Zeolitic germanosilicate analogue to pharmacosiderite crystallized in an acidic medium  

作　　者：Guangying Fu Qiaolin Lang Xiaolong Liu Haonuan Zhao Yiqing Sun Lei Zhao Ahmed Omran Peng Lu Xiaobo Yang Bing Yu Valentin Valtchev 

机构地区：[1]The ZeoMat Group,Qingdao Institute of Bioenergy and Bioprocess Technology,Chinese Academy of Science,Laoshan District,266101 Qingdao,China [2]College of Chemistry and Chemical Engineering,Qingdao University,266071 Qingdao,China [3]Normandie University,ENSICAEN,UNICAEN,CNRS,Laboratoire Catalyse et Spectrochimie,F-14000 Caen,France

出　　处：《Green Carbon》2023年第2期185-192,共8页绿碳（英文）

基　　金：support provided by the Shandong Energy Institute(SEI S202107);Nature Science Foundation of Shandong Province(ZR2022MB053 and ZR2022QB216).

摘　　要：Zeolites are typically synthesized in alkaline or fluoride-containing near-neutral media.Sophisticated organic structure-directing agents have been investigated for such systems with the aim of discovering materials with unprecedented structures and properties for novel technical applications.In contrast,zeolite crystallization in strongly acidic media has yet to be explored.This study demonstrates that a zeolitic silicate phase crystallizes from acidic gels using trimethylamine as an organic additive with the composition 1 SiO_(2):0.3 TMA:0.3 HCl:0.15 HF:55 H_(2)O:(0.1-0.4)GeO_(2).This phase has an interrupted four-connected framework analog to the octahedron/tetrahedron-mixed framework of the mineral family pharmacosiderite.In comparison to the pharmacosiderite-type HK_(3)(Ge_(7)O_(16))(H_(2)O)_(4),the four GeO_(6)-octahedra forming the central[HGe_(4)O_(4)O_(12)]-cluster are replaced by four SiO_(4)-tetrahedra in a[Si_(4)O_(6)(OH)2.89]-unit in the new phase.However,the structure is distorted and may contain connectivity and point defects;thus,healing by the occasional incorporation of GeO_(6)-units is necessary.The refined unit cell has a cubic symmetry,space group P-43m(#215),with a=7.7005(1)Å.Acidic-medium synthesis is a useful way to find new zeolites that move in a fundamentally different direction from sophisticated organic structure-directing agents.

关 键 词：Zeolite synthesis in acidic medium New germanosilicate zeolite 4-connected analogue of pharmacosiderite Structure analysis Structure-directing agents 

分 类 号：O62[理学—有机化学]