MnO_x和CeO_2催化剂在含NO气氛中氧化模拟碳烟的研究  

Oxidation of model soot over MnO_x and CeO_2 catalysts in the presence of NO

作　　者：付名利[1,2] 林俊敏[1] 于润芃[1] 张明[1] 叶代启[1,2,3] 

机构地区：[1]华南理工大学环境与能源学院,广州510006 [2]广东省大气环境与污染控制重点实验室,广州510006 [3]大气污染控制广东高校工程技术研究中心,广州510006

出　　处：《环境科学学报》2013年第8期2134-2142,共9页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金项目(No.51108187;50978103);大气污染控制广东高校工程技术研究中心资助项目(No.GCZX-A0903);中央高校基本科研业务费(No.2012ZM0041;2011ZM0048)~~

摘　　要：用沉淀法制备了MnOx和CeO2两种催化剂并用于氧化模拟碳烟.XRD、BET、O2-TPD和NO-TPD表征结果表明,CeO2的比表面积和NOx吸附容量更大,而MnOx则具有更多的氧物种(晶格氧O2-).TPO结果表明,气氛中引入的NO明显促进了碳烟的氧化.在无催化剂、加入CeO2和MnOx3种情况下,模拟碳烟的起燃温度Ti分别降低了38、41和101℃.DRIFTs结果表明,催化剂活性氧物种和反应过程中生成的NO-3是NO促进碳烟燃烧的关键因子.可能的反应路径为:低温富氧条件下气相中的O2吸附在催化剂表面上,丰富的活性氧物种(如O2-、O-2和O-)得到激活和转化,进而将弱吸附NO2和活性NO*2氧化成NO-3;在高温时则释放出活性很强的NO*2和O-,因而能促进碳烟氧化,其中间产物为碳氧复合物C(O).MnOx and CeO2 were prepared by precipitation method as catalysts for the oxidation of model soot.Characterization measurements of XRD,BET,O2-TPD and NO-TPD demonstrated that CeO2 exhibited greater surface area and NOx adsorption capacity,while more oxygen species（lattice oxygen O2-） were detected in MnOx.TPO test revealed that NO in the feeding gases remarkably promoted soot oxidation.The ignition temperature Ti for soot oxidation decreased by 38 ℃ without addition of any catalyst,and decreased by 41 ℃ and 101 ℃ in the presence of CeO2 and MnOx,respectively.In situ DRIFTs showed that the reactive oxygen species on catalysts and NO-3 formed in the reaction process were the key factors for promoting soot oxidation in the presence of NO.The possible pathways were：gaseous O2 in the O2-rich condition was adsorbed onto the surface of catalysts at low temperature,thus abundant reactive oxygen species（such as O2-,O-2 and O-）were activated and transformed;the weakly adsorptive NO2 and reactive NO＊2 were oxidized into NO-3 ;NO-3 released reactive NO2＊ and O-at high temperture in turn,therefore enhancing soot oxidation with C（O） complex as intermediates.

关 键 词：碳烟氧化 MNOX CEO2 NO 

分 类 号：X51[环境科学与工程—环境工程] O643.3[理学—物理化学]