催化学报

催化学报 ›› 2011, Vol. 32 ›› Issue (6): 1011-1016.DOI: 10.3724/SP.J.1088.2011.01235

• 研究论文 • 上一篇    下一篇

酸处理活性炭对其负载的 RbNO3-KF 催化剂气相合成 C2F5I 反应性能的影响

冒爱琴 1,2,3, 王华 1, 谈玲华 1, 蔺相阳 1, 潘仁明 1,*   

  1. 1南京理工大学化工学院, 江苏南京 210094; 2安徽工业大学材料科学与工程学院, 安徽马鞍山 243002; 3安徽工业大学安徽省金属材料与加工重点实验室, 安徽马鞍山 243002
  • 收稿日期:2010-12-15 修回日期:2011-03-01 出版日期:2011-06-21 发布日期:2014-10-31

Effects of Acid Treatment of Activated Carbon on Catalytic Performance of RbNO3-KF/AC Catalyst for C2F5I Gas-Phase Synthesis

MAO Aiqin1,2,3, WANG Hua1, TAN Linghua1, LIN Xiangyang1, PAN Renming1,*   

  1. 1School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, Jiangsu, China; 2School of Materials Science and Engineering, Anhui University of Technology, Ma’anshan 243002, Anhui, China; 3Anhui Key Laboratory of Metal Materials and Processing, Anhui University of Technology, Ma’anshan 243002, Anhui, China
  • Received:2010-12-15 Revised:2011-03-01 Online:2011-06-21 Published:2014-10-31

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摘要： 对活性炭 (AC) 进行酸处理能够改变表面含氧官能团, 从而加强金属前驱体与活性炭载体的锚固作用, 改变催化剂的分散度和表面碱性. 采用 HCl, HNO3 和 HF 分别对 AC 进行处理, 制得一系列 AC 负载的 RbNO3-KF 催化剂, 考察了它们在气相合成 C2F5I 反应中的催化性能. 采用 N2 吸附-脱附、Boehm 滴定、CO2 程序升温脱附、X 射线衍射、X 射线光电子能谱和元素分析对催化剂进行了表征. 结果表明, AC 经 HCl 处理后 RbNO3-KF/AC 催化剂具有较高的分散度和适中的弱碱性, 有利于气相催化合成 C2F5I. 各催化剂分散度大小顺序为: RbNO3-KF/AC(HNO3) > RbNO3-KF/AC(HF) > RbNO3-KF/AC(HCl) > RbNO3-KF/AC. 该顺序与相应载体表面的酸性和官能团变化趋势一致, 但与催化剂表面的碱性并无对应关系. 催化剂表面碱性与 AC 表面含氧官能团和表面碱性有关.

关键词: 活性炭, 酸处理, 表面含氧官能团, 硝酸铷, 氟化钾, 五氟碘乙烷

Abstract: Modification of activated carbon (AC) with different acid solution might result in various surface oxygen groups, which can enhance the anchoring interaction between AC support and metal precursor and change the dispersion and basicity of the catalyst. The influence of HCl, HNO3, and HF treatment on RbNO3-KF/AC catalyst in the gas-phase synthesis of C2F5I by reaction of C2HF5 with I2 and O2 was studied. The pore structure and the surface chemical properties of the AC support were investigated by N2 adsorption-desorption and Boehm titration. The dispersion and basicity of the catalyst before and after acid treatment were investigated by CO2 temperature-programmed desorption, X-ray diffraction, X-ray photoelectron spectroscopy, and inductively coupled plasma atomic emission spectrometry. It was found that after the HCl treatment, the RbNO3-KF/AC(HCl) catalyst has high dispersion and moderately basicity, which is helpful for the enhancement of catalytic activity for C2F5I synthesis. The catalyst dispersion is in the order: RbNO3-KF/AC(HNO3) > RbNO3-KF/AC(HF) > RbNO3-KF/AC(HCl) > RbNO3-KF/AC. The same sequence is also observed for the amount of acid surface oxygen groups on AC, but not for the weak basicity of the catalyst. The key role of acid treatment on the AC surface chemistry and moderate basic sites, which are closely related to catalyst dispersion and basicity, is examined to rationalize these findings.

Key words: activated carbon, acidic treatment, surface oxygen group, rubidium nitrate, potassium fluoride, pentafluoroethyl iodide