| 林俊敏,付名利,朱文波,叶代启.氧化碳烟的MnOx(0.4)-CeO2催化剂表面活性物种研究[J].分子催化,2014,(2):165-173 |
| 氧化碳烟的MnOx(0.4)-CeO2催化剂表面活性物种研究 |
| An Investigation of Surface Reactive Species on MnOx(0.4)-CeO2 Catalyst towards Soot Oxidation |
| 投稿时间：2013-12-26 修订日期：2014-02-15 |
| DOI： |
| 中文关键词: MnOx(0.4)-CeO2，碳烟氧化，催化，表面活性物种，机理 |
| 英文关键词:MnOx(0.4)-CeO2 soot oxidation catalysis surface reactive species mechanism |
| 基金项目:国家自然科学基金项目（面上项目，重点项目，重大项目） |
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| 中文摘要: |
| 采用柠檬酸络合燃烧法和共沉淀法制备了MnOx(0.4)-CeO2催化剂，用于模拟碳烟的燃烧.通过XRD、BET、Raman、H2-TPR、O2-TPD与XPS表征催化剂的结构和表面活性物种，并借助原位拉曼研究碳烟的催化剂氧化机理.结果表明柠檬酸络合燃烧法制备的MnOx(0.4)-CeO2-CA催化剂中有更多的Mn进入了CeO2的立方萤石结构，比表面积更大，氧空位、Mn4+和Ce4+更多，因而氧化还原性能更好，催化氧化碳烟的活性更高.O-在碳烟的氧化中起重要作用，Mn4+和Ce4+有利于氧化反应的进行，氧空位的增加能提高氧的吸附、迁移和转化能力，促进了碳烟的氧化.反应路径为O-溢出参与碳烟的氧化，同时产生氧空位，部分晶格氧O2-补充O-，气相氧不断吸附到氧空位上得到活化生成O2-，O2-转化为O-（可进一步转化为O2-），O-迁移至碳烟颗粒表面参与反应，生成CO2. |
| 英文摘要: |
| Citric acid complex method and coprecipitation method were utilized for the preparation of MnOx(0.4)-CeO2 catalysts towards model soot oxidation. The structure properties of and surface reactive species on the catalysts were characterized by XRD, BET, Raman, H2-TPR, O2-TPD and XPS. And the soot catalytic oxidation mechanism was investigated by in situ Raman spectra. The results showed that MnOx(0.4)-CeO2-CA catalyst synthesized with citric acid complex method, with more Mn ions incorporated into the ceria lattice, possessed larger specific surface area, more oxygen vacancies, Mn4+ and Ce4+. Thus, MnOx(0.4)-CeO2-CA exhibited better redox properties and higher soot oxidation activities. O- was found to play a key role in soot oxidation. Mn4+ and Ce4+ favored to the redox reaction, and the increase of oxygen vacancies were propitious to the adsorption, migration and transformation of oxygen species, boosting soot oxidation. The reaction path was O- spilled from the catalyst and reacted with soot firstly, oxygen vacancy was formed simultaneously, and then part of the lattice oxygen O2- replenish the consumed O-. Gaseous oxygen O2 adsorbed to the oxygen vacancy and activated to O2-, and then changed to O-(can transformed to O2- in the further step), O- migrated to the soot surface and oxidizes it very efficiently in the next cycle, CO2 was formed subsequently. |
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