Aluminum wire meshes coated with Co-Mn-Al and Co oxides as catalysts for deep ethanol oxidation

Abstract

Aluminum meshes with different wire diameter and open space area were anodized in H2SO4 solution and then treated under hydrothermal conditions in aqueous solution of Co and Mn nitrates; the layered double hydroxide precursors formed on the supports surface were transformed into Co-Mn-Al mixed oxides after heating. For comparison, aluminum mesh coated with Co3O4 oxide was also prepared. Properties of the supported catalysts were characterized by XRD, SEM, TPR, and Raman spectroscopy and examined in deep ethanol oxidation. It was found that activity of the catalysts depended on the amount of active components deposited on the supporting mesh. Comparison of specific activities (calculated as amount of ethanol converted per unit weight of active oxides) at the same space velocity demonstrated the size of mixed oxides particles as the important parameter for oxidation activity: decreasing in particle size led to increased catalysts efficiency. The Co3O4 oxide deposited from Co(OH)2 suspension provided more active catalyst than Co-Mn-Al mixed oxides obtained by long-term hydrothermal treatment of the anodized aluminum meshes followed by heating.