Ceramic wash-coat for catalyst support

摘要

A wash-coat ( 16 ) for use as a support for an active catalyst species ( 18 ) and a catalytic combustor component ( 10 ) incorporating such wash-coat. The wash-coat is a solid solution of alumina or alumina-based material (Al₂O₃-0-3 wt % La₂O₃) and a further oxide exhibiting a coefficient of thermal expansion that is lower than that exhibited by alumina. The further oxide may be silicon dioxide (2-30 wt % SiO₂), zirconia silicate (2-30 wt % ZrSiO₄), neodymium oxide (0-4 wt %), titania (Al₂O₃-3-40% TiO₂) or alumina-based magnesium aluminate spinel (Al₂O₃-25 wt % MgO) in various embodiments. The active catalyst species may be palladium and a second metal in a concentration of 10-50% of the concentration of the palladium.