Enhancement of Catalytic Activity and Stability of La0.6Ca0.4Fe0.7Ni0.3O2.9 Perovskite with ppm Concentration of Fe in the Electrolyte for the Oxygen Evolution Reaction

Sergei V Porokhin; Victoria A Nikitina; Artem M Abakumov

doi:10.3390/ma14216403

Enhancement of Catalytic Activity and Stability of La_0.6Ca_0.4Fe_0.7Ni_0.3O_2.9 Perovskite with ppm Concentration of Fe in the Electrolyte for the Oxygen Evolution Reaction

Materials (Basel). 2021 Oct 26;14(21):6403. doi: 10.3390/ma14216403.

Authors

Sergei V Porokhin¹, Victoria A Nikitina¹, Artem M Abakumov¹

Affiliation

¹ Center for Energy Science and Technology, Skolkovo Institute of Science and Technology, Nobel Street 3, 143026 Moscow, Russia.

Abstract

The catalytic activity and stability of an iron-nickel based oxygen-deficient perovskite for the oxygen evolution reaction (OER) are drastically improved with the ppm additive of Fe ions to the alkaline electrolyte. The enhancement is attributed to a 1-2 nm restructured Ni_0.5Fe_0.5O_x(OH)_2-x (oxy)hydroxide layer, as demonstrated with scanning transmission electron microscopy. La_0.6Ca_0.4Fe_0.7Ni_0.3O_2.9 shows almost a four-fold increase in OER activity after Fe addition relative to the as-prepared pristine electrolyte, which demonstrates the low Tafel slope of 44 ± 2.4 mV dec^-1 and the superior intrinsic activity of 706 ± 71 A g^-1_oxide at 1.61 V vs. RHE.

Keywords: lattice oxygen mechanism; oxygen evolution reaction; perovskite; water splitting.