| 摘要 |
PURPOSE:To stably maintain decomposing and removing functions for a long duration by reproducing an NOx decomposition activity of a specified NOx decomposition catalyst by bringing the catalyst into contact with a reducing agent in the case that the NOx decomposition activity of the catalyst is lowered. CONSTITUTION:This NOx decomposition catalyst is so formed as to have the distribution maxima of fine pore diameters at 50-100Angstrom and 500-1000Angstrom and is composed of a porous support consisting of either one or a plurality of gamma-alumina, zirconia, and titanium oxide and either one or a plurality of iridium, platinum, and rhodium carried on the porous support. A combustion discharge gas is processed at an NOx removing part and as the reaction proceeds, the function of the NOx decomposition catalyst A is lowered. This state is detected by an NOx sensor 9 and hydrogen gas g2 is supplied to the NOx decomposition catalyst A from a hydrogen storage part 8. As a result, the NOx decomposition function of the NOx decomposition catalyst A is reproduced and the catalyst exhibits high removal function again. |
