Low-Overpotential High-Activity Mixed Manganese and Ruthenium Oxide Electrocatalysts for Oxygen Evolution Reaction in Alkaline Media

Abstract

Mixed Mn/Ru oxide thermally prepared electrodes using different compositions of Mn and Ru precursor salts have been fabricated on Ti supports via thermal decomposition at two annealing temperatures. Subsequently, the oxygen evolution reaction (OER) activities of these electrodes were determined. A majority of the mixed Mn/Ru catalysts are highly active for the OER, exhibiting lower overpotential values compared to those of the state-of-the-art RuO 2 and IrO 2 type materials, when measured at a current density of 10 mA cm −2 . These Mn/Ru oxide materials are also cheaper to produce than the aforementioned platinum group materials, therefore rendering the Mn/Ru materials more practical and economical. The Mn/Ru catalysts are also evaluated with respect to their Tafel slopes and turnover frequency numbers. Interestingly, scanning electron microscopy reveals that the morphologies of the electrodes change to a mud-cracked morphology, similar to that of the RuO 2 , with minimal amounts of the Ru precursor salt added to the Mn salt. Fourier transform infrared spectroscopy and X-ray diffraction show that the Mn material fabricated in this study at the two annealing temperatures is largely Mn 3 O 4 , while the Ru material is predominately RuO 2 . X-ray photoelectron spectroscopy was also used to investigate the Mn and Ru composition ratios in each of the films.

Nanoparticle-Stacked Porous Nickel–Iron Nitride Nanosheet: A Highly Efficient Bifunctional Electrocatalyst for Overall Water Splitting

“…As shown in Figure S1C, the diffraction characteristic peaks could be well indexed to Ni 3 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 4 been successfully synthesized. By annealing the Ni 3 Fe LDHs precursor at 400 under NH 3 atmosphere, the Ni 3 FeN was synthesized.…”

“…The NSP-Ni 3 FeN electrocatalysts are synthesized by a simple nitridation reaction with the corresponding LDHs. Firstly, Ni 3 Fe LDHs precursors grown on nickel foam (denoted as Ni 3 Fe LDHs/NF) are synthesized by a typical hydrothermal reaction.…”

IrO2 and Pt Doped Mesoporous SnO2 Nanospheres as Efficient Electrocatalysts for the Facile OER and HER

“…Compared to IrO 2 , RuO 2 showed better OER activity but less stability in a strongly acidic medium and partial leaching of RuO 2 during the reaction . IrO 2 nanoparticles supported over high surface area materials are the most effective OER catalysts due to its high activity and stability in acidic environments .…”

Transition Metal-Modified Zirconium Phosphate Electrocatalysts for the Oxygen Evolution Reaction

“…The OER is important for many renewable energy conversion technologies, such as photoelectrochemical cells, regenerative fuel cells, and electrolyzers [1,4,5]. In acid systems, Ir and Ru-based oxides are common catalysts for the OER, while in alkaline environments non-precious transition metal oxides based on Ni, Fe, and Co are commonly employed [6][7][8][9][10]. In all cases, OER catalysts suffer from considerable overpotential losses, limiting the efficiency of hydrogen generation by water electrolysis processes [11].…”