Low temperature thin film solid oxidefuel cells with nanoporous ruthenium anodes for direct methane operation

Abstract

Thin film micro-solid oxide fuel cells (µSOFCs) utilizing nanoporous ruthenium (Ru) anodes were fabricated and investigated for direct methane operation for the first time. The µSOFCs consist of 8 mol% yttria-stabilized zirconia (YSZ) thin film electrolytes, porous platinum (Pt) cathodes and porous Ru anodes, fabricated on silicon platforms by physical vapor deposition. The fuel cells, tested with methane as the fuel and air as the oxidant, exhibited an open circuit voltage (OCV) of 0.71 V and a peak power density of 450 mW cm⁻² at 500 °C without visually detectable carbon deposition. Structural investigations revealed that the morphology evolution in nanoporous Ru anodes was strongly dependent on the fuels (namely, methane or hydrogen) used, and possible mechanisms leading to the observations are discussed. Results presented here project insights to enable direct use of hydrocarbons with high performance, and are of potential relevance to advancing low temperature micro-fuel cell technology for portable power.