物理化学学报 >> 2000, Vol. 16 >> Issue (11): 1028-1034.doi: 10.3866/PKU.WHXB20001112

研究论文 上一篇    下一篇

Co-Ce-O超细微粒催化剂的结构与催化性能

薛蒙伟, 张征林, 范以宁, 陈懿   

  1. 南京大学化学系,南京 210093|东南大学化学化工系,南京 210096
  • 收稿日期:1999-12-01 修回日期:2000-07-17 发布日期:2000-11-15
  • 通讯作者: 范以宁 E-mail:chem612@nju.edu.cn

Structure and Catalytic Selective Oxidation Activity of the Ultrafine Co-Ce-O Oxide Particle Catalysts

Xue Meng-Wei, Zhang Zheng-Lin, Fan Yi-Ning, Chen Yi   

  1. Department of Chemistry,Nanjing University,Nanjing 210093|Department of Chemistry Engineering,Southeast University,Nanjing 210096
  • Received:1999-12-01 Revised:2000-07-17 Published:2000-11-15
  • Contact: Fan Yi-Ning E-mail:chem612@nju.edu.cn

摘要:

应用 TEM、 XRD、 XPS、 BET表面积测试和微型催化反应装置研究了 Co-Ce-O复合氧化物超细微粒催化剂结构及其 4-甲基苯酚 (PMP)选择氧化制 4-羟基苯甲醛 (PHB)的催化性能 .结果表明 Co-Ce-O复合氧化物超细微粒催化剂的选择氧化催化活性与催化剂粒子大小、组成和结构密切相关 ,在 Co/(Co+ Ce)原子比为 0.33时选择氧化催化活性达极大值 .Co-Ce-O复合氧化物超细微粒催化剂优良的选择氧化催化活性不仅仅是因为其粒子较小、比表面积较大 ,而且还因为高分散的 Co、 Ce组份发生了相互作用 ,催化剂具有较高的表面吸附态氧物种浓度 .经高温 ( > 500℃ )处理 ,Co-Ce-O复合氧化物超细微粒发生烧结、比表面积减小且 Co-Ce相互作用遭到破坏 ,从而导致催化剂选择氧化催化活性急剧下降 .

关键词: Co-Ce氧化物, 超细微粒, 4-甲基苯酚, 催化选择氧化, 4-羟基苯甲醛

Abstract:

The structure and catalytic properties of the ultrafine Co-Ce-O complex oxide particle catalysts for selective oxidation of 4-methylphenol(PMP) to 4-hydroxybenzaldehyde(PHB) have been studied by using TEM, XRD, XPS, BET surface area measurements and microreactor tests. It has been shown that the structure, composition and partical size of the ultrafine oxide particles exert great influences on the catalytic properties. Increasing cobalt content in the complex oxide. The catalytic activity for selective oxidation of PMP to PHB increases firstly and then decreases remarkably. It has been found that the higher activity of the ultrafine Co-Ce-O complex oxide particles catalysts for selective oxidation of PMP to PHB was not only correlated to their higher surface areas of the ultrafine particles but also correlated to the interaction between Co oxide and Ce oxide. Thermal treatments at higher temperatures result in sintering of the particles and destroy the interaction between Co oxide and Ce oxide, leading to remarkable decrease in the catalytic selective oxidation activity.

Key words: Co-Ce oxides, Ultrafine particles, 4-methylphenol, Catalytic selective oxidation, 4-hydroxybenzaldehyde