File Name : figs1.tif Caption : fig. s1. x-ray diffraction patterns of the la0.6sr0.4mno3 nanopowders (tann = 800, 850, and 900 °c) measured at room temperature and fitted using the rietveld method. the experimental and calculated values (black and red curves), and difference curve (blue line) normalized to a statistical error are presented. vertical bars are calculated positions of diffraction peaks corresponding to the space group. File Name : figs2_a_.tif Caption : fig. s2(a). sem images (top) for the lsmo-800 (left) File Name : figs2_b_.tif Caption : fig. s2(b). sem images (top) for the lsmo-850 (center) File Name : figs2_c_.tif Caption : fig. s2(c). sem images (top) for the lsmo-900 (right) File Name : figs2_d_.tif Caption : fig. s2(d).eds of chemical composition (bottom) for the lsmo-800 (left). File Name : figs2_e_.tif Caption : fig. s2(e).eds of chemical composition (bottom) for the lsmo-850 (center). File Name : figs2_f_.tif Caption : fig. s2(f).eds of chemical composition (bottom) for the lsmo-900 (right). File Name : figs3_a_.tif Caption : fig. s3(a). particle size distribution in the la0.6sr0.4mno3 nanopowders with tann = 800°c according to sem images (inset). File Name : figs3_b_.tif Caption : fig. s3(b). particle size distribution in the la0.6sr0.4mno3 nanopowders with tann = 900°c according to sem images (inset). File Name : figs4_a_.tif Caption : fig. s4(a). approximation of the experimental values of d in the la0.6sr0.4mno3 nanopowders (tann = 800°c) by the gaussian function (sm2) File Name : figs4_b_.tif Caption : fig. s4(b). approximation of the experimental values of d in the la0.6sr0.4mno3 nanopowders (tann = 800°c) by the lorentzian function (sm3) File Name : figs4_c_.tif Caption : fig. s4(c). approximation of the experimental values of d in the la0.6sr0.4mno3 nanopowders (tann = 800°c) by the lognormal function (sm4) File Name : figs4_d_.tif Caption : fig. s4(d). approximation of the experimental values of d in the la0.6sr0.4mno3 nanopowders (tann = 900°c) by the gaussian function (sm2) File Name : figs4_e_.tif Caption : fig. s4(e). approximation of the experimental values of d in the la0.6sr0.4mno3 nanopowders (tann = 900°c) by the lorentzian function (sm3) File Name : figs4_f_.tif Caption : fig. s4(f). approximation of the experimental values of d in the la0.6sr0.4mno3 nanopowders (tann = 900°c) by the lognormal function (sm4) File Name : figs5.tif Caption : fig. s5. approximation of the particle size dispersion d in the lsmo-800 nanopowder by the gaussian function f(d) (d0sem is the average particle size from sem image, 94% of the particles have a size d ≤ 50 nm). File Name : figs6.tif Caption : fig. s6. an approximation of the inverse magnetic susceptibility χ-1(t) = h/m(t) by the curie law for the lsmo-800 nanopowder (θ is the paramagnetic curie temperature, tconset is the temperature of the appearance of fm correlations, and μeff(mn) is the effective magnetic moment of manganese). File Name : figs7_a_.tif Caption : fig. s7(a). cv curves of lsmo-800 electrodes in ar-saturated and o2-saturated 1 m koh at a sweep rate of 10 mv•s-1. File Name : figs7_b_.tif Caption : fig. s7(b). cv curves of lsmo-800 electrodes in ar-saturated and o2-saturated 1 m koh at a sweep rate of 50 mv•s-1. File Name : figs8_a_.tif Caption : fig. s8(a). lsv curves of lsmo-800 electrodes in ar-saturated and o2-saturated 1 m koh at a sweep rate of 1 mv•s-1 (ir-compensation 90%). File Name : figs8_b_.tif Caption : fig. s8(b). lsv curves of lsmo-900 electrodes in ar-saturated and o2-saturated 1 m koh at a sweep rate of 1 mv•s-1 (ir-compensation 90%). File Name : figs9_a_.tif Caption : fig. s9(a). сhronopotentiometry test of lsmo-800 catalyst at the current density of 10 ma•cm-2: cp curve File Name : figs9_b1_.tif Caption : fig. s9(b1). сhronopotentiometry test of lsmo-800 catalyst at the current density of 10 ma•cm-2: photo of electrode corrosion File Name : figs9_b2_.tif Caption : fig. s9(b2). сhronopotentiometry test of lsmo-800 catalyst at the current density of 10 ma•cm-2: photo of electrode corrosion File Name : figs10.tif Caption : fig. s10. the equivalent scheme for eis measurement: rs – solution resistance, rсt – the resistance of electron transfer on a anode; qh – constant phase element (cpe),represents helmholtz layer capacitance; qsc – constant phase element (cpe), represents space charge layer capacitance; rsc is the space charge separation resistance q is the constant phase element (cpe). File Name : figs11_a_.tif Caption : fig. s11(a). cv curves of lsmo electrodes in 1 m na2so4 at different sweep rate: 1 mv•s-1. File Name : figs11_b_.tif Caption : fig. s11(b). cv curves of lsmo electrodes in 1 m na2so4 at different sweep rate: 1 mv•s-1 for within voltages from 1,0 to 1,7. File Name : figs11_c_.tif Caption : fig. s11(c). cv curves of lsmo electrodes in 1 m na2so4 at different sweep rate: 50 mv•s-1.