Boron phosphide as an efficient metal-free catalyst for nitrate electroreduction to ammonia

Abstract

Boron phosphide (BP) is first explored as an efficient metal-free catalyst towards the NO₃RR, delivering the highest NH₃-faradaic efficiency of 96.3% with a corresponding NH₃ yield rate of 3.1 mg h⁻¹ cm⁻², outperforming most reported metal-based NO₃RR catalysts. Theoretical calculations unravel that active B centers not only enable the efficient NO₃⁻ activation and hydrogenation with a low energy barrier, but also preferentially absorb NO₃⁻ over H adatoms to prohibit the competing hydrogen evolution, enhancing both NO₃RR activity and selectivity.