Palladium metallene for nitric oxide electroreduction to ammonia.

We demonstrate Pd metallene as an efficient catalyst for electrocatalytic NO reduction to NH 3 (NORR), showing the maximum NO-to-NH 3 faradaic efficiency of 89.6% with a corresponding NH 3 yield rate of 112.5 μmol h -1 cm -2 at -0.3 V in neutral media. Theoretical calculations unveil that NO can be effectively activated and hydrogenated on the hcp site of Pd through a mixed pathway with a low energy barrier.