催化学报

催化学报 ›› 2010, Vol. 31 ›› Issue (11): 1335-1341.DOI: 10.1016/S1872-2067(10)60122-2

• 研究论文 • 上一篇    下一篇

57Fe 穆斯堡尔谱研究 Ir-Fe 催化剂用于 CO 选择氧化反应

刘阔 1,2, 张万生 1, 王军虎 1 , 王爱琴 1, 黄延强 1, 金长子 1, 沈俭一 3, 张涛 1   

  1. 1中国科学院大连化学物理研究所催化基础国家重点实验室, 辽宁大连 116023; 2中国科学院研究生院, 北京 100049; 3南京大学化学化工学院, 江苏南京 210093
  • 收稿日期:2010-05-12 出版日期:2010-11-12 发布日期:2014-03-28

57Fe Mössbauer Spectroscopy of Ir-Fe Catalysts for Preferential CO Oxidation in H2

LIU Kuo1,2, ZHANG Wansheng1, WANG Junhu1, WANG Aiqin1, HUANG Yanqiang1, JIN Changzi1, SHEN Jianyi3,#, ZHANG Tao1,*   

  1. 1State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, Liaoning, China; 2Graduate University of Chinese Academy of Sciences, Beijing 100049, China; 3Department of Chemistry, Nanjing University, Nanjing 210093, Jiangsu, China
  • Received:2010-05-12 Online:2010-11-12 Published:2014-03-28

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摘要： 采用不同浸渍顺序制备了三种 Ir-Fe 催化剂, 其 CO 选择氧化 (PROX) 反应活性差别很大, 其中共浸渍的 Ir-Fe 催化剂活性最高. 吸附量热研究表明, 三种催化剂的 H2 和 CO 吸附存在差别. 通过对三种催化剂还原后、再氧化和反应后准原位 57Fe 穆斯堡尔谱的研究, 得到各种 Fe 物种信息. 结果表明, 三种制备方法影响催化剂中 Ir-Fe 相互作用强度, 导致催化剂中 Fe 物种的氧化还原性能不同. 催化剂中 Fe2+(a) 的含量与 CO 转化率呈正比关系, Fe2+(a) 是 PROX 反应过程中活化氧的活性中心. 浸渍顺序改变了 Ir-Fe 间相互作用强度, 从而改变 Fe2+(a) 物种含量, 影响 PROX 反应活性. Ir-Fe 间的相互作用可以稳定活化氧的 Fe2+(a) 物种, 为今后研究金属-金属间的相互作用提供借鉴.

关键词: 一氧化碳, 选择氧化, 铱, 铁, 准原位穆斯堡尔谱, 吸附量热, 金属-金属相互作用

Abstract: New insights on the interaction between Ir and Fe oxide are reported. Three Ir-Fe catalysts were prepared by different impregnation sequences of an Al2O3 support. Co-impregnation gave a better catalyst for the preferential CO oxidation in H2 (PROX) reaction. Microcalorimetry data showed that the adsorption of CO and H2 were different. Quasi in situ Mössbauer data of the three catalysts after reduction, reoxidation, and PROX reaction showed that a strong interaction between Ir and Fe affected the redox properties of the Ir-Fe catalysts. CO conversion was proportional to the concentration of the Fe2+(a) species, thus, Fe2+(a) was an active site in the PROX reaction. The impregnation sequence influenced the interaction between Ir and Fe and consequently, the amount of the active Fe2+(a) species. A strong Ir-Fe interaction stabilized the active Fe2+ sites for activating O2.

Key words: carbon monoxide, selective oxidation, iridium, iron, quasi Mössbauer spectroscopy, microcalorimetry, metal-metal interaction