Catalytic combustion of propane over mixed oxides derived from Cu xMg 3-xAl hydrotalcites

Cu-based mixed oxides (Cu xMg 3-xAlO-800s, x = 0, 0.5, 1.0, 1.5, 2.0 and 3.0) were prepared by calcinations of corresponding Cu xMg 3-xAl ternary hydrotalcites (Cu xMg 3-xAl-HTLCs) at 800°C and used for catalytic combustion of propane. The Cu xMg 3-xAl ternary hydrotalcites and derivedcombustion catalysts were well characterized to investigate the dependence of the performance of propane catalytic combustion with their structure and components. The results showed that Cu can replace Mg in a wide range of Cu/Mg ratios to form Cu xMg 3-xAl-HTLCs with the unique layered structure of hydrotalcite, though the Cu substitution significantly deteriorates the thermal stability of the Cu xMg 3-xAl-HTLCs. It was found that calcinations at 800°C completely transformed the Cu xMg 3-xAl-HTLCs to Cu xMg 3-xAlO-800 mixed oxides, containing spinel, periclase and tenoriteoxide phases. The TPR results revealed those catalysts derived from hydrotalcites were easier to be reduced than the simply mixed oxides, this was due to the strong interactions among the components existing in the Cu xMg 3-xAlO-800 materials. The Cu xMg 3-xAlO-800 catalysts exhibit superiorcatalytic activity in propane combustion to Pd/Al 2O 3 and the mechanically mixed oxides. The excellent activities of the Cu xMg 3-xAlO-800 were attributed to the strong interaction among the component oxides as observed by the XRD, TG-DSC and TPR characterizations. © 2012 Elsevier Ltd. All rights reserved.