Cu-Zr-Ce-O催化剂上CO选择性氧化及再生研究

采用共沉淀法制备了一系列Cu-Zr-Ce-O复合氧化物催化剂，考察了ZrO2加入量、不同再生方法对催化剂CO选择性氧化反应性能的影响，并通过DSC-TPR、XRD和SEM手段对催化剂进行了表征。结果表明，添加ZrO2的Cu1Zr1Ce9Oδ催化剂在160 ℃～200 ℃，具有99％以上的CO转化率，并且催化剂的选择性相对较高。适量ZrO2的加入能够细化催化剂的颗粒，提高催化剂的热稳定性，改变催化剂的聚结方式。经氮气、氢气及氧气再生处理后的Cu1Zr1Ce9Oδ催化剂，催化活性有所不同，其中经氧气处理后的催化剂，表面吸附氧体积分数较高，活性恢复较好。

Studies on selective CO oxidation in hydrogen-rich gas and regeneration of Cu-Zr-Ce-O catalysts

The Cu-Zr-Ce-O mixed oxide catalysts for the selective CO oxidation with various ZrO2 contents were prepared by co-precipitation method and characterized by DSC/TG, XRD and TEM techniques. The effects of ZrO2 loading and different regeneration methods on the activity of Cu-Zr-Ce-O catalysts were investigated. The results showed that higher CO conversion (>99%) and selectivity in a wide temperature range（160 ℃～200 ℃） are obtained when appropriate quantity of ZrO2 is added to Cu1Ce9Oδ. The optimum composition of the catalyst is Cu1Zr1Ce9Oδ. The addition of ZrO2 can improve the thermal stability of the catalyst, decrease the pore size and change the particles' sintering manner simultaneously. The deactivated Cu1Zr1Ce9Oδ catalyst can be refreshed to certain extent by treating at 300 ℃ in nitrogen or 20％H2/N2 atmosphere, while it can be well regenerated in 20％O2/N2 at the same temperature, probably because that the treatment of 20％O2/N2 can enhance the surface absorbed oxygen and well restore the activity of the deactivated catalyst.