Fast, low-pressure, low-temperature microwave synthesis of ABW cesium aluminosilicate zeolite nanocatalyst in organotemplate-free hydrogel system
Document Type
Article
Publication Date
2-1-2020
Abstract
Cs-ABW zeolite nanocrystals were synthesized using a microwave-assisted hydrothermal technique without an organic template. Using powder X-ray diffraction Rietveld refinement and spectroscopy, we found that pure ABW-type CsAlSiO4 zeolite nanocrystals (Si/Al ratio = 1.08) with an orthorhombic structure (space group Pc21n, a = 9.4425(21) angstrom; b = 5A437(11) angstrom; c = 8.9152(19) angstrom) can be crystallized from a clear precursor solution of 4SiO(2):1Al(2)O(3):16Cs(2)O:160H(2)O (180 degrees C, 6 min). The Cs-ABW nanoparticles had a mean particle size of 68 nm and were thermally and colloidally stable. The nanocrystals-which had high accessible basic sites, (Si-O-Al)Cs--(+), located at their external surface-were active in catalyzing the cyanoethylation of aliphatic alcohols under non-microwave instant heating, with 100 % selectivity to the desired product and high catalyst reusability. Furthermore, the cyanoethylation of methanol catalyzed by nanocrystalline Cs-ABW under instant heating had equal or better reactivity than those catalyzed by other solid base catalysts.
Keywords
Sol-gel chemistry, Microporous materials, Crystal growth, Crystal structure, Catalytic properties
Divisions
nanocat
Funders
None
Publication Title
Materials Research Bulletin
Volume
122
Publisher
Elsevier
Publisher Location
THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND