Chinese Journal of Catalysis

Chinese Journal of Catalysis ›› 2010, Vol. 31 ›› Issue (11): 1335-1341.DOI: 10.1016/S1872-2067(10)60122-2

• Research papers • Previous Articles     Next Articles

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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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