催化学报 ›› 2013, Vol. 34 ›› Issue (2): 283-293.DOI: 10.1016/S1872-2067(11)60484-1

• 研究论文 • 上一篇    下一篇

焙烧与预处理条件对 Co3O4 催化氧化 CO 性能的影响

余运波a,*, 赵娇娇a, 韩雪a, 张燕a, 秦秀波b, 王宝义b   

  1. a中国科学院生态环境研究中心, 北京 100085; b中国科学院高能物理研究所, 核分析技术重点实验室, 北京 100049
  • 收稿日期:2012-09-20 修回日期:2012-11-10 出版日期:2013-02-05 发布日期:2013-02-05

Influence of calcination and pretreatment conditions on the activity of Co3O4 for CO oxidation

YU Yunbo a,*, ZHAO Jiaojiao a, HAN Xue a, ZHANG Yan a, QIN Xiubo b, WANG Baoyi b   

  1. a Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; b Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
  • Received:2012-09-20 Revised:2012-11-10 Online:2013-02-05 Published:2013-02-05

摘要: 采用沉淀法制备了 Co3O4, 考察了焙烧和预处理条件对其结构、低温催化氧化 CO 性能的影响. 热重分析表明, 未经焙烧的样品以 Co(OH)2CO3 的形式存在, 150~400 oC 空气气氛中焙烧后, 样品以立方相 Co3O4 的形式存在. N2 吸附-脱附法、X 射线衍射、透射电镜及活性测试结果表明, 以纳米颗粒物存在的 Co3O4 的比表面积、颗粒尺寸、催化氧化 CO 活性与焙烧温度密切相关. 正电子湮没寿命谱、O2-程序升温脱附与定温条件下 CO 氧化测试结果表明, 合适温度 (150~250 oC) 下 N2 预处理有利于 Co3O4 表面氧空穴团的形成, 它在吸附活化分子氧以及 CO 催化氧化反应中起到关键作用. 同时讨论了预处理作用下Co3O4表面氧空穴的再构机制.

关键词: 四氧化三钴, 焙烧, 预处理, 氧空穴, 一氧化碳氧化

Abstract: The influence of calcination and pretreatment conditions on the structure of Co3O4 and its activity for CO oxidation were studied. TG analysis indicated that the precursor of Co3O4 prepared by a precipitation method was present in the form of cobalt hydroxide carbonate, calcination of which within the temperature range of 150–400 oC in air resulted in the formation of cubic phase Co3O4. N2 adsorption-desorption, powder X-ray diffraction, transmission electron microscopy, and activity test results showed that the prepared Co3O4 samples were comprised of nanoparticles, with the specific surface area and size distribution closely related to the calcination temperature. Over these samples, a size dependence of the catalytic activity for CO oxidation was clearly observed. As identified by positron annihilation lifetime spectrum, low temperature oxygen temperature-programmed desorption, and durability testing for CO oxidation, pretreatment of Co3O4 in N2 within the temperature range 150–250 oC favors the formation of surface oxygen vacancy clusters, the occurrence of which would be beneficial for the adsorption and activation of O2, and also for the catalytic oxidation of CO. Meanwhile, the reconstruction of oxygen vacancies on the surface of Co3O4, induced by the pretreatment process, was also discussed.

Key words: Tricobalt tetraoxide, Calcination, Pretreatment, Oxygen vacancy, Carbon monoxide oxidation