Mesoporous Ce_xMn_{1鈭?span style='font-style: italic'>x}O₂ composites as novel alternative carriers of supported Co₃O₄ catalysts for CO preferential oxidation in H₂ stream

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• 作者：Zhongkui Zhao ; ^{zkzhao@dlut.edu.cn} ; ^{zzkdlut@yahoo.com} ; Ronghua Jin ; Ting Bao ; Hongling Yang ; Xiaoli Lin ; Guiru Wang
• 关键词：CexMn1&minus ; xO2 composite ; Cobalt oxide loading ; CO selective oxidation ; H2O and CO2 tolerance ; Simulated syngas ; Hydrogen
• 刊名：International Journal of Hydrogen Energy
• 出版年：2012
• 期刊代码：42_03603199
• 类别：ch
• 出版时间：March, 2012
• 卷：37
• 期：6
• 页码：4774-4786
• 文件大小：2189 K

摘要

The mesoporous Co₃O₄ supported catalysts on Ce-M-O (M聽=聽Mn, Zr, Sn, Fe and Ti) composites were prepared by surfactant-assisted co-precipitation with subsequent incipient wetness impregnation (SACP-IWI) method. The catalysts were employed to eliminate trace CO from H₂-rich gases through CO preferential oxidation (CO PROX) reaction. Effects of M type in Ce-M-O support, atomic ratio of Ce/(Ce聽+聽Mn), Co₃O₄ loading and the presence of H₂O and CO₂ in feed were investigated. Among the studied Ce-M-O composites, the Ce-Mn-O is a superior carrier to the others for supported Co₃O₄ catalysts in CO PROX reaction. Co₃O₄/Ce_0.9Mn_0.1O₂ with 25聽wt.%loading exhibits excellent catalytic properties and the 100%CO conversion can be achieved at 125-200聽掳C. Even with 10 vol.%H₂O and 10 vol.%CO₂ in feed, the complete CO transformation can still be maintained at a wide temperature range of 190-225聽掳C. Characterization techniques containing N₂ adsorption/desorption, X-ray diffraction (XRD), H₂ temperature-programmed reduction (H₂-TPR) and scanning electron microscopy (SEM) were employed to reveal the relationship between the nature and catalytic performance of the developed catalysts. Results show that the specific surface area doesn鈥檛 obviously affect the catalytic performance of the supported cobalt catalysts, but the right M type in carrier with appropriate amount effectively improves the Co₃O₄ dispersibility and the redox behavior of the catalysts. The large reducible Co³⁺ amount and the high tolerance to reduction atmosphere resulted from the interfacial interaction between Co₃O₄ and Ce-Mn support may significantly contribute to the high catalytic performance for CO PROX reaction, even in the simulated syngas.