Incorporation of boron into nano-size MFI zeolite structure using a novel microwave-assisted two-stage varying temperatures hydrothermal synthesis

Pervaporation separation of ethanol–water mixtures through B-ZSM-11 zeolite membranes on macroporous supports

“…Such contraction of unit cell evidenced the successful incorporation of boron atom into MEL framework[3,20,34]. 2c), suggesting the contraction of the unit cell in the B-ZSM-11 accordingto Bragg equation (this will be discussed later).…”

“…2θ position compared to those of silicalite-2 crystals (Fig. However, the exact mechanism of this change in crystal morphology after the introduction of boron was still not so clear.--------Fig.3--------FTIR analysis has been commonly used to determine the isomorphic incorporation of boron atom into zeolite structure[25,34].Fig. Such contraction of unit cell evidenced the successful incorporation of boron atom into MEL framework[3,20,34].…”

Ethanol perm‐selective B‐ZSM‐5 zeolite membranes from dilute solutions

“…Then, the resulting solution was sealed into a Teflon-lined autoclave, which was placed in the oven preheated to a certain temperature for 48 h. The seeds with different sizes (BZ1 and BZ2) were obtained at 448 K and 423 K, respectively. The zeolite seed with size of 0.4 lm (BZ3) was also prepared from a clear solution of 1 TEOS/0.2 TPAOH/0.02 H 3 BO 3 /30 H 2 O at 423 K for 48 h. The seed with size of 0.1 lm (BZ4) was synthesized by a two-step MWassisted hydrothermal synthesis according to the method reported by Mehdipourghazi et al 28 For comparative purposes, silicalite-1 zeolite seeds with sizes of 1 and 0.1 lm (S1 and S2) were also prepared according to our previous work 29 and the procedure described by Motuzas et al, 30 respectively. The details of the molar compositions and synthesis conditions of B-ZSM-5 and silicalite-1 seeds were summarized in Table S1 in the Supporting Information.…”

“…It is well-known that FT-IR analysis is commonly used to characterize MFI zeolite structure and to determine isomorphous substitution of boron atoms in the zeolite framework. 21,28 Figure S4 in the Supporting Information depicts the FT-IR spectra of as-synthesized B-ZSM-5 seeds (BZ2-4) and silicalite-1 seeds (S1). According to references, 21,22 typical absorbance bands near 1228, 1100, 800, 550, and 450 cm 21 from MFI structure are detectable in all spectra.…”

Synthesis of zeolite NA‐A using single mode microwave irradiation at atmospheric pressure: The effect of microwave power

“…The activation energy is also observed to decrease during MW irradiation; this decrease in the activation energy compared to conventional heating might be due to higher atomic mobility in the crystal lattice. [2] Microwave-assisted synthesis of zeolites and nanozeolites has been reported in many previous works [3][4][5][6][7][8] and has been found to assist in shortening crystallization time, accelerating nucleation, producing narrower size distributions, reducing undesirable phases, and obtaining different morphologies. [9][10][11] Furthermore, the employment of the microwave technique in the synthesis of nanoporous materials has been shown to produce multiple effects, for instance: short heating times, inductive heating, specific energy dissipation via microwave energization of the hydroxylated surface or associated water molecules in the boundary layer, and formation of high potential active water molecules.…”