采用浸渍法合成了Cu-Mn/g-Al2O3催化剂,通过XRD、BET、H2-TPR和XPS等方法对经不同温度(300~600℃)焙烧的催化剂进行表征,采用固定床管式反应装置考察了焙烧温度对催化剂催化氧化甲苯的影响,并讨论活性组分、表面Cu+/(Cu++Cu2+)和Mn4+/(Mn4++Mn3+)摩尔比值与催化剂活性的关系。结果发现,550℃焙烧温度的催化剂活性最好,氧化能力最强,其转化率为95%时对应的反应温度T95(286℃)最低, CO2的选择性达100%。在550℃焙烧时生成的Cu1.4Mn1.6O4新相以及催化剂表面中相对含量更高的Cu+和Mn4+是催化剂具有高活性的主要原因。
Cu-Mn/g-Al2O3 catalysts were prepared by impregnation method and calcined at different temperatures (300-600℃), which were characterized by XRD, BET, H2-TPR and XPS. Their performances for catalytic oxidation of toluene were evaluated in a fixed-bed tubular reactor, and the correlation of catalytic activity with active phases or mole ratios of both Cu+/(Cu++Cu2+) and Mn4+/(Mn4++Mn3+) was discussed. Among all catalysts, the Cu-Mn/g-Al2O3 catalyst calcined at 550℃ shows the best catalytic activity, with a lowest reaction temperature (T95is286℃) and 100% selectivity of CO2. The generation of new phase (Cu1.4Mn1.6O4) and more amount of Cu+ and Mn4+ ions present on the surface of the catalyst calcined at 550℃ are responsible for its high activity.
参考文献
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%