Structural effects of LaNiO3 as electrocatalyst for the oxygen reduction reaction

Abstract LaNiO 3 perovskite is a promising electrocatalyst for the oxygen reduction reaction (ORR). In this work we study the effects of several key structural and morphological features on the performance of LaNiO 3 perovskites for the ORR. We have prepared a series of LaNiO 3 oxides via soft chemistry and calcined the final materials at different temperatures from 500 to 1000 °C. With the aim of obtaining morphological and structural information relevant to their performance the prepared oxides have been thoroughly characterized by BET, Power Neutron Diffraction (PND), XRD, HRTEM, STEM-HAADF and XPS. We have analysed the effect of extrinsic (surface area and particle size) and intrinsic factors (formation of oxygen vacancies, Ni oxidation states and occupancy of the e g levels) on the current densities and specific activity, respectively, of several samples of LaNiO 3 . The catalysts with higher catalytic activity are those in which the perovskite structure is properly formed, but display high surface areas.