Bidirectional electron donation in Cu1−Ti pairs on TiOx for efficient nitric oxide electroreduction

Electrocatalytic nitric oxide reduction (NORR) enables the efficient abatement of NO while simultaneously synthesizing valuable ammonia (NH3). However, the strong polarity of NO hinders its effective activation on conventional NORR catalysts because of their single-site interaction mode, wherein either the nitrogen (N) or oxygen (O) atom of NO binds to the catalyst through a unidirectional electron transfer. In this study, we construct dual-atom Cu1−Ti pairs on the titanium oxide (TiOx) substrate by using the complementary affinities of Ti for nitrogen and Cu for oxygen, which simultaneously activates both ends of the N=O bond. The designed Cu1−Ti pairs achieve competitive NORR performance with an NH3 yield of 189.9 μmol h−1 cm−2 and a Faradaic efficiency of 93.7%. In situ techniques and theoretical calculations demonstrate that this dual-atom configuration shifts the mechanism from an end-on adsorption pathway observed on homonuclear pairs to a fully activating side-on mode. By highlighting the importance of adapted active site design in the electrocatalytic activation of polar molecules, this study facilitates the development of next-generation catalysts for complex transformations. Electrocatalytic NO reduction to NH3 is hindered by insufficient NO activation. Here, the authors report Cu1−Ti pairs that integrate the N affinity of Ti and O affinity of Cu to efficiently activate NO via bidirectional electron donation, thus achieving a high NH3 yield and Faradaic efficiency.