| 摘要 |
<p>The invention relates to the stabilization of the activity and/or the reactivation of molybdoheteropoly acid catalysts in vapor-phase oxidations, such as the oxidehydrogenation of isobutyric acid or its lower esters to methacrylic acid or its lower esters, by means of an oxidizing treatment of the catalyst in which compounds of catalyst constituents are added, at temperatures ranging from 200 DEG to 400 DEG C., with an oxygen-containing gas. The inventive activation measures can be carried out either during the catalytic vapor-phase reaction, such as oxihydrogenation in particular, or intermittently to alternate therewith, and optionally also physically separated in part from each other.</p> |
