Syntheses, structure solutions, and catalytic performance of two novel layered silicates
Journal
Dalton Transactions
Journal Volume
44
Journal Issue
35
Pages
15567-15575
Date Issued
2015
Author(s)
Liang, Jie
Su, Jie
Chen, Yanping
Li, Zhaofei
Li, Kuo
Zhang, Hao
Zou, Xiaodong
Liao, Fuhui
Wang, Yingxia
Lin, Jianhua
Abstract
Two novel layered silicates, PKU-13 and PKU-13a, were hydrothermally synthesized by using trimethylpropylammonium hydroxide as the structure directing agent (SDA). Their structures were solved by using powder X-ray diffraction data in combination with electron diffraction technique and NMR spectroscopy. These two silicates are built from the same r52 layer in different stacking modes: the adjacent r52 layers in PKU-13a have a 0.5b + 0.68c shift compared with those in PKU-13. The difference is due to the SDA cations located between the layers. The SDA cations exist as a monolayer in the structure of PKU-13, and link the adjacent layers by Coulomb actions in combination with strong hydrogen bonds. In PKU-13a, the SDA cations present in the bi-layer expend the distance between layers and destroy the inter-layer hydrogen bonds. PKU-13a can transform to PKU-13 after treatment with acetic acid solution. The co-existence of intra-layer hydrogen bonds in PKU-13 interfere in its condensation to an ordered crystalline microporous framework. Both PKU-13 and PKU-13a exhibit good catalytic activities as base catalysts in the Knoevenagel condensation reaction.
SDGs
Type
journal article