Study On Mixed Metal Oxide Catalysts In Selective Oxidation Of Propane To Acrylic Acid

In this paper, the influence of the hour, temperature ,concentration, pH value,as well as the reactant feeding mode of Mo-V-Te and Nb-oxalate in hydration reaction towards catalysts performances were researched.Furthermore,different calcining means and temperature,as well as calcination atmospheres and temperature were reviewedWe researched the effect of adding metal element lanthanum, bismuth, iron, cobalt, nickel and wortle in the process of preparing mixed metal oxide catalysts precursor. we prepared Mo-V-Te-Nb-O catalysts by using TeO₂ as Te source.Then,we researched the stability of catalysts.We prepared catalysts by hydration reaction in condition of transfering nothing butone agential. Then baked catalysts in the modes of heat-drying and gyrate-evaporation drying at uniform temperature.We calcined catalysts in the atmosphere of nitrogen-stop-page,nitrogen-flow,air-stoppage and air-flow after that.Finally The performances of Mo-V-Te-Nb-O catalysts were appraised in a fixed bed microreactor.The experimental results proclaimed how the law factors affected performances of prepared catalysts. Catalysts performances advanced in company with the increasing of Mo-V-Te hydration reaction hour and temperature respectively,and then catalysts perfor-mances were stable when temperature and hour were exceeding. Catalysts performancesadvanceed in company with the increasing of Mo-V-Te-Nb hydration reaction hour and temperature respectively, and then catalysts performances were stable when temperature and hour were exceeding.The catalysts performances got better in company with the in-creasing of concentration in hydration reaction. The performances of catalysts presented to depress after increased when pH value in hydration reaction of Mo-V-Te-Nb varied,and the best catalyst performance presented 2.0 to 2.5.The best reactant feeding mode was that Nb-oxalic acid leaning into Mo-V-Te solution directly.Moreover,the most outst-anding facters were pH value and reactant feeding mode. The mode of dryness should select gyrate-evaporation drying at 50℃,and calcination should choose nitrogen-stoppagecalcination at 600℃.Experiments confirmed that catalysts performances will be poor w-hen joining metallic element into Mo-V-Te-Nb-O catalysts. We prepared Mo-V-Te-Nb-O catalysts by using TeO2 as Te source,which catalysts activities were not fine at all.In this text,the stability of catalyst were reviewed,but only found that catalysts performanc-es were not stable at all.The catalysts were inactive after 283h.