Abstract:

        Hexadecyl trimethyl ammonium bromide was employed as template agent , sodium silicate as the silica source and the solution of iron nitrate were added in the synthesis process under 55 ℃, the mesoporous molecular sieve Fe -MCM -41 was synthesized using the hydrothermal method, which was crystallized for 48 hours under 160 ℃.The products were characterized by XRD, nitrogen adsorption and desorption , IR and TG -DTA .The results show that the molecular sieve has the favourable crystal structure and the iron has been located in framework of the molecular sieve .Fe -MCM -41 molecular sieve was used as catalyst and oxygen gas as oxidant for the selective oxidation of cyclohexane .The effects of temperature , time and pressure on cyclohexane selective oxidation reaction were investigated .The conversion of cyclohexane is increased as the increasing of time and temperature , but the pressure has little effect on it .Under the conditions of reaction time being 6 hours, temperature being 180 ℃, and pressure being 2 .5MPa , the conversion of cyclohexane is 14 .0 %, the selectivity of cyclohexanone is 9 .5 %, and the selectivity of cyclohexanol is 90.5 %.

Key words: 　Fe -MCM -41 molecular sieves, 　Hydrothermal synthesis , 　Selective oxidation, 　Cyclohexane

摘要：         用十六烷基三甲基溴化铵为模板剂, 水玻璃为硅源, 在55 ℃水热合成过程中加入硝酸铁溶液, 在160℃晶化48 h, 合成出Fe -MCM -41 分子筛。并用粉末X -射线衍射、N₂ 吸附-脱附、红外光谱及差热-热重分析等手段进行了表征。结果表明, 合成的分子筛具有良好的晶体结构, 铁已经进入分子筛骨架。利用Fe -MCM -41分子筛作为催化剂, 以氧气为氧源, 考察了温度、时间、压力等因素对环己烷选择性氧化反应的影响。环己烷的转化率随着时间和温度的增加而增加, 但压力的增加对其影响不大。在反应6 h , 温度为180 ℃, 反应压力为2 .5 MPa 的条件下, 环己烷的转化率为14 .0%, 环己酮的选择性为9 .5 %, 环己醇的选择性为90 .5 %。

关键词: Fe -MCM -41 分子筛,  , 　水热合成, 　选择性氧化, 　环己烷