The Sm-2 - xSrxCuO4 - d is single-phase with a tetragonal structure across compositional range 0 < x < 0.5. Sm2.8SrO2CuO4 - d.exhibits maximum dc conductivity (6.8(2) S cm(-1) at 640 degrees C) and minimum activation energy (E-a = 0.400(6) eV) among studied solid solutions. Minimum polarization resistance (R-p) value of 1.57(3) Omega cm(2) is obtained at 700 degrees C for Sm2.8SrO2CuO4 - d. Low-frequency impedance spectra are modeled using Gerischer element Magnitude of Gerischer impedance decreases significantly with increase in Sr content. Oxygen partial pressure-dependent polarization study suggests that non-charge transfer oxygen-adsorption desorption and diffusion are important steps during overall oxygen reduction reaction processes. (C) 2014 Elsevier B.V. All rights reserved.