FAU转晶合成MWW结构表征
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- 英文论文题名：Structure Characterization of FAU-MWW Transformation
- 论文作者：张羿 ; 邢恩会 ; 郑爱国 ; 向彦娟 ; 慕旭宏 ; 舒兴田 ; 徐广通
- 英文论文作者：Yi Zhang ; Enhui X ; Aiguo Z ; Yanjuan X ; Xuhong M ; Xingtian S ; Guangtong X ; Research Institute of Petroleum Processing ; Sinopec
- 年：2016
- 作者机构：中国石油化工股份有限公司石油化工科学研究院;
- 论文关键词：分子筛 ; 转晶 ; 透射电子显微镜 ; FAU ; MWW
- 会议召开时间：2016-07-01
- 会议录名称：中国化学会第30届学术年会摘要集-第三十二分会： 多孔功能材料
- 语种：中文
- 分类号：TQ424.25
- 学会代码：ZGHY
- 会议名称：中国化学会第30届学术年会-第三十二分会 ; 多孔功能材料
- 会议地点：中国辽宁大连
- 主办单位：中国化学会
- 学会名称：中国化学会
- 页数：1
- 文件大小：241k
- 原文格式：D
- 会议级别：全国
摘要
转晶是一种重要的分子筛合成方式,与传统水热合成相比可提高晶化速度、调变形貌和骨架元素分布、优化催化性能。然而对分子筛转晶机理、转晶对分子筛性质和催化性能的影响及调变等仍缺乏系统研究。本文以低硅铝比的FAU分子筛(SiO_2/Al_2O_3=5)为母体分子筛,在外加硅源、碱源、结构导向剂HMI的协同作用下,成功实现MWW结构分子筛(SiO_2/Al_2O_3>20)的合成并调控其晶粒尺寸及硅铝比~[1]。XRD结果(Fig.1a)显示NaY分子筛衍射峰逐渐消失,而MCM-49分子筛衍射峰逐渐生成,整个过程没有新的无定型相生成。在透射电子显微镜下对48小时转晶中间态两相界面处进行观察发现存在块状的NaY分子筛与薄片状的MCM-49分子筛(Fig.1b),其中片状MCM-49边缘呈锯齿状与传统水热合成的片状MCM-49分子筛(Fig.1c)具有不同的形貌。通过对转晶过程中相界面附近T原子排列及插入机制的表征研究发现转晶过程中部分双六圆环(d6r)有规律的得到保留,而这些保留的d6r促进了FAU结构分子筛向MWW结构分子筛的转变。
MWW structure zeolite was successful synthesized from FAU structure via the zeolite-zeolite transformation.XRD data proves that FAU structure was directly transformed into MWW structure.MWW structure zeolite was gradually generated at the consumption of FAU structure zeolite from exterior to interior of the crystals.A detailed TEM analysis is performed to study the FAU-MWW co-existing zeolites as intermediate states.The TEM data shows the bulk FAU crystals were delaminated into lamellar MWW zeolites by breaking SOD cages.d6 r in certain planes of FAU structure were retained to forming the MWW framework.
MWW structure zeolite was successful synthesized from FAU structure via the zeolite-zeolite transformation.XRD data proves that FAU structure was directly transformed into MWW structure.MWW structure zeolite was gradually generated at the consumption of FAU structure zeolite from exterior to interior of the crystals.A detailed TEM analysis is performed to study the FAU-MWW co-existing zeolites as intermediate states.The TEM data shows the bulk FAU crystals were delaminated into lamellar MWW zeolites by breaking SOD cages.d6 r in certain planes of FAU structure were retained to forming the MWW framework.
引文
[1]Shi,Y.;Xing,E.;Gao,X.;Liu,D.;Xie,W.;Zhang,F.;Mu,X.;Shu,X.;Micropor.Mesopor.Mater.2014,200:269.