A metal-free catalyst for electrocatalytic NO reduction to NH 3 .

Metal-free boron phosphide (BP) is explored for the first time as an effective catalyst for electrocatalytic NO reduction to NH 3 , showing a high NH 3 -faradaic efficiency of 83.3% with an NH 3 yield rate of 96.6 μmol h -1 cm -2 , surpassing most metal-based catalysts. Theoretical results reveal that the B and P atoms of BP can serve as dual-active centers to synergistically activate NO, promote the NORR hydrogenation process and inhibit the competing hydrogen evolution reaction.