(582c) Low Temperature Carbon Monoxide Oxidation Using Microfibrous Entrapped Catalyst

A nano-dispersed precious metal catalyst entrapped in the metal micro-fibers is developed for ambient temperature CO oxidation in the presence of moisture. This novel catalyst comprises a precious metal, a metal oxide on an inert support such as silica or alumina. The catalyst is prepared by incipient wetness impregnation. The catalyst yielded a steady CO conversion (>95%) in the presence of moisture (RH 10-90%) for more than 8 hours at ambient temperature (23 C). The catalyst was evaluated at various face velocities, CO challenge concentrations at ambient temperature with RH of 10-90%. The catalyst demonstrated an extremely high activity for CO oxidation. In a thin bed test, a challenge gas (RH 50%) containing 250 ppmv CO was passed through a packed bed of the catalyst particles (200 µm) with a bed thickness of 2 mm at a gas face velocity of 30 cm/s. The catalyst successfully reduced the CO concentration to below 20 ppmv for 8 hours without any deactivation.

The performance of the catalyst is significantly improved after entrapping into metal microfibers. Microfibrous entrapment substantially reduced the bed thickness and pressure drop over the bed, for achieving the same CO conversion. Therefore, this novel catalyst composition entrapped in a microfibrous media can effectively be used in a fire escape mask to provide the wearer protection against CO resulting from fire or explosions. Additionally, it can also be used as a catalytic filter for cathode air in the PEMFC systems.