Pt-Mediated Co-Adsorption of Hydroxyl and Nitrogen-Heterocyclic Species Over Cu/CuO Heterostructure Enhances Coupled Azotriazole Electrosynthesis and Dual-Electrode Hydrogen Production.

Electrocatalytic N─N oxidative coupling (OC) offers an eco-friendly approach to produce value-added azo materials, but suffers from sluggish kinetics and limited Faradaic efficiency (FE). The key fundamental issue is unfavorable competitive adsorption of hydroxyl groups and N-heterocyclic species. Here, a Pt-immobilized Cu/CuO heterostructure is designed to create energy-favorable N─N OC of N-heterocyclic diaminotriazole (DATOC). Operando spectroscopy along with theoretical calculations reveal that the immobilization of Pt nanoclusters (NCs) in Cu/CuO mediates adsorption capacities for both N-heterocyclic substrates/intermediates and OH- species on Cu sites of Cu/CuO, collaboratively promoting DATOC kinetics. While the N─N intermediates are effectively adsorbed on Pt─Cu sites via metal-N coordination. Consequently, the Pt@Cu/CuO catalyst only requires 0.832 and 0.904 VRHE to achieve 10 and 100 mA cm-2, respectively, with a high FE of 95%. Due to the low-potential DATOC, the adsorbed hydrogen atom from N─H cleavage of aminotriazole undergoes counterintuitive self-coupling to H2. As a result, the dual-electrode H2 production requires an electricity input of only 1.15 kWh per m3 of H2. The exceptional catalytic durability of the coupled system is also demonstrated in a flow electrolyzer for 600 h@500 mA cm-2. This work provides a new perspective for highly efficient green azo electrosynthesis and low-energy-consumption H2 production.