Precursor of Pr2NiO4+δ as a highly effective catalyst for the simultaneous promotion of oxygen reduction and hydrogen oxidation reactions in solid oxide electrochemical devices

The electrochemical behaviour of a Sr 2 Fe 1.5 Mo 0.5 O 6–δ based double-layer electrode decorated with a “symmetric” catalyst by the wet impregnation technique for the simultaneous acceleration of cathodic and anodic reactions was investigated for the first time. As a “symmetric” catalyst, a solution of precursor for the synthesis of praseodymium nickelate (Pr 2 NiO 4+δ ) was considered. Since the catalyst consists of NiO and Pr 6 O 11 in an oxidizing atmosphere and of Ni and Pr 2 O 3 in a reducing atmosphere, it effectively accelerates the rate of oxygen reduction at the cathode and hydrogen oxidation at the anode of solid oxide fuel cells with symmetric electrodes. It was shown that the rate of oxygen reduction after introduction of the catalyst into the electrode increased due to an increase in the rate of oxygen interfacial exchange between the electrode and the gas phase. The rate of hydrogen oxidation increased due to an increase in the rate of dissociation of adsorbed hydrogen. During tests of the fuel cell with a 300 μm LaGaO 3 -based supporting electrolyte and decorated electrodes, a maximum power density of about 0.83 W cm −2 at 800 °C under wet hydrogen/air condition was obtained. • The influence of PNO as a symmetrical catalyst for SFM has been first studied. • ASR of decorated SFM electrodes was about 0.065 Ω cm 2 at 800 °C for air and wet H 2 . • The role of PNO in the electrode reactions on SFM was established. • Power density of SOFC with decorated electrodes is about 0.83 W cm −2 at 800°С.