| 摘要 |
PURPOSE:To attain a high rate of removal of NOx by using a catalyst for removal of NOx contg. metal substd. mordenite represented by a specified formula in which the metal has (<=80 (kcal/gram atom of oxide) oxide forming enthalpy. CONSTITUTION:Commercially available N type mordenite is immersed in 0.1N HCl soln., 1-3N NH4Cl soln., etc., at ordinary temp. or under heating to substitute H<+> or NH<+> for part of Na<+> and to prepare acid type mordenite satisfying (z-c)/x<=0.40. This mordenite is immersed in 1-3N HCl soln. to prepare acid type mordenite satisfying y/x>=5. This mordenite is further immersed in a soln. of the chloride of a metal M having <=80 oxide forming enthalpy - Hf deg. to substitute the metal M for part of H<+> and to prepare metal substd. mordenite represented by a formula {MA.H(x-z-B).Na(z-C). [(AlO2)x.(SiO2)y]mH2O where M is a multivalent metal whose valence is (B+C)/A and A/x>=0.3}, A high rate of removal of NOx is attained by using a catalyst contg. the metal substd. mordenite. |
