NiNbO Catalyst Deposited on Anodized Aluminum Monoliths for the Oxidative Dehydrogenation of Ethane

Abstract

Aluminum monoliths were used as substrates to prepare structured catalysts. A rough alumina layer was generated on the surface of the substrates by anodizing followed by hydrothermal treatments. The dip-coating technique was used for coating the monolithic substrates. Aqueous suspensions with 0.15 and 0.30 g/g of Ni-Nb mixed oxides catalysts were prepared for that purpose. Colloidal SiO2 was added as a binder in order to obtain homogeneous and adherent coatings. The samples were characterized by SEM, TPR, XPS, XRD, and N2 adsorption and tested in the oxidative dehydrogenation (ODH) of ethane to ethylene. The silica particles produced a drop in catalytic activity without affecting ethylene selectivity. The former effect was attributed mainly to a decrease in surface nickel concentration and an increase in reduction temperature. The presence of anodized aluminum substrates in the reaction environment did not have a significant influence on catalytic activity and product distribution, as observed for the coated monoliths used in this work, thus being a useful material to prepare structured catalysts for low-temperature ethane ODH.