The Effect of Potassium Carbonate on the Catalytic Properties for Methane Conversion with Ceria

Pure CeO 2 and a series of (x %) K-CeO 2 (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 °C. The XRD measurement showed that doping of K 2 CO 3 did not change the structure of CeO 2 with the addition of K 2 CO3 without formation of Ce-K-O solid solution in these materials. Surface area of catalysts was Subscript text decreased with the impregnation amount of K 2 CO 3 . Reducibility of catalysts was obviously enhanced by the addition of K 2 CO 3 as shown in H 2 -TPR tests. The catalysts activity tests indicated that adding K 2 CO 3 to CeO 2 could promote the oxygen storage capacity of catalysts. K species in CeO 2 could affect the CO formation in methane oxidation.