填充惰性材料对甲烷部分氧化反应的影响

采用柠檬酸法和浸渍法制备了VOx/Co1yFeyMoO、MoOx/Co0.9Fe0.1MoO复合氧化物催化剂,结合Raman和XRD手段对催化剂进行了表征。在固定床反应器上考察了催化剂对甲烷氧化的催化性能。通过在催化剂床层上部气相空间填充惰性材料,考察了甲烷氧化反应中气相自由基反应对催化反应的影响。空管中填充惰性材料后,在一定程度上抑制了气相自由基反应。催化反应时,催化剂床层上部空间无填充惰性材料时,气相自由基反应依然存在;在催化剂床层上部空间填充惰性材料也可以减少气相自由基的影响。填充惰性材料可以排除气相自由基反应的干扰,显示出催化剂(如VOx/Co0.9Fe0.1MoO)的“真实”的活性。

Influence of Filling Inert Stuffing on Methane Partial Oxidation

VO_x/Co_ 1-yFe_yMo-O and MoO_x/Co_ 0.9Fe_ 0.1Mo-O composite oxide catalysts were prepared by citric acid sol-gel method and impregnation method, and characterized by XRD and Raman. Catalytic activity of the catalysts in the oxidation of methane was examined in a continuous flow type fixed-bed reactor at 400-500℃ and 2.0MPa. The influence of filling inert stuffing on the partial oxidation of methane was investigated by fully filling inert material into the space of empty reactor or into the upper space of catalyst bed. In the case of using empty quartz tube reactor without a catalyst, gas phase radical reaction of methane occurred at the temperature above 420℃ and the pressure of 2.0MPa. When fully filling the empty tube reactor with inert stuffing, the radical reaction was depressed at a certain extent. In the case of the existence of the catalyst but without filling the inert stuffing in the catalyst bed, it was evident that gas phase radical reaction of methane still occurred at the temperature above 420℃ and the pressure of 2.0MPa. However, when fully filling the inert material in catalyst bed, the influence of the radical reactioncould be decreased at the same conditions and the “real” catalytic activity of the catalyst (such as VO_x/Co_ 0.9Fe_ 0.1Mo-O) could be revealed.