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采用等量分步浸渍法先后将Ｃｏ与贵金属组份浸于ＣｅＯ２上，经５００℃焙烧２ｈ，４５０℃氢气还原１ｈ制得Ｃｏ－Ｐｔ／ＣｅＯ２和Ｃｏ－Ｒｈ／ＣｅＯ２催化剂。活性测试结果表明，贵金属与Ｃｏ之间具有催化协同效应。对ＣＯ氧化，Ｐｔ与Ｃｏ的协同效应较显著，而对富氧条件下ＣＨ４选择还原ＮＯ，Ｒｈ与Ｃｏ的协同效应更为明显。ＸＰＳ和ＥＸＡＦＳ结果一致表明，经Ｈ２还原后，样品Ｃｏ／ＣｅＯ２、Ｃｏ－Ｐｔ／ＣｅＯ２和Ｃｏ－Ｒｈ／ＣｅＯ２中Ｃｏ均以高分散的金属钴形式存在，ＸＲＤ已难以检测。此外，样品表面Ｃｏ原子百分数的提高及Ｃｏ－Ｃｏ壳层配位数的下降均表明，微量Ｐｔ或Ｒｈ的加入进一步提高了金属Ｃｏ的分散性。对微量Ｐｔ和Ｒｈ在Ｃｏ／ＣｅＯ２中的作用作了一些探讨。
The Co-Pt / CeO2 and Co-Rh / CeO2 catalysts were prepared by impregnating Co and precious metal components on CeO2 by the same amount of stepwise impregnation method, followed by calcination at 500 ℃ for 2h and hydrogen reduction at 450 ℃ for 1h. The activity test results show that there is a catalytic synergistic effect between the noble metal and Co. The synergistic effect of Pt and Co on CO oxidation is significant, while the synergistic effect of selective reduction of NO, Rh and Co on CH4 under oxygen-rich conditions is more obvious. The results of XPS and EXAFS show that after H2 reduction, Co in Co / CeO2, Co-Pt / CeO2 and Co-Rh / CeO2 are all in the form of highly dispersed metallic cobalt, which has been difficult to detect by XRD. In addition, both the increase of the Co atom percentage and the decrease of the Co-Co shell coordination number on the sample surface show that the addition of trace Pt or Rh further improves the dispersibility of the metal Co. The effect of trace Pt and Rh in Co / CeO2 was discussed.