Each monolith contains thousands of parallel channels or holes, which are defined by many thin walls, in a honeycomb structure. The channels can be square, hexagonal, round, or other shapes. The hole density may be from 30 to 200 per cm2, and the separating walls can be 0.05 to 0.3 mm. The many small holes have a much larger surface area than one large hole. High surface area facilitates catalytic reaction or filtration. The open spaces in the cross-sectional area are 72 to 87% of the frontal area, so resistance to the flow of gases through the holes is low, which minimizes energy consumed forcing gases through the structure.
The monolith is a substrate that supports a catalyst. After the monolith is complete, a washcoat is applied that deposits oxides and catalyst(s) (most commonly platinum, palladium, and/or rhodium) on the walls of the holes.
Alternative structures include corrugated metal and a packed bed of coated pellets or other shapes.
monolith, catalyst, support, monolithic, catalyst, supports, extruded, structures, that, core, many, catalytic, converters, most, diesel, particulate, filters, some, catalytic, reactors, most, catalytic, converters, used, vehicle, emissions, control, stationar. Monolithic catalyst supports are extruded structures that are the core of many catalytic converters 1 most diesel particulate filters and some catalytic reactors Most catalytic converters are used for vehicle emissions control Stationary catalytic converters can reduce air pollution from fossil fuel power stations Properties edit nbsp Diesel soot catalytic reduction device SCR made of silicon carbide monolithsMonoliths for automotive catalytic converters are made of a ceramic that contains a large proportion of synthetic cordierite 2MgO 2Al2O3 5SiO2 which has a low coefficient of thermal expansion 1 Each monolith contains thousands of parallel channels or holes which are defined by many thin walls in a honeycomb structure The channels can be square hexagonal round or other shapes The hole density may be from 30 to 200 per cm2 and the separating walls can be 0 05 to 0 3 mm The many small holes have a much larger surface area than one large hole High surface area facilitates catalytic reaction or filtration The open spaces in the cross sectional area are 72 to 87 of the frontal area so resistance to the flow of gases through the holes is low which minimizes energy consumed forcing gases through the structure The monolith is a substrate that supports a catalyst After the monolith is complete a washcoat is applied that deposits oxides and catalyst s most commonly platinum palladium and or rhodium on the walls of the holes Alternative structures include corrugated metal and a packed bed of coated pellets or other shapes Uses editDiesel particulate filters DPF Catalytic incineration Catalyst support for chemical processes Vehicle emissions controlReferences edit a b Williams J Monolithic structures materials properties and uses Catalysis Today 69 2001 3 9 nbsp This catalysis article is a stub You can help Wikipedia by expanding it vte Retrieved from https en wikipedia org w index php title Monolith catalyst support amp oldid 1165993146, wikipedia, wiki, book, books, library,
