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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 .
The structure of Co-Ce-O composite oxide ultrafine particle catalysts and the selective oxidation of 4-methylphenol (PMP) to 4-hydroxybenzaldehyde (PHB) were investigated by TEM, XRD, XPS, BET surface area measurements and microreactor. ) .The results show that the selective oxidation catalytic activity of the Co-Ce-O composite oxide ultrafine particle catalyst is closely related to the size, composition and structure of the catalyst particles. When the atomic ratio of Co / (Co + Ce) is 0.33, The maximum activity of Co-Ce-O composite oxide ultrafine particulate catalyst excellent selective oxidation catalytic activity not only because of its smaller particles, larger specific surface area, but also because highly dispersed Co, Ce components occur , The catalyst has a high concentration of oxygen species adsorbed on the surface of the Co-Ce-O composite oxide sintered at high temperature (> 500 ℃), the specific surface area decreases and the Co-Ce interaction To destruction, resulting in a sharp decline in the catalyst selective oxidation catalytic activity.