| 摘要 |
<p>PURPOSE:To obtain a catalyst with excellent mechanical strength and oxidizing capacity of an exhaust gas by a method wherein a specific ratio of a heavy metal compound and an aggregate containing a rehydratable alumina is subjected to kneading or molding treatment to form an oxidizing catalyst having open pore ratio with a definite value and above and specific surface area. CONSTITUTION:As an oxidizing catalyst for purifying hydrocarbons, carbon monoxide and nitrogen monoxide within an exhaust gas, an aggregate containing 50wt% or more of a total amount consisting of 10-90wt% of a heavy metal compound such as iron or the like and 90-10wt% of a rehydratable alumina is subjected to the treatment preventing from being rehydrated and, after kneaded in the presence of water and molded, subjected to rehydrating treatment and, thereafter, baked at 1,000 deg.C or less. Thereby an oxidizing catalyst with a pore ratio of 20% or more and a specific surface area of 5m<2>/g or more having at least one hollow open pore is obtained. This catalyst has high mechanical strength and oxidizes an exhaust gas at a high ratio without reducing a catalytic capacity of the heavy metal compound.</p> |
