| abstract |
PURPOSE: To regenerate a hetero-polyacid type catalyst, of which the activity is deteriorated, to a catalyst showing catalytic capacity same to or more than that of the initial catalyst with good reproducibility, by treating said deteriorated catalyst with a nitrogen-containing heterocyclic compound. n CONSTITUTION: A catalyst, which is an oxidation catalyst used in producing methacrylic acid by the catalytic gaseous phase oxidation of metacrolein and isobutylaldehyde, and contains hetero-polyacid such as molybdenic acid or molybdovanadinic acid or a hetero-poliacid salt thereof in the composition thereof and is deteriorated in its activity, is dispersed in water without being isolated as compounds of respective constitutional elements while one or more of a nitrogen-containing heterocyclic compound selected from pyridine, pyperidine, pyrimidine, quinoline, isoquinoline and derivatives thereof is added to tne resulting dispersion to treat the deteriorated catalyst. n COPYRIGHT: (C)1985,JPO&Japio |