催化剂上丙烷氧化脱氢制丙烯

以浸渍法制备VMo/γ-Al₂O₃和VMoMg/γ-Al₂O₃催化剂，考察其催化丙烷氧化脱氢制丙烯的反应活性，采用XRD、UV-Vis DRS和In suit IR对催化剂进行表征。结果表明，V负载质量分数为3%、Mo负载质量分数为7%时的3V7Mo/γ-Al₂O₃催化剂表现出较好的催化性能；添加Mg后催化剂的催化性能有所改善，反应温度500 ℃时，丙烷转化率为18.19%，丙烯选择性74.76%。丙烷和丙烯在3V7Mo/γ-Al₂O₃和3V₇Mo₄Mg/γ-Al₂O₃催化剂上吸附后，C—H键的H与催化剂活性中心的晶格氧发生作用形成H—O键，且3V₇Mo₄Mg/γ-Al₂O₃催化剂上出现C—O键的温度比3V₇Mo/γ-Al₂O₃催化剂高，表明加入Mg有利于提高丙烯选择性。

Oxidative dehydrogenation of propane to propene over VMo/γ-Al2O3 catalysts

VMo/γ-Al₂O₃ and VMoMg/γ-Al₂O₃ catalysts were prepared by the impregnation method.The properties of the as-prepared catalysts for the oxidative dehydrogenation of propane to propene were investigated.The catalysts were characterized by XRD,UV-Vis DRS and In suit IR.The results showed that 3V₇Mo/γ-Al₂O₃ catalyst with V and Mo mass fraction of 3% and 7% exhibited better catalytic performance than other catalysts.The performance of the catalysts added with magnesium was greatly improved.Propane conversion of 18.19% and the selectivity to propene of 74.76% were obtained over 3V₇Mo₄Mg/γ-Al₂O₃ catalyst under the condition of reaction temperature 500 ℃.After propane and propene were adsorped on 3V₇Mo/γ-Al₂O₃ and 3V7Mo4Mg/γ-Al₂O₃ catalysts,H—O bond formed due to the interaction of H of C—H bond with lattice oxygen of the activity center of catalysts.The C—O bond appeared when the temperature reached a certain value.The temperature of C—O bond appearing on 3V₇Mo₄Mg/γ-Al₂O₃ catalyst was higher than that on 3V₇Mo/γ-Al₂O₃ catalyst.It indicated that the addition of magnesium was good for improving the selectivity to propylene.