CuO/TiO_2和CuO-ZrO_2/TiO_2催化剂对NO+CO反应性能的影响  

Effect of CuO/TiO_2 and CuO-ZrO_2/TiO_2 Catalysts on NO+CO Reaction Properties

作　　者：蒋晓原[1] 丁光辉[1] 楼莉萍[2] 李供省[1] 陈英旭[2] 郑小明[1] 

机构地区：[1]浙江大学理学院催化研究所,杭州310028 [2]浙江大学环资学院环境工程系,杭州310029

出　　处：《复旦学报（自然科学版）》2003年第3期457-462,共6页Journal of Fudan University：Natural Science

摘　　要：以TiO2为载体,采用浸渍法制备了不同负载量的CuO/TiO2和CuO ZrO2/TiO2催化剂,并在色谱 微反装置上考察了催化剂对NO+CO反应性能,并通过TPR、XRD和NO TPD技术对上述催化剂进行了表征.结果表明催化剂经500℃H2气氛中还原1h与空气氛中处理的相比,活性有明显的改善,CuO/TiO2(6%)对NO完全转化的T99%=325℃,而CuO ZrO2/TiO2(6%,10%)对NO完全转化的T99%=300℃;TPR结果表明CuO/TiO2在TPR过程中出现4个还原峰,而CuO ZrO2/TiO2只有2个还原峰,说明ZrO2的引入使CuO在TiO2上的还原物种发生了变化;空气氛处理的CuO/TiO2催化剂XRD检测到的是CuO的特征衍射峰,而H2气氛处理是金属Cu的特征衍射峰;NO TPD结果表明两种气氛处理的催化剂,NO吸附在其上的热脱附产物中质谱能检测到4种物种(NO,N2O,N2和O2),低温脱附物种为吸附在弱位上的NO,高温脱附物种则是吸附在强位上的NO;CuO/TiO2上引入ZrO2后NO的脱附峰温明显降低,这表明NO在CuO ZrO2/TiO2表面的分解活性大于NO在CuO/TiO2表面的分解活性;NO+CO反应低温时形成中间产物N2O,高温时产生N2;NO TPD脱附峰温与两种气氛处理的催化剂活性有很好的对应关系,且NO在催化剂表面的解离是NO+CO反应的速控步骤.CuO/TiO2 and CuOZrO2/TiO2 catalysts of difference CuO loading amounts are prepared by the impregnation method. Different amount of CuO and ZrO2 are loaded on TiO2. The activity for NO+CO reaction is investigated, and structure and reductive properties of various CuO/TiO2 and CuOZrO2/TiO2 catalysts are characterized by means of TPR, XRD and NOTPD technology. Experimental results show that the catalysts treated in H2 atmosphere 500 ℃ for 2 h has the catalytic activity improved evidently as compare with the catalysts were treated in air atmosphere 500 ℃ for 2 h, the NO complete conversion temperature T99%=325 ℃ for CuO/TiO2(6%) catalysts, T99%=300 ℃ for CuOZrO2/TiO2(6%, 10%) catalysts. TPR data show that there are four TPR peaks of CuO/TiO2, but only two TPR peaks of CuOZrO2/TiO2, this indicates that the addition of ZrO2 makes CuO reduction species on TiO2 change; XRD analysis show the catalysts treated in air atmosphere, display the CuO diffraction peaks; whereas the catalysts were treated in H2 atmosphere, display the metal Cu diffraction peaks; NOTPD profile exhibits four desorption species(NO, N2O, N2 and O2) during the thermal desorption of NO adsorbed on either CuO/TiO2 or CuOZrO2/TiO2 with the catalysts treated at two kinds of atmosphere, there are two types of adsorption states of NO on the catalyst's surface, desorption species at low temperatures are the NO of adsorption on weak sites, desorption species at high temperature are the NO of adsorption on strong sites; the addition of ZrO2 to CuO/TiO2 makes NO dissociation peaks to shift toward the low temperature, indicating that the NO decomposition activity of CuOZrO2/TiO2 is higher than that of the CuO/TiO2 catalysts. The NO+CO reaction go

关 键 词：CuO/TiO2和CuO-ZrO2/TiO2催化剂 NO+CO反应 NO-TPD 

分 类 号：O643.32[理学—物理化学]