Electrochemical reduction of NO on La2-x Sr x NiO4 based electrodes

The series La_2 − x Sr _x NiO₄ (x = 0.0, 0.05, 0.15, 0.25, 0.35, and 1.0) was tested for functionality as electrode materials for direct electrochemical reduction of NO. The materials were tested using cyclic voltammetry in 1% NO and 10% O₂ in Ar on a cone-shaped electrode. The best materials for the electrochemical reduction of NO are La₂NiO₄ and LaSrNiO₄, which have current densities for NO reduction 1.82 and 7.09 times higher, respectively, than for O₂ at 400 °C. Increasing the temperature decreased the ability to reduce NO before O₂ while the activity increased. The adsorbed species during direct decomposition was attempted, clarified using X-ray absorption near-edge structure experiments and thermogravimetry, but no conclusive results were obtained.