Preparation and Application of Catalysts for Zero Air Generators

Using pseudoboehmite and cerium nitrate as raw materials, a cerium dioxide-doped alumina support was prepared by the hot oil column method. Subsequently, with platinum nitrate and palladium nitrate solutions as precursor salts, the active components were loaded onto the supports via the incipient wetness impregnation, followed by an activation treatment, thus obtaining platinum-palladium bimetallic catalysts for hydrocarbon elimination in zero-air generators. The catalyst was characterized by XRD, BET, SEM, TEM, XPS, and Raman spectroscopy. The results showed that the as-prepared supports possess a large specific surface area, and the noble metals Pt and Pd are uniformly distributed on the support surface. After activation treatment, the structural stability and catalytic reaction activity of the catalysts are significantly enhanced. Performance tests simulating the actual operating conditions of zero-air generators show that the catalysts exhibit excellent hydrocarbon elimination capability: when the inlet methane concentration is 50 ppm, the outlet methane content can be reduced to below 10 ppb. Moreover, no obvious attenuation of catalyst activity is observed after a 1000-h long-term stability test, which meets the practical application requirements of zero-air generators.