Study On Complex Metal Oxides Catalysts For Selective Oxidation Of Isobutane

A series of Mo-V-Te-Nb catalysts were prepared for oxidation of isobutane selectively. The effects of time, temperature in the reaction of Mo-V-Te towards catalyst performance were researched. The effects of time, temperature, pH value and the feeding mode of Mo-V-Te-Nb and Nb-oxalate in the reaction of Mo-V-Te-Nb were researched too. And the metal ratio of the complex metal-oxide catalysts was researched. The mode of dryness and the temperature of dryness were researched such as the mode and the temperature of calcination. The performance of mixed metal-oxide Mo-V-Te-Nb-O catalysts was tested in a fixed bed microreactor, which was feeding continuously.The experimental results showed that the catalyst which elemental composition as Mo1V0.30Te0.23Nb0.12 is better. The Mo-V-Te should be reacted at 80℃for 30 minutes. Also the Mo-V-Te-Nb should be reacted at 80℃for 120 minutes. The mode of dryness should select gyrate-evaporation drying at 50℃, and the nitrogen-stoppage calcination at 600℃should be chosen as the mode of calcination. The results show that, at the temperature of 360℃, the ratio of reating gas was i-C40∶O2∶N2=14:7:43, water content was 12%, total space velocity was 1600h-1 under the conditions of the reaction, i-C4 conversion rate was 12.4%, MAA selectivity was 28.4%, MAA yield was 3.48%. Catalyst performance was not stable at all and catalyst was inactive after 78h.