硝基修饰MOF-5材料的制备及催化氨基甲酸酯热分解!  

Synthesis of Nitro-modified MOF-5 and Its Application on Catalyzing the Thermal Decomposition of Carbamates

作　　者：张毅[1,2] 杨先贵[1] 王庆印[1,2] 姚洁[1] 胡静[1] 王公应[1] 

机构地区：[1]中国科学院成都有机化学研究所,成都610041 [2]中国科学院大学,北京100049

出　　处：《高等学校化学学报》2014年第3期613-618,共6页Chemical Journal of Chinese Universities

基　　金：国家科技支撑计划重大项目(批准号:2006BAC02A08);四川省青年科技创新团队项目(批准号:2013TD0010);中国科学院知识创新工程项目(批准号:KGCX2-YW-215-2)资助~~

摘　　要：采用直接混合法在室温下制备了含硝基的金属-有机骨架材料MOF-5-NO2,并采用X射线衍射分析,红外光谱,N2等温吸附和扫描电子显微镜对其进行了表征.结果表明,MOF-5-NO2具有与MOF-5相似的晶体结构和表面形貌,二者都具有高比表面积及微孔特性,但由于硝基的吸电子效应,MOF-5-NO2比MOF-5具有更强的Lewis酸性,因而对氨基甲酸酯热分解制备异氰酸酯的反应具有良好的催化活性.在无溶剂条件下,MOF-5-NO2使苯氨基甲酸甲酯热分解的反应速度显著提高,催化剂转化频率达到ZnO的7倍以上;二苯甲烷二氨基甲酸苯酯热分解的中间产物减少,二苯甲烷二异氰酸酯的收率达到81.6%.Metal-organic frameworks （ MOFs ） are a new class of porous materials that are constructed from transition metal ions and organic ligands, and have potential applications in catalysis, separation and gas storage. MOF-5-NO2 , a metal-organic framework with nitro group, was synthesised by the direct mixing method at room temperature. Characterized by XRD, FTIR, N2 adsorption and SEM, the crystalline structure and morphology of MOF-5-NO2 were found resembled that of MOF-5, and both the MOFs exhibited microporo-sity with high specific surface area. However, the Lewis acidity of MOF-5-NO2 was stronger than that of MOF-5 for the electron withdrawing effect of -NO2 , which was one of the reasons for the high activity of MOF-5-NO2 on the synthesis of isocyanates by the thermal decomposition of carbamates. Under solvent-free condition, MOF-5-NO2 significantly accelerated the reaction rate of the decomposition of methyl N-phenyl car-bamate, and the turnover frequency（TOF） was seven times higher than that on ZnO. The intermediate product of the decomposition of methylene diphenyl di（ phenylcarbamate） was decreased, and the yield of methylene diphenyl diisocyanate reached 81.6%. In conclusion, MOF-5-NO2 prepared by the direct mixing method is a very effective catalyst for the thermal decomposition of carbamates, and is potentially better suited for other ca-talyses by modified with appropriate groups.

关 键 词：金属-有机骨架材料 硝基 氨基甲酸酯 热分解 LEWIS酸 

分 类 号：O643.3[理学—物理化学]