催化学报

催化学报 ›› 2008, Vol. 29 ›› Issue (7): 671-676.

• 研究论文 • 上一篇    

二氧化硅负载偏钨酸铵催化剂上邻苯二酚和甲醇气相单醚化反应

邹秀晶1,朱小梅2,李雪梅3,王振旅1,刘钢1,贾明君1,张文祥1   

  1. 1 吉林大学化学学院吉林省表面与界面化学重点实验室, 吉林长春 130012; 2 大连海事大学环境科学与工程学院, 辽宁大连 116026; 3 上海华谊丙烯酸公司, 上海 200137
  • 收稿日期:2008-07-25 出版日期:2008-07-25 发布日期:2012-06-07

Vapour-Phase o-Methylation of Catechol with Methanol on SiO2 -Supported Ammonium Metatungstate Catalysts

ZOU Xiujing1, ZHU Xiaomei2, LI Xuemei3, WANG Zhenlü1, LIU Gang1, JIA Mingjun1*, ZHANG Wenxiang1*   

  1. 1 Key Laboratory of Surface and Interface Chemistry of Jilin Province, College of Chemistry, Jilin University, Changchun 130012, Jilin, China; 2 College of Environmental Science and Engineering, Dalian Maritime University, Dalian 116026, Liaoning, China; 3 Shanghai Huayi Acrylic Acid Co. Ltd, Shanghai 200137, China
  • Received:2008-07-25 Online:2008-07-25 Published:2012-06-07

PDF

1047

被引次数

9

摘要： 考察了SiO2负载的偏钨酸铵催化剂(AMT/SiO2)上邻苯二酚和甲醇气相单醚化反应的性能. 结果表明,经533和573 K焙烧的AMT/SiO2催化剂表现出较高的邻苯二酚转化率(97%)和主产物邻羟基苯甲醚的选择性(91%). 程序升温脱附和吡啶吸附红外光谱结果表明,催化剂表面存在的弱酸-弱碱位是反应的活性中心. 经533 K焙烧制备的催化剂在反应最初46 h内保持较高的稳定性,随着反应时间延长,邻苯二酚的转化率逐渐降低,但主产物的选择性基本保持不变. 扫描电镜和差热热重分析结果表明,催化剂表面积炭是其活性下降的主要原因,采用适当的焙烧处理可以消除大部分积炭,从而部分恢复催化剂活性.

关键词: 邻苯二酚, 甲醇, 单醚化, 邻羟基苯甲醚, 偏钨酸铵, 二氧化硅, 负载型催化剂

Abstract: Catalytic properties of SiO2-supported ammonium metatungstate (AMT) catalysts calcined at different temperatures were investigated for the vapour-phase o-methylation of catechol with methanol. The catalysts calcined at 533 and 573 K showed relatively high catechol conversion (97%) and guaiacol selectivity (91%). The results of temperature-programmed desorption and infrared spectroscopy of adsorbed pyridine revealed that all the tested catalysts possessed weak acid-base sites, which might be the main active sites of the reaction. The stability of AMT/SiO2 calcined at 533 K was studied, and no obvious activity loss occurred within 46 h. With further increase of reaction time, the catalyst activity decreased gradually, but the selectivity for the main product remained almost steady. According to the results of scanning electron microscopy and TGA-DTA thermal analysis, it can be deduced that the coke deposited on the surface of AMT/SiO2 was the main reason for the catalyst deactivation. The catalytic properties of the catalyst could be partially recovered by calcining the used catalyst at a suitable temperature in air.

Key words: catechol, methanol, o-methylation, guaiacol, ammonium metatungstate, silicon dioxide, supported catalyst