Formation of ethane and ethylene by the reaction of methane and carbon dioxide over unsupported metal oxides

Abstract

Publisher Summary This chapter discusses the formation of ethane and ethylene by the reaction of methane and carbon dioxide over unsupported metal oxides and focuses on the effectiveness of metal oxide on C 2 formation from CH 4 and CO 2 and elucidation of the catalytic performance of lanthanide (Ln) oxides with high C 2 selectivity. In an experiment presented in the chapter, the reaction of CH 4 and CO 2 was carried out with a quartz-made fixed-bed reactor under atmospheric pressure. Thirty oxides including alkaline earth, rare earth, and transition metal oxides were used in these reactions. The reaction of CH 4 and CO 2 proceeded over all the oxides examined, except for CuO, which reacts only with CH 4 . The conversion ratios of CH 4 to CO 2 with most oxides were approximately 1:2, which means that CH 4 and CO 2 reacted overall with a molar ratio of 1:2. Most of lanthanide oxides show higher selectivity of C 2 H 6 and C 2 H 4 when the reaction of CH 4 and CO 2 is carried out at 850°C using the thirty oxides. Praseodymium (Pr) and terbium (Tb) catalysts are more effective for C 2 formation among lanthanide oxides. The lattice oxygen atoms in Pr and Tb oxides are very mobile and, thus play a crucial role in C 2 formation.