Manganese MOF-derived ruthenium-doped Mn_<i>x</i>O_<i>y</i> catalyst for enhanced oxygen evolution reaction and energy-efficient lead recovery

Advanced, efficient, and eco-friendly technologies are essential for the safe recycling of spent lead-acid batteries for minimizing their environmental impact by mitigating toxic wastes and promoting resource sustainability by recovering valuable lead. Herein, we proposed a simple, zero-emission electrochemical strategy to recover metallic lead <i>via</i> the direct electrolysis of lead-acid batteries. Mn_<i>x</i>O_<i>y</i>@RuO₂ with a layered structure of stacked nanosheets was prepared <i>via</i> facile hydrothermal and annealing methods. Mn_<i>x</i>O_<i>y</i>@RuO₂ exhibited low overpotentials of 175 mV and 248 mV at a current density of 10 mA cm^-2 in 0.5 mol L^-1 H₂SO₄ and Pb(MSA)₂, respectively, showcasing its excellent OER activity. Notably, the catalyst exhibited excellent stability for over 10 hours. The Mn_<i>x</i>O_<i>y</i>@RuO₂ catalyst during constant current electrolysis required an overpotential of only 375.6 mV at 25 mA cm^-2 to function, greatly reducing the precipitation of PbO₂. Mn_<i>x</i>O_<i>y</i>@RuO₂ facilitated high-efficiency oxygen evolution reaction using the lead MSA electrolyte, suppressing the PbO₂ formation and reducing the anode overpotential, making it an ideal anode material for energy-efficient lead recovery.