三氟碘甲烷的合成及机理  

Synthesis and Mechanism of CF_3I

作　　者：李勤华[1] 谈玲华[1,2] 杭祖圣[1,2] 冒爱琴[1] 潘仁明[1] 

机构地区：[1]南京理工大学化工学院,江苏南京210094 [2]南京工程学院材料工程学院,江苏南京211167

出　　处：《南京理工大学学报》2011年第6期863-866,共4页Journal of Nanjing University of Science and Technology

基　　金："十一五"国家科技支撑计划(2008BAK40B02);江苏省2009年度普通高校研究生科研创新计划(CX09B_095Z)

摘　　要：该文采用气相催化法以三氟甲烷(CHF3)和碘为原料合成了三氟碘甲烷(CF3I)。对产物进行气相色谱-质谱、气相色谱、傅里叶变换红外光谱和分子量等测试,并对使用前后的催化剂进行BET(Brunauer、Emmett和Teller)比表面积测试和热重分析。结果表明:反应生成CF3I,转化率达到52.3%,选择性达到56.2%。催化剂的比表面积和孔体积降低,分别由反应前的776.8 m2/g和0.38 cm3/g下降到反应后的359.2 m2/g和0.18 cm3/g。反应后的催化剂在250～350℃之间失重率达到12wt%,说明在反应过程中催化剂表面产生积炭。根据二氟卡宾(CF2)的歧化机理和催化剂的表面积炭现象,提出了产物CF3I和副产物可能的形成机理。Trifluoroiodomethane（CF3I）is synthesized via the vapor-phase catalytic method using trifluoromethane（CHF3）and iodine（I2）.The product is characterized by gas chromatography-mass spectrometry,gas chromatography,Fourier transform infrared spectroscopy and molecular weight determination.The catalyst is investigated with the BET（Brunauer,Emmett and Teller）specific surface area method and thermogravimetry.The results show that the conversion of CHF3 is 52.3% and the selectivity of CF3I is 56.2%.The BET surface area and the pore volume of catalyst are 776.8 m2/g and 0.38 cm3/g before the reaction and decrease to 359.2 m2/g and 0.18 cm3/g after the reaction.The weight loss of the used catalyst reaches 12wt% over the temperature range of 250~350 ℃,which shows that coke forms in the process of reaction.The possible mechanism of the product and by-products is proposed based on the difluorocarbene（CF2）disproportionate and coke formation.

关 键 词：三氟碘甲烷 合成 机理 二氟卡宾 

分 类 号：O643.36[理学—物理化学] TQ426.94[理学—化学]