摘要 |
PCT No. PCT/JP98/03083 Sec. 371 Date Apr. 2, 1999 Sec. 102(e) Date Apr. 2, 1999 PCT Filed Jul. 9, 1998 PCT Pub. No. WO99/02262 PCT Pub. Date Jan. 21, 1999A denitration catalyst for use in the reduction of nitrogen oxides contained in an exhaust gas containing highly deliquescent salts as dust with ammonia, which bears thereon a porous coating of a water-repellent organic resin, a porous coating of a mixture of a water-repellent organic resin with inorganic oxide particles, or a porous coating of a mixture of a water-repellent organic resin with catalyst component particles. The denitration catalyst can be prepared, for example, by coating the surface of a denitration catalyst with an aqueous dispersion containing a water-repellent organic resin having a lower concentration, drying the coating, further coating the dried coating with an aqueous dispersion containing a water-repellent organic resin having a higher concentration, and then drying the coating to form a porous coating of a water-repellent organic resin. This denitration catalyst, even when used in the treatment of an exhaust gas containing ash containing highly deliquescent salts, enables the water-repellent porous coating formed on the surface to prevent the salts that have deliquesced from entering the catalyst. This can prevent the deterioration of the catalyst and enables a high catalytic activity to be maintained for a long period of time.
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