摘要
以乙二胺为结构导向剂,在200℃加热物质的量组成为nAl2O3∶nP2O5∶nen∶nH2O=1∶1∶2∶226的初始混合物(en=乙二胺),合成了三维开放骨架磷酸铝化合物Al PO4-12。用X-射线衍射、元素分析、p H测量、液体核磁共振以及电喷雾质谱研究了其晶化过程。依据质谱数据,开发了一个系统枚举在晶化过程中可能生成的小结构单元分子式的方法。研究发现在Al PO4-12的晶化过程中经历了层状磷酸铝Ui O-15和Ui O-13中间相,液相中Al物种的浓度极低,在晶化过程中生成的小结构单元中P-OH逐渐增多,乙二胺分子逐渐质子化,在晶化过程中生成了磷酸铝的4元环和6元环。用电喷雾质谱研究晶化过程中的液相可以获得小结构单元的结构和组成信息。
Upon heating the initial mixture with the composition of nAl2O3∶nP2O5∶nen∶nH2O=1∶1∶2∶226 at 200 ℃ for 12 h, where en is ethylenediamine, a three-dimensional open-framework aluminophosphate A1PO4-12 was obtained. The crystallization process of AlPO4-12 was investigated using X-ray diffraction, elemental analysis, pH measurement, liquid NMR, and electrospray ionization mass spectra （ESI-MS）. On the basis of the ESI-MS data, a method was developed to systematically enumerate the formula of the fragments formed during the crystallization of AlPO4-12. It was found that intermediate phases of layered aluminophosphates UiO-15 and UiO-13 were formed prior the crystallization of ALP04-12. The concentration of A1 species in the liquid throughout the crystallization was extremely low. A gradual increase of P-OH group in the P species in the liquid and a gradual protonation of ethylenediamine during the crystallization were observed. The formation of 4- and 6-membered rings was confirmed by the ESI-MS data. The utilization of ESI-MS in the investigation of the crystallization process of microporous crystalline materials may allow us to determine the structural information and the formula of the fragments formed during the crystallization.
出处
《无机化学学报》
SCIE
CAS
CSCD
北大核心
2015年第9期1885-1893,共9页
Chinese Journal of Inorganic Chemistry
基金
国家自然科学基金(No.21171063
国家优秀青年科学基金(No.21222103)
国家重点基础研究发展规划项目(No.2011CB808703)
长江学者和创新团队发展计划(No.IRT101713018)资助项目
关键词
沸石
磷酸铝
电喷雾质谱
晶化机理
zeolite
aluminophosphate
electrospray ionization mass spectrometry
crystallization mechanism
