| 摘要 |
PURPOSE:To obtain the catalyst for purifying exhaust gas by depositing the zeolite dealuminized by boiling the zeolite particles with hydrochloric acid or hydrothermally treating the particles on a refractory carrier and further depositing Cu thereon by ion exchange. CONSTITUTION:The ZSM-5 zeolite synthesized by occluding tetrapropylammonium ion into zeolite and removing the ion by calcination or the zeolite having the pore diameter and SiO2/Al2O3 ratio equivalent to those of the above-mentioned zeolite is dealuminized. The zeolite is dealuminized by boiling the zeolite particles with hydrochloric acid or hydrothermally treating the particles in the heated atmosphere contg. a large amt. of steam, and the Al/Si ratio is controlled to about 50-250. A slurry is prepared from the dealuminized zeolite, a refractory carrier is wash-coated with the slurry which is then calcined, and ions are exchanged by the conventional method to deposit Cu on the carrier. The catalyst for purifying exhaust gas thus produced exhibits excellent heat resistance and purifying performance over a long period. |
