CERAMIC COATING FOR CATALYST CARRIER

摘要

PURPOSE: To provide a ceramic coating which has excellent adherence and remarkably low reactivity with sulfur compounds when used as a catalyst support for the treatment of an exhaust gas of a diesel engine. CONSTITUTION: A silica coating suitable for carrying dispersed catalyst particles is formed of a mixture consisting of two groups of the fine silica particles having respective average sizes and size ranges which are virtually non- overlapping. The particles of the first of the two groups have sufficient first average size sufficient to permit the particles of the first group (smaller group) to occupy voids between the particles of the second group (larger group) in a packed arrangement and the second group has a second average particle size which is at least 20 times greater than the first average particle size. Amorphous silica are preferred for use in forming a coating with improved adherence suitable for the treatment of diesel exhaust and are also useful to improve the adherence of coatings formed of other ceramic materials such as alumina, titania, zirconia and zeolite.