Methane combustion over supported cobalt catalysts

A series of cobalt-based catalysts with different supports have been prepar ed using impregnation method, and characterised by X-ray diffraction (XRD), laser Raman (LR), and infrared spectroscopy (IR). The catalytic activities for methane combustion were assessed in a micro-reactor. The ZrO2 and Al2O 3 supports are themselves active in methane combustion, and ZrO2 supported cobalt catalyst was found to have the highest activity amongst the TiO2, Al 2O3, MgO supported catalysts and bulk Co3O4. The Co content has a marked ef fect on the activity of the ZrO2 supported catalyst with 1.0 and 15 wt.% of Co having the lowest light-off temperature in methane combustion. In the M gO supported catalyst, Co oxide was highly dispersed over the MgO support s urface or enters the lattice of MgO to form a solid solution, whose activit y for methane combustion is reasonable. The zirconia supported cobalt catal ysts are very active and stable when calcination or reaction temperature is no more than 900 degreesC. Calcining the catalysts at temperatures above 9 00 degreesC for more than I h decreases the catalyst activity. The deactiva tion of the catalyst probably results from the decrease of the surface area . (C) 2001 Elsevier Science B.V. All rights reserved.