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Syntheses and Structures of Novel Microporous Germanate Molecular Sieves

Author: ZhouYaMing
Tutor: ZhaoDongYuan
School: Fudan University
Course: Inorganic Chemistry
Keywords: Microporous materials Tellurite Hydrothermal Synthesis Solvothermal Synthesis Crystal structure
CLC: TQ424
Type: PhD thesis
Year: 2003
Downloads: 435
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Abstract

Inorganic microporous materials have important applications in the field of host-guest chemistry of catalysis, gas adsorption and separation, nonlinear optical materials, semiconductor materials, chemical micro-reactor. The new topology and chemical composition of the design, synthesis and characterization of microporous compounds has been an issue of concern. Traditional aluminosilicate zeolites has been extremely broad and important applications in the industrial process, but in the system of hydrothermal and solvothermal germanate zeolite-like materials synthesis study also rare. The tellurite having very interesting structural features, it's \Studied in detail the synthesis of the zeolite material of the germanium salts. Our work is not only limited to the introduction of the new composition of the elements in the zeolite structure is known and, more importantly, to explore synthetic methods for the new topology to obtain unknown. Solvothermal and hydrothermal conditions, respectively, using organic amines and inorganic ions as structure-directing agent successfully synthesized more than ten kinds of germanium salts zeolite molecular sieves, and were studied by single-crystal structure analysis of its structure. These new inorganic microporous materials exhibit many unique structural features such as a spiral chain and odd-membered ring structure. Ternary ring structure exists in these materials, research has proved that the structure of the three-membered ring is one of the key to the formation of large pores and low skeletal density. Tellurite structure, the the skeleton constitutes addition to tetrahedron outside GeO4, there GeO5 trigonal bipyramidal, GeO6 octahedron, which bodes well germanate zeolites may have a richer topology. Triamine N, N-dimethyl formamide (DMF) as solvent, ethyl amine (TREN) as a template agent, synthesized for the first time by having a 24-membered ring King Kong tellurite Zeolite FDUs-4. FDU-4 has by far the largest structural units of 24-membered ring; It is the first reported germanate zeolite has a large hole; its matrix density 11. 1 is the lowest one of the skeletal density, which will be synthesized; the FDUs-4 structure of 24-membered ring and 12-membered ring into a honeycomb hexagonal close-packed arrangement, the structural characteristics similar to the mesoporous zeolite having a crystal Wall a mesoporous material having a different pore size of the mesoporous material was provided. 1,4 - dioxane as solvent, TREN template agent, synthetic to has Ge7 cluster new germanate zeolite FDG-9, which has a one-dimensional 7-membered ring channels in the 110 direction. Tellurite Zeolites of ethylene glycol as the solvent, another new tellurite zeolite FDG-10 synthesis of 1,6 - hexanediamine templating agent, it is the first one having a 11-membered ring. Form FDG-10 Ge6 clusters first discovered GeO3's triangular pyramid structure unit. Were used TMAOH and ethylenediamine as template synthesis of three SOD structure germanate zeolites FDG-11 FDG-12 FDG-13. Ethylenediamine strong template effect, FDG-12 and FDG-13 SOD structure has very low symmetry. SOD symmetry of the structure by FDG-11 cubic complex mouth people learn Bo on their discretionary the defined Abstract don square crystal (symmetry) transformation in order to FDG-12 and FDG Diao 3 the triclinic (symmetry), which fully be described in a structure-directing effect of the organic amine in the inorganic skeleton templating agent. To the aminoethyl BISHAMON lfe and Na \with UCSB-gL having similar topology, we first synthesized in a fluorine-free medium in this topology. FDG-17 having a novel layered structure constitute FDG1 layer to have a certain thickness, a six-membered ring pore throughout the layer. in colonies germanium - phosphoric acid system to 1,3 - propanediamine (PDA) as templating agent, in a different solvent and the ratio of raw materials, were synthesized out of the one-dimensional chain phosphorylation JARL and phosphate marry germanium microporous material, GeGaPO-PDA phosphate marry germanium zeolite first synthesized under solvothermal conditions in GaPO-PDA connected by hydrogen bonds between the chain of phosphate married to form a two-dimensional layered structure between layers through templating agent to form a three-dimensional structure and the structure characteristics of guiding significance for the study of the different dimension of microporous materials synthesis and transformation process has charge matching principle and the main object symmetry matching principle, but also synthesis of germanium acid sticky microporous structure. FDG-3 a-quartz structure with helical chains; FDG-4 with a double spiral) ie with UCSB-7 structure, of which the the FDG-4Ge is the first synthesis of pure the structure of the germanium UCSB-7; FDG-5 and FDG Seventh mountain the same secondary structural elements pBU of) constitute the the SBU different connection caused a clever FDG and FDG seven completely different spatial structure; P ** -8 * S * -14 the same topology, however, F ** -8 synthesis of fluorine-free medium, it has more than ASU-14 higher symmetry. these unique structural features and the new germanium knees molecular sieve materials synthetic success will greatly factory Billiton points in sieve synthesis field range of difficulties, to explore the application of molecular sieve materials, the plant hair design novel points sieve structure have important theoretical significance and application value.

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