Preparation of structured egg-shell catalysts for selective oxidations by the ANOF technique

Shell-type catalysts supported on metal wires were prepared by anodic oxidation with spark discharge (the "ANOF" technique) in the presence of precursors of the catalytically active phase. Aluminium, magnesium and titanium oxide were employed as carriers, whereas nickel (also doped with lithium), chromium or molybdenum were the active components. The carrier oxides displayed regular pore structures determined by the preparation condition and influenced by the precursor of the active component, which was incorporated in the pore system of the carrier during the anodisation process. The nickel-containing catalysts were found to yield 60-90% cyclohexene selectivity in the oxidation of cyclohexane. (C) 2001 Elsevier Science B.V. All rights reserved.