Electrochemical Nitric Oxide Reduction on Metal Surfaces

Electrocatalytic denitrification is a promising technology for removing NO x species (NO 3 − , NO 2 − and NO). For NO x electroreduction (NO x RR), there is a desire for understanding the catalytic parameters that control the product distribution. Here, we elucidate selectivity and activity of catalyst for NO x RR. At low potential we classify metals by the binding of *NO versus *H. Analogous to classifying CO 2 reduction by *CO vs. *H, Cu is able to bind *NO while not binding *H giving rise to a selective NH 3 formation. Besides being selective, Cu is active for the reaction found by an activity‐volcano. For metals that does not bind NO the reaction stops at NO, similar to CO 2 ‐to‐CO. At potential above 0.3 V vs. RHE, we speculate a low barrier for N coupling with NO causing N 2 O formation. The work provides a clear strategy for selectivity and aims to inspire future research on NO x RR.