Enhancement of the oxygen evolution reaction in Mn³⁺-based electrocatalysts: correlation between Jahn–Teller distortion and catalytic activity

Abstract

We systematically studied the catalytic activity of the oxygen evolution reaction (OER) for the tetragonal spinel oxide Mn3-xCoxO4 (0 ≤ x < 1 and 1 < x ≤ 1.5). The OER catalytic activity of Mn3-xCoxO4 (0 ≤ x < 1) dramatically improved with an increase in Co content. We found that the OER activity of Mn3-xCoxO4 (0 ≤ x < 1) increased linearly with the suppression of the Jahn-Teller distortion. We therefore propose that the Jahn-Teller distortion plays an important role in the OER activities of compounds containing Mn 3+ . Mn3-xCoxO4 (0 ≤ x < 1) provides a rare case for directly studying the effect of the Jahn-Teller distortion on OER activity.

Some Attributes of Mn3+ Sites in Nickel‐Based Layered Double Hydroxides during Methanol Electro‐oxidation in Alkaline Media

“…This phenomenon can be attributed to Mn 3 + ability to remove the charge density on oxygen atom in MÀO bond, decreasing the effective charge on oxygen in MOÀH bond, particularly, on four MnÀO shorter bonds caused by Jahn-Teller distortions, [23] NiAl and NiMn LDH also exhibited the presence of m(Ni 3 -OH) configuration with 4.7 eV for proton removal as was reported previously. [11] …”

Electrospun Cu‐Deposited Flexible Fibers as an Efficient Oxygen Evolution Reaction Electrocatalyst

“…17 mV dec −1 lower than that of Cu plate, implying the improved OER rate on a Cu/PVdF‐HFP fibrous catalyst. The obtained Tafel slope value is little larger than the layered transition metal catalyst (e. g. 40 mV dec −1 for NiFe‐LDH in 1 M KOH), comparable with the transition metal oxide catalyst (e. g. 60 mV dec −1 for Mn 3 O 4 in 1 M KOH) as well as the precious metal oxide catalysts (e. g. 55 mV dec −1 for RuO 2 and 91 mV dec −1 for IrO 2 in 0.5 M KOH), and smaller than the most of the perovskite‐based catalysts (70 mV dec −1 for LaCoO 3 and 91 mV dec −1 for La 0.8 Sr 0.2 O 3 in 1 M KOH). It is unlikely that the unique fibrous structure of Cu/PVdF‐HFP fiber catalyst affects the energetics of the OER; the much higher specific OER activity of Cu/PVdF‐HFP fiber compared to the Cu plate is probably due to the synergetic effect between Cu and PVdF‐HFP …”

Thermally Prepared Mn2O3/RuO2/Ru Thin Films as Highly Active Catalysts for the Oxygen Evolution Reaction in Alkaline Media

“…A similar study in base by Hirai et al. compared pure Mn 2 O 3 for the OER by using Mn 2 O 3 mixed with different amounts of Co oxide . The specific activity of the various Co/Mn oxide ratios were compared at a potential of 1.76 V versus a reversible hydrogen electrode (RHE), and the results demonstrated that, with increasing amounts of Co oxide compared to Mn 2 O 3 , an increase in OER performance was observed.…”

“…measured the Jahn–Teller distortion, which occurs when the axial bonds are shorter than the elongated bonds in respect to the central atom, and found that a suppression of the Jahn–Teller distortion occurred with increasing Co content. Therefore, they suggested that the suppression of the bonds to a more compressed structure is likely to contribute to the better OER performance of the Co/Mn oxide compared to pure Mn 2 O 3 . Other elements including palladium and gold have also been used to increase the OER activity of Mn oxide …”