Improving the stability of direct-methane solid oxide fuel cells using anode barrier layers

Solid oxide fuel cells (SOFCs) were characterized with methane as the fuel, both with and without an inert porous layer placed between the anode and the fuel stream. For a given set of operating conditions, SOFCs were stable without coking above a critical current density. The barrier layer decreased the critical current density, e.g. from 1.8 to <0.6 A cm−2 at 800 °C. This much-increased stable operating range is discussed in terms of mass transport through the barrier layer.