The effect of potassium carbonate on the catalytic properties for methane conversion with ceria

Pure CeO2 and a series of (x %) K-CeO2 (x=1, 2, 3, 4) catalysts were respectively prepared by the precipitation and incipient wetness impregnation methods, and characterized by means of XRD, BET and H-2-TPR techniques. The catalytic activity was investigated by the gas-solid reaction with methane in the absence of gaseous oxidant in a fixed bed reactor at 800 degrees C. The XRD measurement showed that doping of K2CO3 did not change the structure of CeO2 with the addition of K2CO3 without formation of Ce-K-O solid solution in these materials. Surface area of catalysts was decreased with the impregnation amount of K2CO3. Reducibility of catalysts was obviously enhanced by the addition of K2CO3 as shown in H-2-TPR tests. The catalysts activity tests indicated that adding K2CO3 to CeO2 could promote the oxygen storage capacity of catalysts. K species in CeO2 could affect the CO formation in methane oxidation.