摘要
以ZrO2为载体、采用不同的浸渍次序制备了3种CuO-CeO2/ZrO2催化剂并在不同的温度(500,650和800℃)下进行焙烧,利用X射线衍射(XRD)、程序升温还原(H2-TPR和CO-TPR)及CO程序升温脱附(CO-TPD)技术对所制备的催化剂进行了表征,并采用色谱流动法考察了其催化CO低温氧化反应性能。结果表明,当焙烧温度为650℃时,3种催化剂的CO催化氧化活性均最佳,且三者的催化活性大小顺序为:CuO/CeO2/ZrO2>CuO-CeO2/ZrO2>CeO2/CuO/ZrO2。结合催化剂的表征和活性测试结果,我们认为高分散的CuO是CO的吸附中心,有利于CO的低温氧化反应,而大颗粒的CuO几乎对CO没有吸附作用,不利于CO的低温氧化反应。在3种催化剂中,CuO/CeO2/ZrO2催化剂具有最佳的低温还原特性和最大的CO2脱附峰面积,相应地具有最佳的催化氧化活性。
Three types of CuO-CeO2/ZrO2 catalysts were prepared with ZrO2 as the support by different impregnation sequences, and were calcined at different temperatures （500, 650 and 800 ℃）. These catalysts were characterized by X-ray diffraction （XRD）, temperature-programmed reduction by H2 or CO （Hi-TPR, CO-TPR）, and temperature- programmed desorption of CO （TPD） techniques. Their catalytic activities for low temperature CO oxidation were investigated using a microreactor-gas chromatograph system. The results indicate that the catalytic activity for the catalysts calcined at 650 ℃ is the highest and is in the following order： CuO/CeO2/ZrO2〉CuO-CeO2/ZrO2〉CeO2/CuO/ZrO2. Based on the results of characterizations and catalytic activity measurements, we propose that the well- dispersed CuO is the center for adsorption of CO and is favorable for low-temperature CO oxidation, and the bulk CuO contributes little to the catalytic activity because of its inability to adsorb CO. Among the three types of catalysts, CuO/CeO2/ZrO2 has better low-temperature redox property, larger CO2 desorption peak area and higher catalytic activity for CO oxidation.
出处
《无机化学学报》
SCIE
CAS
CSCD
北大核心
2012年第7期1353-1359,共7页
Chinese Journal of Inorganic Chemistry
基金
上海市教委曙光跟踪计划(10GG23)和上海市教委重点学科建设(J51503)资助项目
