Constructing Hollow Tin Dioxide Catalysts via Transition Metal Doping for Electrochemical Synthesis of Ammonia

The electrocatalytic nitrogen reduction reaction (NRR) under mild conditions represents a highly promising route to convert nitrogen into ammonia. However, the intrinsic kinetic barriers of the NRR hinder efficient ammonia synthesis. In this work, transition metal (Fe, Cu) doping hollow tin dioxide (H–SnO ₂ ) is prepared via a straightforward hydrothermal reaction method and evaluated for its electrocatalytic NRR performance. Benefiting from the transition metal doping, the defects and oxygen vacancies are generated in H–SnO ₂ , resulting in the exposure of active sites and substantially enhancement of the electrocatalytic activity. Specifically, the iron (Fe)‐doped variant Fe–SnO ₂ achieves an ammonia yield of 16.92 μg h ^–1 mg _cat. ^–1 and high Faradaic efficiency of 20.82% at –0.3 V versus reversible hydrogen electrode (RHE), demonstrating superior performance relative to pristine H–SnO ₂ . This study offers a novel strategy for fabricating high‐performance NRR catalysts and provides valuable insights into the fundamental aspects of this reaction.