New insights into intermediate-temperature solid oxide fuel cells with oxygen-ion conducting electrolyte act as a catalyst for NO decomposition

Abstract

The environmental problems and supply of clean and economical energy is grand global challenges. Direct decomposition of nitrogen oxides (NOx) is the most ideal and effective approach for NOx removal by catalysis, which has the great potential to alleviate the air pollution. On the other hand, solid oxide fuel cells (SOFCs) are one of the cleanest, most efficient chemical-to-electrical energy conversion systems. Here we reported a new electrochemical system to combine the traditional catalyst for direct decomposition of NOx with an electric generation process through a SOFC. By nano-sized La0.4Ba0.6Mn0.8Mg0.2O3–δ (LBMM), an effective catalyst widely used for NOx decomposition, adopting an anode-support SOFC configuration, which consisted with the conventional NiO-samarium doped ceria (SDC) anode, and thin film SDC electrolyte, we demonstrated that complete decomposition of NOx and a peak power density of 25mWcm−2 at 600°C when Ar containing 5% NO and 5% O2 was fed to the cathode and 10% H2 was used the fuel. The effect of the ratio between NO and O2 was found to be critical for the NO conversion and SOFC performance. The dependence of temperature and gas composition on NO conversion was also investigated.