Oxidation of acetic acid on Co$z.sbnd;Bi composite oxide catalysts

The complete oxidation of acetic acid on CoBi composite oxide catalysts was investigated with a comparison of their activity for the oxidation of toluene. CoBi composite oxides (Co/Bi · ox) with Bi contents of 10–20 mol% exhibited high activity for the oxidation of acetic acid, and a reduced CoBi composite oxide catalyst (Co/Bi · red) containing as much as 55 mol% of Bi had the same activity as a reduced Co catalyst. However, both catalysts were not as active for the oxidation of toluene as for the oxidation of acetic acid. Temperature-programmed desorption experiments showed that the high activity of Co/Bi · ox for the oxidation of acetic acid was due partly to the strong affinity of Bi for acetic acid. The addition of Bi up to 20 mol% increased the surface area of Co/Bi · ox which was another factor contributing to the high activity of the catalyst for the oxidation of acetic acid. Both Co/Bi · ox and Co/Bi · red exhibited larger compressive strength than the corresponding Co catalyst without Bi.