Bimetallic Mn/Co-MOF from Electronic Waste for Enhanced Electrochemical Nitrogen Reduction

The rapid accumulation of spent lithium-ion batteries (LIBs) presents both an environmental challenge and a resource opportunity. Conventional recycling focuses on regenerating battery-grade materials, requiring stringent control of metal purity and composition. Here, we directly upcycle waste battery leachate into a bimetallic Mn/Co-MOF-74 electrocatalyst without introducing additional Mn precursors, leveraging the compositional complexity of battery waste for electrochemical nitrogen reduction (EN₂RR). The resulting Mn/Co-MOF exhibits enhanced EN₂RR performance compared with pristine Co-MOF, achieving an NH₃ yield of 88.9 µg_NH3·h^-1·mg_cat ^-1 (at -0.3 V vs. RHE) and the highest FE_NH3 to 27.2% (at -0.15 V vs. RHE). Mechanistic investigations confirm an associative reaction pathway and verify dinitrogen as the ammonia source. Density functional theory calculations reveal that Mn incorporation induces local lattice distortion and elongates the axial Co-O bond, strengthening Co-NNH interactions and lowering the energy barrier of the rate-determining step. Integration into a nanofibrous membrane electrode further increases the NH₃ yield (113.8 µg_NH3·h^-1·mg_cat ^-1) and FE_NH3 (29.1%). This work establishes a waste-to-catalyst strategy that exploits battery-waste heterogeneity for sustainable ammonia production under ambient conditions.