Catalytic activity of spinel oxides MgCr2O4 and CoCr2O4 for methane combustion

Abstract The chrome-containing spinels, MgCr 2 O 4 and CoCr 2 O 4 , were prepared via sol–gel method using glucose as a complexing agent after calcination at 1400 °C and investigated as catalysts for catalytic combustion of methane. XRD indicated that single phase spinel oxides of MgCr 2 O 4 and CoCr 2 O 4 had formed. XPS analysis exhibited that Cr 3+ was present in both catalysts, whereas a small amount of Cr 6+ was only detected in MgCr 2 O 4 . The spinel MgCr 2 O 4 proved to be very active and its catalytic activity reached T 10  = 400 °C and T 90  = 684 °C for methane combustion, which was much superior to that of CoCr 2 O 4 ( T 10  = 480 °C and T 90  = 750 °C). Larger surface area (1.1 m 2 /g), more flexible reactive surface oxygen species, and appropriate surface and bulk structure of MgCr 2 O 4 may contribute to its excellent catalytic activity toward methane combustion.