Intermetallic PtSnNanosheets with p–d OrbitalHybridization for Selective Hydroxylamine Electrosynthesis

The electrocatalytic nitrate reduction to hydroxylamine (NH₂OH) is a challenging catalytic process that has gained significant attention. However, its performance is hindered by the low selectivity of the electrocatalysts. Here, intermetallic PtSn nanosheets with p–d orbital hybridization have been synthesized, which significantly enhances the performance of electrocatalytic nitrate reduction to NH₂OH. The Faradaic efficiency of NH₂OH reaches a maximum of 82.83 ± 1.55% at −0.10 V versus the reversible hydrogen electrode (vs RHE), and the yield of NH₂OH achieves 6.15 ± 0.32 mmol h^–1 mg_cat^–1 at −0.25 V vs RHE. Mechanistic studies reveal that p–d orbital hybridization between p-block Sn and d-block Pt effectively enhances nitrate adsorption and NH₂OH desorption to boost electrochemical NH₂OH synthesis. Given their excellent performance in the electrochemical synthesis of NH₂OH, PtSn nanosheets are utilized as the cathode in an alkaline-acid hybrid Zn–NO₃^– battery to facilitate the production of NH₂OH, achieving an NH₂OH FE of 80.42%.