异丁烷催化脱氢反应中钼基催化剂载体效应的研究

采用浸渍法分别制备了以Al2O3，SiO2，ZrO2，MgO，MgAl2O4为载体的MoO3质量分数为5%的Mo基催化剂，利用XRD，BET，NH3-TPD，H2-TPR等分析手段对催化剂进行表征，同时考察不同载体的Mo基催化剂对异丁烷脱氢反应的催化性能。结果表明，Mo/MgAl2O4催化剂具有最佳的异丁烷脱氢反应催化性能，在反应温度为560 ℃的条件下，异丁烯的单程收率可达33.00%。这主要是由于与其它载体相比，以MgAl2O4为载体的Mo基催化剂具有适宜的比表面积，有利于活性Mo物种的分散；此外，该催化剂具有适量的弱酸性位及合适的氧化还原性，可有效地活化异丁烷，并有利于产物异丁烯的脱附，从而保证了较高的烯烃选择性。

EFFECT OF SUPPORT ON ISOBUTENE DEHYDROGENATION REACTION OF Mo BASED CATALYSTS

A series of Mo-based catalysts with 5 wt% Mo loading based on different support, including Al2O3, SiO2, ZrO2, MgO and MgAl2O4, were prepared by incipient wetness impregnation method and characterized by XRD，BET，NH3-TPD，H2-TPR. The isobutane dehydrogenation activity tests show that 5Mo/MgAl2O4 catalyst exhibits the maximum single pass yield of isobutene (up to 33 w %) at 560 ℃. The characterization results of XRD, BET, NH3-TPD and H2-TPR reveal that compared with the other supports，Mo/MgAl2O4 possesses relatively large specific surface area which facilitates uniform distribution of Mo species. Besides, appropriate acid and redox properties of the catalysts also contribute to effective activation of isobutane and easy desorption of isobutene. Consequently, relatively high isobutane conversion and isobutene selectivity are achieved.