| 摘要 |
PURPOSE:To obtain a catalyst having very high activity in the decomposition reaction of NO and maintaining its activity over a long time by using crystalline silicate having a specified compsn. and a specified crystal structure. CONSTITUTION:Cu and a rare earth element are incorporated into crystalline silicate having a chemical compsn. represented by a formula (1.0+ or -0.4)R2O. (aM2O3.bAl2O3).ySiO2 (where R is an alkali metal ion and/or an H ion, M is ions of one or more kinds of elements selected among group VIII elements, rare earth elements, Ti, V, Cr, Nb and Sb, a+b=1, a>0, b>0, y>12 and these figures show the molar ratio among the oxides) in a dehydrated state to form a catalyst for decomposition of NO. This catalyst has a wider service temp. range than the conventional catalyst and is used within the range of 300-1,000 deg.C, preferably 400-700 deg.C. |
