Iron-based heterogeneous catalysts are ideal metal catalysts owing to their abundance and low-toxicity. However, conventional iron nanoparticle catalysts exhibit extremely low activity in liquid-phase reactions and lack air stability. Previous attempts to encapsulate iron nanoparticles in shell materials toward air stability improvement were offset by the low activity of the iron nanoparticles. To overcome the trade-off between activity and stability in conventional iron nanoparticle catalysts, we developed air-stable iron phosphide nanocrystal catalysts. The iron phosphide nanocrystal exhibits high activity for liquid-phase nitrile hydrogenation, whereas the conventional iron nanoparticles demonstrate no activity. Furthermore, the air stability of the iron phosphide nanocrystal allows facile immobilization on appropriate supports, wherein TiO₂ enhances the activity. The resulting TiO₂-supported iron phosphide nanocrystal successfully converts various nitriles to primary amines and demonstrates high reusability. The development of air-stable and active iron phosphide nanocrystal catalysts significantly expands the application scope of iron catalysts.

铁基多相催化剂因其储量丰富、毒性低而成为理想的金属催化剂。然而，传统的铁纳米粒子催化剂在液相反应中表现出极低的活性并且缺乏空气稳定性。先前尝试将铁纳米颗粒封装在壳材料中以改善空气稳定性，但由于铁纳米颗粒的低活性而被抵消。为了克服传统铁纳米粒子催化剂活性和稳定性之间的权衡，我们开发了空气稳定的磷化铁纳米晶体催化剂。磷化铁纳米晶体对液相腈氢化表现出高活性，而传统的铁纳米颗粒没有表现出活性。此外，磷化铁纳米晶体的空气稳定性允许容易地固定在合适的载体上，其中TiO ₂增强了活性。所得TiO ₂负载的磷化铁纳米晶体成功地将各种腈转化为伯胺，并表现出高可重复使用性。空气稳定且具有活性的磷化铁纳米晶催化剂的开发显着拓展了铁催化剂的应用范围。