Partial oxidation of methane to synthesis gas using Ni/Ca0.8Sr0.2TiO3 anode catalyst

A high performance electrochemical reactor for the partial oxidation of CH4 into synthesis gas has been developed by fixing powder catalysts on the anode surface for the natural gas conversion. A powdered catalyst of Ni,Ni-1.0/Ca0.8Sr0.2TiO3, fixed by a gold paste has excellent catalytic activity without significant deactivation by the carbon deposition. The conversion of CH4 at 1173K is 38.8% with the selectivity to CO of 98.9%. The advantage of this system is the separation of N-2 and O-2 in the cathode chamber when using air as the oxidant gas instead of pure oxygen. Furthermore, an electric power density of 14.5 mW cm(-2) has been obtained by this system at 1173 K. The amount of carbon deposition over the Ni-1.0/Ca0.8Sr0.2TiO3 is ten times lower than that over the Niyttria-stabilized zirconia cermet of a typical anode material in the solid oxide fuel cell system or the typical Ni/Al2O3 catalyst for CH, conversion. This is attributed to the oxidation of carbon deposits by the lattice oxygen species that migrated from the oxide to the NiCa0.8Sr0.2TiO3 boundary. The synthesis gas is considered to be formed not only by the steam reforming of CH, including the complete oxidation but also by the direct oxidation of CH4. (C) 2000 The Electrochemical Society. S0013-4651(99)06-109-1. All rights reserved.