(654c) Investigation of the Effect of Pre-Treatment Methods on the Reactivity of Methane, Steam and Oxygen over NiO/CexZr1-XO2

Methane is abundantly available as the major component of natural gas. However, a large fraction of methane resources is not sufficiently utilized due to difficulties in transporting gases from remote locations and the economy of scale in converting methane to high value products, such as steam reforming. Hence, large quantities of methane are vented or flared on site, which is not only a waste of resource, but also causes significant environmental issues. Over the years, many efforts have been put into the task of developing efficient methods for upgrading methane into other products.

Our group has developed a catalyst that consists of well-dispersed nickel oxide clusters on a cerium-zirconium oxide support (NiO/CZ) and is capable of converting methane under moderate conditions. The NiO clusters act as Lewis acid cites and are responsible for activation of methane. The pretreatment method has a significant impact on the reactivity of the catalyst. With different pretreatment method, the surface can be either reduced, wetted, or oxidized. The reaction can shift from methane steam reforming, to combustion of methane, or partial oxidation of methane into alcohols (i.e., methanol and ethanol) depending on the state of the surface. Operando IR spectroscopy is used to monitor the surface species during these reactions to elucidate the mechanism of the reactions.