Department of Chemical Engineering, Imperial College of Science, Technology and Medicine, London, SW7 2BY, UK
Abstract:
A study of the selective oxidative coupling of methane (OCM) to C2 hydrocarbons (ethane and ethylene) in a solid-state electrochemical reactor made from yttria-stabilized zirconia (YSZ) has been made. Three different catalyst–electrode systems based on silver and two trimetallic formulations of Mn modified alkali (Na and K) tungstates supported on silica were used. A comparison is made between co-fed and electrochemically-supplied oxygen. The electrochemically-supplied oxygen gave higher overall C2 selectivities than the co-fed method under low current conditions, which was attributed to differences in local methane to oxygen ratios at the catalyst surface. The potassium tungstate supported catalyst gave the best overall C2 selectivity (86% at 4% C2 yield).