| 摘要 |
PURPOSE:To obtain the catalyst capable of excellently cleaning NOX at a low temp. of a exhaust gas and a lean air-to-fuel ratio by controlling the specific surface of gamma-alumina contained in the catalyst to >=300m<2>/g and incorporating a part of the metallic active species into the gamma-alumina lattice in a dispersed and combined state. CONSTITUTION:The gamma-alumina catalyst obtained by the sol-gel method has >=300m<2>/g specific surface. At least a part of the metallic active species are incorporated into the gamma-alumina lattice in a dispersed and combined state. The species are previously added into a polymer-aluminum gel before the gamma-alumina is formed, hence the species form gamma-alumina based on the dissociation of the thermally decomposed polymer, and the species are uniformly dispersed into the gamma-alumina latticed molecule and combined. The polymer is dissociated in the air, in an inert gas atmosphere or in vacuum to avoid sintering. |
