Our group revealed the negative effect of Ni doping into SrFe_1.5Mo_0.5O_6-d as cathode for CO₂ electroreduction in solid oxide electrolysis cells. Ni doping decreases the perovskite stability under electroreduction conditions, Fe and Ni cations in the B-site are reduced to metal nanoparticles and SrCO₃ forms on the surface of the perovskite. This work has been published in Journal of Energy Chemistry, 2019, 36, 87-94.