CO catalytic combustion over Co/Al2O3: Influence of diverse textural properties of alumina supports on the related oxidation activities

• Mesoporous aluminas were prepared by soft template and solvent evaporation methods.
• Much higher BET specific surface areas were achieved by mesoporous aluminas.
• Long distance ordered mesoporous structures were formed for the mesoporous aluminas.
• Co promoted mesoporous alumina of SE-700 gets the best CO oxidation activity.

A series of mesoporous aluminas were prepared by different synthesis procedures, including soft template (ST) and solvent evaporation (SE) methods, in various conditions. These mesoporous structures achieve significantly higher BET specific surface areas than the traditional one prepared by ceramic method (CE) (200–300 m2 g−1 vs 58 m2 g−1). A further loading of active cobalt component was subsequently conducted over different aluminas. The structures and reducibility of these materials were fully characterized by XRD, N2 adsorption–desorption, H2-TPR, TEM and XPS, correlating to their diverse evolutions of catalytic activity for CO oxidation. The best performance achieved over the sample SE-700 (SE method, 700 ̊C calcination), substantially attributing to its outstanding long distance ordered mesoporous structure of the alumina support, big pore channel, high surface CoOx content and the largest specific surface area. The catalyst ST-7.6 (ST method, pH = 7.6) showed a comparable activity, corresponding to its large pore size, the worm-like mesoporous structure and the absence of inactive CoAl2O4.

Figure optionsDownload high-quality image (284 K)Download as PowerPoint slide