METHOD FOR SUPPORTING NOx OCCLUDING MATERIAL AND METHOD FOR PRODUCING NOx OCCLUSION-REDUCTION CATALYST

摘要

PROBLEM TO BE SOLVED: To easily and reliably support an NOx occluding material as hyperfine particles of several ten nm or below.;SOLUTION: A compound of an NOx occluding element and a powdery carrier are suspended in a polar solvent having a lower relative dielectric constant than water and CO2 is supplied to the polar solvent. Since the carbonate of the NOx occluding element formed by the reaction of a cation of the NOx occluding element with a carbonate ion has very low solubility in the polar solvent, nucleation occurs instantaneously by contact with the CO2, the carbonate of the NOx occluding element becomes a highly supersaturated state and many nuclei are formed. Since dissolution and deposition are not repeated in the polar solvent, the formed nuclei are supported on the powdery carrier while almost retaining the particle diameter. The nuclei are supported as hyperfine particles of about several nm particle diameter.;COPYRIGHT: (C)2001,JPO