBMPy (Fig. 6b).…”

Adsorption Mechanism of Benzene Alkylation System Catalyzed by an Acid Catalyst: Effect of Pressure

“…Figure a,b are adsorption isothermals of single-component benzene (BEN) and propylene (PRO), as well as BEN and PRO in BEN: PRO = 1:1 mixture (BEN PRO and PRO BEN in BEN/PRO) in HY zeolite at 300 and 500 K, respectively. Figure c–f compares the adsorption isotherms in this study with ref , and reasonable agreement is found for both single and binary isothermals. Langmuir adsorption is followed for all adsorption isotherms in Figure .…”

“…Adsorption isotherm of BEN and PRO in HY zeolite from this work at (a) 300 and (b) 500 K. Comparison of this work and ref for (c) single-component BEN, (d) single-component PRO, (e) BEN in BEN/PRO (BEN PRO ), and (f) PRO in BEN/PRO (PRO BEN ). The one-component and binary mixtures are represented by solid and hollow symbols, respectively; the BEN and PRP of this work are represented by black and red symbols, respectively; and the data points at 373 and 423 K in the literature are represented by pink and blue symbols, respectively.…”

“…Therefore, zeolite-based processes are progressively substituting traditional AlCl −3 -based processes. 1,2 The two most common zeolites studied as alkylation catalysts are MWW (MCM-22) (9.7 and 5.0 Å) 3−6 and BEA (6.7 and 6.0 Å), 4,5,7 and promising results have also been found for FAU (12 and 7.4 Å), 8 MOR(6.7 and 6.5 Å), 9 and MFI (6.36 and 4.7 Å). 10 The two numbers in parentheses represent, in turn, the maximum diameter of the spheres that can be included (Sϕ Included ) and diffuse along (Sϕ Diffuse ) the corresponding zeolites.…”

“…Protonated zeolites have many advantages, such as a three-dimensional cage-like pore structure, high specific surface area, good hydrothermal stability, suitable acidity, environmental friendliness, and low cost. Therefore, zeolite-based processes are progressively substituting traditional AlCl –3 -based processes. , …”