MOF membrane boosts electrocatalytic nitrogen reduction on perovskite oxides

The electrochemical nitrogen reduction reaction (NRR) under ambient conditions presents a promising approach for the eco-friendly and sustainable synthesis of ammonia, with a continuous emergence of potential electrocatalysts. However, the low solubility and limited diffusion of N₂ significantly hinder the achievement of satisfactory performance. In this context, we report an effective strategy to enhance NRR activity by introducing a metal–organic framework (MOF) membrane, specifically MIL-53(Al), onto a perovskite oxide (LiNbO₃), denoted as LN@MIL-X (X = 0.2, 0.4 and 0.6). The MIL-53(Al) membrane selectively recognizes and concentrates N₂ at the catalyst interface while simultaneously repelling water molecules, thereby inhibiting the hydrogen evolution reaction (HER). This ultrathin nanostructure significantly improves the NRR performance of LN@MIL-X compared to pristine LiNbO₃. Notably, LN@MIL-0.4 exhibits a maximum NH₃ yield of 45.25 μg h^-1 mg_cat.^-1 with an impressive Faradaic efficiency (FE) of 86.41% at -0.45 V versus RHE in 0.1 mol L^-1 Na₂SO₄. This work provides a universal strategy for the design and synthesis of perovskite oxide electrocatalysts, facilitating high-efficiency ammonia synthesis.