Fabrication of an aerogel composite catalytic converter

The purpose of this project was to contribute to the development of aerogel-based automotive catalytic converters. Existing catalytic converters utilize platinum and palladium catalysts to oxidize the carbon monoxide and unburned hydrocarbons in automotive exhaust. However, these noble metals are expensive and environmentally damaging to produce. Aerogels consist of a nanoscale solid lattice surrounded by air. Because of their high surface areas, metal oxide aerogels can catalyze the oxidation of carbon monoxide and hydrocarbons without the use of noble metals. We utilized epoxide proton-scavenging recipes to create alumina and chromia sol gels and xerogels. An alumina epoxide recipe was also combined with Union’s Rapid Supercritical Extraction process in order to fabricate alumina aerogels from non-alkoxide precursors. The aerogels’ surface area was only 171m2/g, considerably lower than the 470m2/g measured for alumina xerogels prepared from the same epoxide recipe. Both materials displayed a highly porous microstructure when imaged with a scanning electron microscope. In addition, a catalytic testing system was designed to measure the aerogels’ and xerogels’ ability to catalyze the oxidation of carbon monoxide and propane. The designed system heats simulated automobile exhaust to temperatures up to 500°C, flows the exhaust through a stainless steel reactor containing the catalytic sample, and determines the composition of the exhaust exiting the reactor using a four gas infrared analyzer. Preliminary testing of the assembled system demonstrated that it is unlikely to leak poisonous CO during testing but can only heat air to a temperature of 300°C in its current configuration.

Union College Schaffer Library Digital Projects

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