Synthesis And Catalytic Performance Of Microporous Materials By Microwave Irradiation

Inorganic open-framework materials such as molecular sieves have uniform pore distribution,so the compounds have been extensively used in many industrial processes such as catalysis,adsorption and separation.Therefore,the study of the relationship between the synthesis conditions of inorganic open-framework material and the structure of the product is one of the most important fields for the synthesis material field.In this paper,microwave assisted hydrothermal synthesis method have been studied in an open-framework zinc phosphate compounds and aluminosilicate system,including the main findings as following:1.Zinc acetate,imidazole,phosphoric acid were added into deionized water in order,and stirred to form a transparent solution.The mixture was heating under the reaction temperature by microwave radiation.1-D structure,Zn（C₃N₂H₄）HPO₄（Compound（40））,and 2-D structure,Zn₄P₃O₁₁（OH）·3C₃N₂H₄（Compound（40）（40））,were obtained in the same reaction system.The structures of products were different,but the structures have certain relevance.2.The reaction conditions of phaseⅠandⅡwere investigated in detail.The crystallization conditions of the two compounds have a close relationship.When the crystallization temperature was low or the reaction time was short,CompoundⅠcan be obtained.With the same composition of reaction mixture,CompoundⅡcan be synthesized by increasing the crystallization temperature or prolonging the reaction time.3.The other reaction conditions were discussed as well,such as the ratio of H₂O/Zn（OAc）₂ in the mixtures,the ratio of H₃PO₄/Zn（OAc）₂ in the mixtures and zinc sources.Found that when the ratio of H₂O/Zn（OAc）₂ was low in a certain range,CompoundⅠcan be obtained.And CompoundⅡcan be synthesized by increasing the ratio of H₂O/Zn（OAc）₂.In contrast,when the ratio of H₃PO₄/Zn（OAc）₂ was low,Compound（40）I can be obtained.4.Choose a classic type of molecular sieves（ANA type）in the aluminosilicate molecular sieve system toresearch.By changing the synthesis conditions,such as reaction temperature,reaction time and silica-alumina ratio,to explore the relationship between the synthesis conditions and the structure and morphology of products.The main findings as following: when the silica-alumina ratio is large,pure ANA zeolite can be synthesized;reaction temperature is changed and when the temperature is increasing in a certain range,the ANA zeolite products are more pure;with the same reaction temperature,ANA zeolite can be synthesized rapidly by prolonging the reaction time;ANA zeolite can be obtained in only 30 min when the reaction conditions are suitable.