Monolithic materials have been widely used for over 20 years as catalyst supports in the abatement of emissions fTom mobile and stationary sources. They have been most successfully used for applications where high volmnetric flow rates and potential for thermal shock are required. Their use is expected to further increase as new applications are found. o This paper describes three new catalytic technologies which require a monolithic support; 1) the diesel oxidation catalyst commercialized in 1994 and 2) NOn abatement with hydrocarbons in lean environments and 3) catalytically supported thermal combustion both of which are currently under development.