MnO_x modified Co₃O₄-CeO₂ catalysts for the preferential oxidation of CO in H₂-rich gases

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• 作者：Qiang Guo ; Yuan Liu
• 关键词：MnO_x ; Co₃O₄ ; CeO₂ ; Preferential oxidation ; CO ; Hydrogen
• 刊名：Applied Catalysis B ; Environmental
• 出版年：2008
• 期刊代码：4_09263373
• 类别：ce
• 出版时间：16 July 2008
• 卷：82
• 期：1-2
• 页码：19-26
• 文件大小：897 K

摘要

In this work, MnO_x modified Co₃O₄-CeO₂ catalysts were prepared and used for preferential oxidation of CO in hydrogen-rich gases. The catalytic performance tests results showed that the catalyst with Co:Ce:Mn molar ratio of 8:1:1 exhibited the best low-temperature CO oxidation activity and higher selectivity for CO-PROX reaction among tested catalysts. 100%CO conversion could be obtained over this catalyst at 80–180 °C with the feeding gas of 1 vol.%CO, 1 vol.%O₂, 50 vol.%H₂ and N₂ balance under the space velocity of com/cache/MiamiImageURL/B6TF6-4RM7MWH-2-V/0?wchp=dGLbVtz-zSkWz" alt="View the MathML source" title="View the MathML source" align="absbottom" border="0" height=19 width="120"/>. Adding CO₂ and/or water was unfavorable for CO removal, even so complete oxidation of CO was still achieved over this catalyst with the reaction stream of 20 vol.%CO₂, 10 vol.%H₂O, 1 vol.%CO, 1 vol.%O₂, 50 vol.%H₂ and N₂ balance under high space velocity of com/cache/MiamiImageURL/B6TF6-4RM7MWH-2-W/0?wchp=dGLbVtz-zSkWz" alt="View the MathML source" title="View the MathML source" align="absbottom" border="0" height=19 width="119"/> at reaction temperature range of 160–180 °C. The catalysts were characterized by XRD, TEM, EDX, TPR and XPS techniques and the results showed that adding MnO_x into Co₃O₄-CeO₂ led to more uniform mixing of Co₃O₄ and CeO₂ particles and led to finely dispersed and high valence state cobalt oxides species, which contributed to high catalytic activity of Co-Ce-Mn mixed oxides catalysts.