氧化反应温度对柴油机颗粒物表面官能团演变的影响  

Impact of Oxidation Reaction Temperature on Surface Functional Groups Transformation of Diesel Particles

作　　者：俞瑶[1] 吕刚[1] 宋崇林[1] 宋金瓯[1] 郝斌[1] 李博[1] 孙宏科[1] 

机构地区：[1]天津大学内燃机燃烧学国家重点实验室,天津300072

出　　处：《燃烧科学与技术》2016年第1期37-44,共8页Journal of Combustion Science and Technology

基　　金：国家重点基础研究发展计划(973计划)资助项目(2013CB228502);国家自然科学基金资助项目(51476115)

摘　　要：采用原位红外光谱仪并结合热重分析仪和程序升温氧化-质谱联用仪的测量结果对国Ⅳ柴油机颗粒物表面官能团在颗粒物氧化反应过程中的演变规律进行半定量分析.结果表明,起燃温度（450,℃）前,随反应温度升高,柴油机颗粒物表面碳氢官能团迅速减少、碳氧官能团不断生成,而从程序升温氧化反应曲线可以看到反应气氛中的O2通过化学吸附参与表面官能团的转化,这和碳氧官能团增加的规律相一致;反应温度超过450,℃时,随温度升高,碳氧表面官能团减少,颗粒物氧化燃烧,两个反应具有同步性;在50~425,℃范围内,氧化反应温度对微粒中脂肪烃的支链化程度影响不大;反应温度低于450,℃时,在绝大多数温度段,C=O结构相对含量与C—O结构相对含量的变化趋势相反,表明低温氧化反应中两类官能团间存在相互转化.The semi-quantitative analysis of the surface functional group transformation process of state Ⅳ standard diesel particles was implemented based on in-situ DRIFTS and the results from TGA（thermogravimetric analysis）and TPO-MS（temperature program oxidation-mass spectrometer）.The analysis reveals the noticeable decrease in hydrocarbon functional groups and the continuous generation of oxygenic functional groups with the increase of temperature up to the light-off value（450,℃）.It can also be observed from the TPO curves that oxygen participates in the above functional group transformations by chemical adsorption.This adsorption agrees with the increase of the relative content of oxygenic functional groups.When the temperature further increases from 450,℃,a decrease in the oxygenic functional groups and the rapid oxidative combustion of diesel particles are simultaneously observed through in-situ DRIFTS. With the temperature range of 50—425,℃,the oxidation temperature has no significant impact on the branched degree of fatty hydrocarbons on diesel particles.Meanwhile the relative amount of C=O and C—O structures exhibits opposite variation trends in most cases below 450,℃,indicating the mutual transformation between these two oxygenic structures.

关 键 词：柴油机颗粒物 表面官能团 漫反射傅里叶变换红外光谱 氧化活性 

分 类 号：TF055[冶金工程—冶金物理化学]