the present invention provides a multilayer mounting mat for mounting a pollution control element . the mounting mat comprises a layer of intumescent material between two non - intumescent layers defining opposite major sides of the mounting mat . the mounting mat in accordance with the present invention is suitable for mounting a pollution control element in a pollution control device and is in particular suitable for mounting fragile monolith such as thin - wall and ultra thin - wall monoliths . also , the mounting mats conveniently exhibit a good or excellent holding pressure over a wide temperature range and can be formulated in an inexpensive way . the invention also provides a pollution control device comprising a pollution control element arranged in a casing with the mounting mat disposed between the casing and pollution control element .