Unlocking the potential of manganese oxide for acidic water electrolysis

<p>The shortage of rare-metal iridium poses a significant threat to producing green hydrogen, which is crucial for achieving carbon neutrality by 2050. This highlights the urgent need for earth-abundant catalyst alternatives. However, the widespread use of earth-abundant catalysts like Fe, Ni, Mn, and Co oxides for water electrolysis is severely hindered by their poor stability in acidic conditions. To overcome this issue, it is necessary to identify and expand the stable potential windows, which is the potential range that the catalyst maintains kinetic activity without dissolution. The effectiveness of this approach was demonstrated using manganese (Mn)-based oxides, particularly γ-MnO₂, which exhibit exceptionally stable water electrolysis even under highly acidic conditions. Accordingly, this perspective envisions the new potential of Mn-based oxides in electrochemical processes, including not only proton exchange membrane (PEM) water electrolysis, but also electrochemical mining and water treatment, ushering in a new era of acid-stable anodic catalyst in electrochemical fields.</p>