Facile synthesis of nanosized mordenite and beta zeolites with improved catalytic performance: non-surfactant diquaternary ammonium compounds as structure-directing agents

Abstract

Non-surfactant diquaternary ammonium compounds have already been used for obtaining various zeolites in nanocrystalline form. However, facile synthesis of nanocrystals of mordenite (MOR) and Beta (BEA) in this way remains...

Nanocrystalline BEA-CNT Composites with High Metal Dispersion Obtained via Inter-Zeolite Transformation for Antibacterial Application

“…The XRD patterns were collected by a Bruker D8 ADVANCE instrument with 0.02° step sizes in the 2θ range of 5–60°. The relative crystallinity (%) of the BEA zeolite was calculated based on the summation of representative peak areas of two diffraction peaks at 2θ of 7.7 and 22.2°, , in which the sample with the highest crystallinity or the completely crystallized sample was used as a reference (100% relative crystallinity). The related equation is shown as follows relative 0.25em crystallinity 0.25em ( % ) = XRD 0.25em peak 0.25em area 0.25em of 0.25em desired 0.25em sample XRD 0.25em peak 0.25em area 0.25em of 0.25em reference × 100 The morphology of the obtained samples was observed by a scanning electron microscope (SEM).…”

“…The XRD patterns were collected by a Bruker D8 ADVANCE instrument with 0.02° step sizes in the 2θ range of 5–60°. The relative crystallinity (%) of the BEA zeolite was calculated based on the summation of representative peak areas of two diffraction peaks at 2θ of 7.7 and 22.2°, , in which the sample with the highest crystallinity or the completely crystallized sample was used as a reference (100% relative crystallinity). The related equation is shown as follows The morphology of the obtained samples was observed by a scanning electron microscope (SEM).…”

Modification of Zeolite Morphology via NH4F Etching for Catalytic Bioalcohol Conversion

“…[b] Relative crystallinity (%) was calculated based on the summation of the representative peak area of two diffraction peaks at 2θ = 7.7°and 22.2°, using untreated BEA as a standard (i. e., relative crystallinity of 100 %). [30] the transportation of fluoride species into the framework aluminosilicate sites with faster rate than the smaller pore zeolites. This explanation is in agreement with the NH 4 F etching rates on various zeolite framework shown in Figure S4.…”

Nanoplatelet Mordenite Zeolite with a Controlled Aspect Ratio: Implications for the Alkylation of Benzene with Benzyl Alcohol

“…Mordenite (MOR), as one of the “big five” zeolites, is extensively used in various important catalytic reactions, such as alkylation, isomerization, and carbonylation. − As shown in Figure S1, the framework channel system of MOR zeolite comprises 12-MR (main channels, 0.65 nm × 0.70 nm) and 8-MR (oval channel, 0.26 nm × 0.57 nm) parallel to the c -axis, interconnected by 8-MR (side packet, 0.34 nm × 0.48 nm) along the b -axis. The catalytic performance of MOR zeolite is not only determined by the acid properties but also importantly determined by the morphology-dependent diffusion properties.…”