Integrity of Alumina Catalytic Support Prepared by Anodization in a High Temperature Steam Environment

Abstract

As a catalytic support for passive autocatalytic recombiner in nuclear power plants, anodic alumina layer was formed on stainless steel 304 by applying either Al or NiAl diffusion coatings on 304SS, followed by anodization and calcination. The anodic alumina had porous and nano-fibrous morphology and showed comparable hydrogen conversion ratio as the conventional wash-coated catalytic support. Integrity of catalytic supports was evaluated by steam oxidation test at 900 °C for 100 h. The wash-coated catalytic support exhibited oxide breakaway and Fe-oxide formation. On the other hand, α-alumina was formed on anodized catalytic support with Al or NiAl diffusion layers, which showed good adherence to the underlying metal substrate.