Mechanical stability of monolithic catalysts: Improving washcoat adhesion by FeCrAl alloy substrate treatment

Alumina-washcoated FeCrAl alloy sheets are prepared to investigate the effects of metallic substrate pretreatments on the mechanical stability of monolithic catalysts. It is shown that chemical and thermal pretreatments produce different effects on the metallic surface morphology and phase, and different mechanisms are involved in their ways of improving the washcoat adhesion. Combination of chemical and thermal pretreatments leads to the formation of alpha-alumina whiskers on corroded and rough metallic surface, thus giving the most satisfactory washcoat adhesion. It is also pointed out that not only mechanical shock resistance but also thermal shock resistance is crucial to metallic monolithic catalysts. (C) 2017 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.