Total Oxidation of Methane Over La, Ce and Y Modified Manganese Oxide Catalysts

A series of catalysts based on high specific surface area MnO₂ precursor, and modified by La, Ce or Y ions were prepared and applied for methane deep oxidation. XRD and BET results indicate that La, Ce and Y ions as additives can impede the crystallization of catalysts at high temperatures. Thus, some catalysts that can maintain much higher specific surface area than unmodified MnOx were obtained. The main species of all catalysts are proved to be crystalline or amorphous Mn₂O₃ by XRD and H₂-TPR. The activities for methane total oxidation over these catalysts are compared with each other. It is found that all modified catalysts show higher activities than unmodified MnOx below 420°C, but show a little lower activity above this temperature.