Plasma Catalyzed Non-Oxidative Coupling Conversion of Methane to Hydrogen and EthaneAuthor(s): Lee Jennifer
Under standard environmental conditions, methane coupling and plasma pyrolysis were carried out. With varying H2/CH4 ratios and N2 flow rates, methane was coupled through gliding arc plasma with conversion ranging from 25% to 40% and high acetylene selectivity above 90%. Plasma emission spectra showed that the IH/IH ratio was lowest at an H2/CH4 ratio of 3, and that it increased as N2 feed rate increased from 0 L/min to 2 L/min, varying similarly to acetylene selectivity. With increasing Pd loading and Ag/Pd ratio, metallic Pd species (335.4 eV) were transferred to electron rich Pd species (334.8 eV and 334.1 eV), which resulted in a red shift of the linear adsorbed CO stretching frequency from 2060 cm1 to 2068 cm1 to 2055 cm1-2015 cm1. This was shown by X-ray photoelectron spectra for reduced catalysts. With 86.5% selectivity of ethane and 36.2% conversion of methane, superior plasma catalytic performance above 0.1 Pd 0.5 Ag/Al2O3 catalysts has been attained.