高等学校化学学报 ›› 2019, Vol. 40 ›› Issue (8): 1670-1678.doi: 10.7503/cjcu20190161

• 物理化学 • 上一篇    下一篇

K促进的纳米片状水滑石衍生CoAlO金属氧化物催化碳烟燃烧

任伟, 田野, 邢令利, 杨岳溪, 丁彤, 李新刚   

  1. 天津化学化工协同创新中心, 天津市应用催化科学与工程重点实验室, 天津大学化工学院, 天津 300354
  • 收稿日期:2019-03-18 修回日期:2019-06-01 出版日期:2019-08-10 发布日期:2019-08-02
  • 通讯作者: 李新刚,男,博士,教授,博士生导师,主要从事环境催化方面的研究.E-mail:xingang_li@tju.edu.cn E-mail:xingang_li@tju.edu.cn
  • 基金资助:
    国家自然科学基金(批准号:21878213)和高等学校学科创新引智计划(批准号:B06006)资助.

K Promoted Nanosheets-like Hydrotalcite-derived CoAlO Metal Oxides for Catalytic Soot Combustion

REN Wei, TIAN Ye, XING Lingli, YANG Yuexi, DING Tong, LI Xingang   

  1. Collaborative Innovation Center of Chemical Science and Engineering(Tianjin), Tianjin Key Laboratory of Applied Catalysis Science and Engineering, School of Chemical Engineering & Technology, Tianjin University, Tianjin 300354, China
  • Received:2019-03-18 Revised:2019-06-01 Online:2019-08-10 Published:2019-08-02
  • Supported by:
    Supported by the National Natural Science Foundation of China(No.21878213) and the Program for Introducing Talents of Discipline to Universities of China(No.B06006).

摘要: 采用水热法合成了负载K的纳米片状水滑石衍生CoAlO金属氧化物,其表现出优异的催化碳烟燃烧活性.氢气-程序升温还原(H2-TPR)实验结果表明,K与Co之间的相互作用提高了催化剂的氧化还原性能.X射线光电子能谱(XPS)分析结果表明,K的负载增大了表面Co2+/Co3+的比例,促进了氧空位的产生,提高了催化剂对气相氧的吸附能力.碳烟-程序升温还原(Soot-TPR)实验结果表明,K的负载增加了表面吸附氧数量.动力学实验结果表明,K的负载增加了单位质量催化剂上的活性氧数量、反应速率和转化频率(TOF),从而提高了催化剂的本征活性.另外,碳烟颗粒可以分散在纳米片的层间,与活性位点的接触效率得到提高,也有利于提高催化碳烟燃烧活性.

关键词: 水滑石衍生金属氧化物, K与Co相互作用, 氧空位, 碳烟燃烧, 纳米片形貌

Abstract: We synthesize the K supported nanosheets-like hydrotalcite-derived CoAlO metal oxide by a facile hydrothermal method, which exhibits the superior catalytic performance for soot combustion. The H2-TPR results show that the interaction between K and Co leads to the improved redox ability of 5K/CoAlO. The Co2p XPS results show that the Co2+/Co3+ ratios get increased after loading K on the CoAlO support. It demonstrates that the K loading promotes the transition of cobalt species from Co3+ to Co2+, which leads to the generation of oxygen vacancies. The O1s XPS results show that the Oads/(Oads + Olat) ratio increases after K loading. The soot-TPR results indicate that the interaction between K and Co contributes to the adsorption of gaseous O2 remarkably. During kinetic experiments, 5K/CoAlO exhibits the high reaction rate per unit mass of catalyst, active oxygen(O*) amount per unit mass of catalyst and TOF, which demonstrates that the interaction between K and Co improves the intrinsic activities of 5K/CoAlO. In addition, owing to the nanosheets-like morphology of 5K/CoAlO, the soot particulates could be highly dispersed on the nanosheets-like layers of 5K/CoAlO and get more access to active components, which is favorable to soot combustion. In summary, the improved amount of active oxygen species and the increased soot-catalyst contact efficiency guarantee the high soot combustion activity of our K supported CoAlO catalysts. Our work provides a novel approach to designing a highly efficient Co-based hydrotalcite-derived oxides catalyst for catalytic soot combustion.

Key words: Hydrotalcite-derived metal oxide, Interaction between K and Co, Oxygen vacancy, Soot combustion, Nanosheets-like morphology

中图分类号: