The effect of different resin supportson activity and stability of Co catalyst for the oxidation of p-cresol to p-hydroxybenzadehyde

摘要

Four kinds of supported cobalt oxide catalysts using different resins as support were prepared. Their activity, selectivity and )tability were observed for the air oxidation of p-cresol to p-hydroxybenzadehyde (P-HBA) in methanolic sodium hydroxide )olution at 348 K. In the observational experiments, it. was found that three kinds of supported cobalt oxide catalysts using general macroporous resins as support were all of good catalytic activity, over 85% conversion of p-cresol and over 95% selectivity to p-HBA obtained within 8 h of reaction, but the stability of these catalysts was related to each resin's composition and polarity. The reasons for the effect of the resin supports on the stability of the catalysts were discussed. Some microinfor- mation on the resin supports and the active component on the surface of support fere obtained by X-ray diffraction (XRD) and IR analyses of catalysts. As a result, the macroporous strongly acidic action exchange resin -D072 -with 20--40 mesh was selected as an ideal support of Co catalyst for the oxidation of p-cresol to p-HBA, because D072-supported cobalt oxide catalyst exhibited both extremely high activitY and good stability, retaining over 91% of conversion of p-cresol and selectivitY to p-HBA as well as a stable cobalt content after it was used four times.