Hydrothermal synthesis of organically modified metal phosphates and borates.

摘要

Crystalline inorganic oxides are an important class of materials with many technological uses. Chapter 1 gives a brief history of this area with special focus on the formation of microporous metal oxides such as the zeolites and related AlPO family of aluminophosphates, as well as the fundamental parameters of hydrothermal synthesis used and the key methods used for characterization of these types of solid. In this work we have sought to extend the range and composition of such open framework materials, which have commercial importance in catalysis and separation technologies, to include examination of indium phosphates, mixed-metal phosphates, zirconium phosphates, vanadophosphates, vanadomolybdates, and vanadoborate cluster solids. The rationale is to find new stable oxide frameworks or clusters, for which REDOX active centers can be incorporated and leading to new catalytic applications complementary to existing phases.; The experimental work in this thesis describes the formation and isolation of over 35 new crystalline solids from these above families in which the structure and arrangement of inorganic oxide components, such as metal phosphate or borate, is varied through their synthesis in the presence of organic structure directing groups.; Chapter 2 describes the synthesis of 19 new organically modified group 13 phosphates.; Chapter 3 describes our parallel studies on group IV phosphate phases of Zr and Ti and five new phases are reported.; Chapter 4 describes our attempts to isolate group V, and VI mixed metal phosphate solids and five new compounds are reported.; Chapter 5 describes our work on vanadium (IV) borates, which again typically take the form of cluster sub units.; In summary we have explored several relatively undeveloped areas of metal oxide solid and in each case have found that depending on synthesis conditions, the inorganic component can be co-crystallized with organic co-components which modulate the structure through supra-molecular effects. In the case of cluster work less obvious dependence is seen for the counter ion in vanadoborate chemistry, however for the vanado-molybdo-phosphate system the selective precipitation of particular clusters from a complex ‘soup’ of similar cluster ions appears to be possible through variation of the organic cation. (Abstract shortened by UMI.)