Fast, low-pressure, low-temperature microwave synthesis of ABW cesium aluminosilicate zeolite nanocatalyst in organotemplate-free hydrogel system
[Display omitted] •Microwave synthesis of organotemplate-free nanoscale Cs-ABW is reported.•The nanocrystals are formed from 6 min onwards at 180 °C and ∼20 bar.•The nanocrystals (∼68 nm, Si/Al = 1.08) have orthorhombic structure (space group Pc21n).•The nanocrystals are active in cyanoethylation of...
Saved in:
Published in | Materials research bulletin Vol. 122; p. 110691 |
---|---|
Main Authors | , , , , , , |
Format | Journal Article |
Language | English |
Published |
Elsevier Ltd
01.02.2020
|
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | [Display omitted]
•Microwave synthesis of organotemplate-free nanoscale Cs-ABW is reported.•The nanocrystals are formed from 6 min onwards at 180 °C and ∼20 bar.•The nanocrystals (∼68 nm, Si/Al = 1.08) have orthorhombic structure (space group Pc21n).•The nanocrystals are active in cyanoethylation of aliphatic alcohols and is recyclable.•Nanosized Cs-ABW had equal or better reactivity than other reported solid base catalysts.
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) Å; b = 5.4437(11) Å; c = 8.9152(19) Å) can be crystallized from a clear precursor solution of 4SiO2:1Al2O3:16Cs2O:160H2O (180 °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. |
---|---|
ISSN: | 0025-5408 1873-4227 |
DOI: | 10.1016/j.materresbull.2019.110691 |