Abstract: Cobalt chromium mixed oxide ultrafine particle catalysts were prepared by coprecipitation and sol-gel methods. The catalytic properties of catalysts for catalytic oxidation of 2,3,6-trimethylphenol to trimethyl-p-benzoquinone were investigated.It is shown that the catalyst with Co/Cr=1 prepared by sol-gel method is the best.The structures of catalysts were characterized by TEM,XRD and DTA-TG.The mixed oxide is amorphous under 350℃.The thermal stability of this amorphous catalyst is higher than that of Co₃O₄ and Cr₂O₃.

Key words: cobalt chromium mixed oxide, ultrafine particle, catalyst, preparation, structure, catalytic oxidation, trimethylphenol, trimethyl-p-benzoquinone