Amorphous Iron–Manganese Oxyfluorides, Promising Catalysts for Oxygen Evolution Reaction under Acidic Media

The development of earth-abundant catalysts for the oxygen evolution reaction (OER) in acidic media represents a significant challenge context polymer electrolyte membrane (PEM)-based electrolysis. In this scope, transition metal oxides constitute an emerging alternative to Ir and Ru oxides. Notably, Mn are among few that have sufficient stability electrolytes, but their performance still lacks behind Ir/Ru To end, modification oxides’ structure, crystallinity (or amorphous structure), and/or composition may work enhance catalytic activity. report, we focused our attention on mixed-metal Mn–Fe-based containing highly electronegative fluorine ions as acid-stable OER catalysts. Inspired by recent preparation Mn-Fe-based fluorinated materials MnFe2F8(H2O)2 MnFe2F5.8O1.1, new hydrated fluoride, MnFeF5(H2O)2, was prepared microwave-assisted solvothermal synthesis its subsequent thermal treatment under air yielded corresponding oxyfluoride MnFeF4.6O0.2. resultant structure were determined from powder X-ray diffraction (XRD), Mössbauer spectrometry, analyses, electronic microscopies. crystalline-hydrated fluorides (MnFeF5(H2O)2 MnFe2F8(H2O)2) oxyfluorides (MnFeF4.6O0.2 MnFe2F5.8O1.1) subsequently evaluated first time electrocatalysts (0.5 M H2SO4) media. featured sustained activity at 10 mA/cm2 more than h and, thus, present important addition growing library alternatives