摘要
The mechanism of partial oxidation of methane was studied on Pt/Alb>2b>Ob>3b>, Pt/ZrOb>2b> and Pt/Ce–ZrOb>2b> catalysts. The reducibility and oxygen transfer capacity were evaluated by temperature programmed reduction (TPR) and oxygen storage capacity (OSC). The effect of the support on the cleaning mechanism of the catalyst surface was investigated by the sequence of CHb>4b>/Ob>2b> pulses. Moreover, temperature programmed surface reaction (TPSR) measurements were performed to evaluate the reaction mechanism. Pt/Ce–ZrOb>2b> catalysts proved to be more active, stable and selective than Pt/Alb>2b>Ob>3b> and Pt/ZrOb>2b> catalysts. The results were explained by the higher reducibility and oxygen storage/release capacity of Pt/Ce–ZrOb>2b> catalysts, which allowed a continuous removal of carbonaceous deposits from the active sites, favoring the stability and activity of the catalysts, as revealed by the CHb>4b>/Ob>2b> pulses. TPSR experiments showed that the partial oxidation of methane proceeded through a two-step mechanism.