期刊
MICROPOROUS AND MESOPOROUS MATERIALS
卷 148, 期 1, 页码 80-87出版社
ELSEVIER
DOI: 10.1016/j.micromeso.2011.07.021
关键词
Zeolite Beta; Boron exchange; Solid state NMR; Al insertion
类别
资金
- Ministry of Education and Training of Vietnam
Al insertion into boron Beta zeolite is quantitatively controlled by a three-step procedure. First, a mixed Na+/NH4+ counterion series balancing the charge of tetrahedral framework boron is prepared by ion exchange. Subsequent calcination converts NH4+ to H+ which is accompanied by the transformation of boron to trigonal coordination. Secondly, the calcined Na+/H+ samples are deboronated in water which allows a preferential extraction of boron at protonated sites. The sites which are balanced by sodium cations are protected against deboronation due to the low reactivity of tetrahedral boron. Finally, aluminum insertion into the vacated framework sites is achieved by ethanol solutions of Al(NO3)(3). The ratio of Na+/NH4+ counterions determines the extent of Al substitution for boron. Each step is quantitatively analyzed using solid state NMR. The extent of Al-B exchange can be tuned in a large range. (C) 2011 Elsevier Inc. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据