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研究了催化剂的制备条件 (焙烧方式、焙烧气氛和焙烧温度 )对Mo V Te Nb O上丙烷选择氧化制丙烯酸反应的影响 .结果表明 ,制备条件对催化剂的催化性能具有很大的影响 .与敞开式焙烧制得的催化剂相比 ,封闭式焙烧制得的催化剂具有较高的丙烯酸选择性 ,但丙烷转化率较低 .在空气中焙烧制得的催化剂对丙烯酸无选择性 ,但在氮气和氩气中焙烧制得的催化剂具有很高的丙烷转化率和丙烯酸选择性 .随着焙烧温度的升高 ,丙烷转化率降低 ,丙烯酸选择性升高 ,适宜的焙烧温度为6 0 0℃ .催化剂制备条件对催化剂的晶相结构也具有重要的影响 .在惰性气氛中采用 6 0 0℃下封闭式焙烧制得的Mo V Te Nb O催化剂经 2 10h反应后 ,丙烷转化率保持为 19% ,而丙烯酸选择性持续升高 ,由 32 %升至 5 0 % .
The effects of preparation conditions (calcination mode, calcination atmosphere and calcination temperature) on the selective oxidation of propane to acrylic acid over Mo V Te Nb O were investigated. The results show that the preparation conditions have great influence on the catalytic performance of the catalyst. Compared with the catalyst prepared by calcination, the catalyst prepared by closed calcination has higher selectivity to acrylic acid but lower propane conversion.The catalyst prepared by calcination in air has no selectivity to acrylic acid, but under nitrogen and argon The catalyst prepared by calcination in air has high propane conversion and selectivity to acrylic acid.With the increase of calcination temperature, the conversion of propane decreases and the selectivity of acrylic acid increases.The optimum calcination temperature is 600 ℃ .Preparation of catalyst The conditions also have an important effect on the crystal structure of the catalyst.The propane conversion was maintained at 19% after 2h reaction with Mo V Te Nb O catalyst prepared by closed calcination at 600 ℃ in an inert atmosphere Acrylic acid selectivity continued to rise from 32% to 50%.