物理化学学报 >> 2014, Vol. 30 >> Issue (6): 1163-1168.doi: 10.3866/PKU.WHXB201404081

催化和表面科学 上一篇    下一篇

磷酸铝负载钾催化剂表面酸碱性质对邻苯二酚O-单醚化催化性能的影响

刘钢1, 杨录新2, 吴淑杰1, 贾明君1, 张文祥1   

  1. 1 吉林大学化学学院, 长春130012;
    2 营口天元化工研究所股份有限公司新产品研发应用部, 辽宁营口115004
  • 收稿日期:2014-01-24 修回日期:2014-04-08 发布日期:2014-05-26
  • 通讯作者: 张文祥 E-mail:zhwenx@jlu.edu.cn
  • 基金资助:

    国家自然科学基金(21003059),吉林省科技发展计划(20130101014JC)和中央高校基本科研业务费专项资金资助项目

Influence of Acid-Base Properties of K-Loaded Aluminophosphate Catalysts on Their Catalytic Behavior in the O-Methylation of Catechol

LIU Gang1, YANG Lu-Xin2, WU Shu-Jie1, JIA Ming-Jun1, ZHANG Wen-Xiang1   

  1. 1 College of Chemistry, Jilin University, Changchun 130012, P. R. China;
    2 Technical Department, Yingkou Tianyuan Chemical Research Institute Co., Ltd., Yingkou 115004, Liaoning Province, P. R. China
  • Received:2014-01-24 Revised:2014-04-08 Published:2014-05-26
  • Contact: ZHANG Wen-Xiang E-mail:zhwenx@jlu.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (21003059), Development Project of Science and Technology of Jilin Province, China (20130101014JC), and Fundamental Research Funds for the Central Universities, China.

摘要:

采用浸渍法制备了磷酸铝负载钾催化剂,通过X射线衍射(XRD)、傅里叶变换红外(FTIR)光谱、氮吸附实验、CO2和NH3的程序升温脱附(CO2-TPD和NH3-TPD)等手段对催化剂进行了表征. 结果表明钾高分散在磷酸铝样品表面;加入少量钾后样品表面的酸中心和碱中心的量同时减少;而随着钾量的增加表面碱量没有明显变化,酸量显著下降. 催化剂在以邻苯二酚和甲醇为原料气相法一步合成愈创木酚反应中的活性结果显示:加入少量钾的样品上愈创木酚的选择性显著提高,随着钾量的增加,愈创木酚的选择性进一步增加,邻苯二酚的转化率降低. 关联表征结果:催化剂表面弱酸中心对提高邻苯二酚的转化率起着重要作用,而表面弱碱中心对提高愈创木酚的选择性有利.

关键词: 磷酸铝, 邻苯二酚, 愈创木酚, 弱酸弱碱, 钾负载

Abstract:

K-loaded aluminophosphates prepared by impregnation were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, N2 adsorption, and NH3 as well as CO2 temperatureprogramed desorption (NH3-TPD, CO2-TPD). The results show that potassium was highly dispersed on the surface of the aluminophosphates. The amount of surface acidic and basic sites decreased upon adding a small amount of potassium. With an increase in potassium, the amount of surface acid sites decreased and the amount of surface base sites did not obviously change. Vapor-phase O-methylation of catechol with methanol was carried out to investigate the catalytic performance of the K-loaded aluminophosphates. Selectivity toward guaiacol obviously increased when a small amount of potassium was added. With an increase in the potassium content, selectivity toward guaiacol increased further and the conversion of catechol decreased. Combined with the characterization results, the surface weak acidic sites play an important role in improving the conversion of catechol and the surface weak basic sites are suitable for improving selectivity toward guaiacol.

Key words: Aluminophosphate, Catechol, Guaiacol, Weak acid and base, K-loading

MSC2000: 

  • O643