| 摘要 |
PURPOSE:To display catalytic activity over a wide temp. range in the catalytic reduction of NOx as regards a catalyst having Pt and Sn supported on the carrier having a high specific surface area by a method wherein Pt and Sn are supported thereon within a specific range of ratio and the atomic ratio of Sn to Pt is given within a predetermined range. CONSTITUTION:The catalyst having Pt and Sn supported simultaneously on the carrier with a high specific surface area accelerates a selective reduction of hydrocarbons by NOx in an atmosphere of excessice oxygen. In particular, if the atomic ratio of Pt to Sn is changed, the active temp. range of Pt and Sn catalyst is shifted toward high temp. side. More specifically, 0.01-5wt.% Pt and 0.01-10wt.% Sn are supported on the carrier and the atomic ratio of Sn to Pt is given within the range of 0.1-2, whereby the active temp. of the Pt-Sn catalyst can be set within a desired range. |
