Abstract
Catalytic activity of the Co-Mn-Mg-Al mixed oxide spinel catalysts was examined in CO oxidation by O-2. The prepared catalysts were characterized by chemical analysis (ICP), infrared spectroscopy (FTIR), thermal analysis (TG, DTG), powder X-ray diffraction (XRD), surface area measurements, and scanning electron microscopy (SEM). The calcined hydrotalcite-like precursor was composed of spinel-like Co-Mn-Mg-Al mixed oxide as the only XRD crystalline phases. The nanosized spinel oxide catalysts produced by calcination of hydrotalcites showed higher SBET than CoMn-hydrotalcite samples as calcination led to dehydroxylation and carbonate decomposition of anions in interlayer spaces. All the catalysts showed 100% CO conversion at high temperature even those calcined at 800 degrees C. A catalyst with Co/Mn = 4 and calcined at 500 degrees C showed 100% CO conversion at 160 degrees C. Moreover, this catalyst exhibited quite good durability without deactivation in 60 h stability test. (C) 2009 Elsevier B.V. All rights reserved.