| 摘要 |
PROBLEM TO BE SOLVED: To provide a material capable of temporarily occluding NOx in oxygen-rich exhaust gas from a diesel engine, etc., or capable of occluding and removing NOx discharged into the air and to obtain a device for treating NOx with the material. SOLUTION: This material is a hollandite type multiple oxide using K as an alkali metal, contg. Al and Sn as principal metallic elements and represented by K1.8 Al1.8 Sn6.2 O12 . The multiple oxide is obtd. by slowly dropping an aq. soln. of aluminum nitrate and potassium nitrate in a soln. of tetraisopropoxy tin in isopropanol, successively bringing them into hydrolysis, evaporation to dryness at 100 deg.C and pulverization with an alumina mortar and heat-treating the resultant stock compsn. at 800 deg.C in the air for 6hr. The multiple oxide has a large specific surface area and effectively occludes NOx even at high temp. |
