Work up and regeneration of deactivated P-Mo-V-containing heteropolyacid catalysts

摘要

The invention relates to the regeneration of deactivated heteropolyacid catalysts from gas-phase oxidations such as the oxidising dehydrogenation of isobutaric acid or lower esters thereof to form methacrylic acid or lower esters thereof, by treating the used catalyst with a liquid, oxygen-releasing oxidising agent in the presence of compounds for supplementing the catalyst constituents, in particular in the presence of molybdenum compounds, in the temperature range from 5 to 150@C.