Interfacial Electronic Interactions Induced by Self‐Assembled Amorphous RuCo Bimetallenes/MXene Heterostructures for Nitrate Electroreduction to Ammonia

Electrocatalytic nitrate reduction to ammonia (NO₃RR) is an attractive green route to generate valuable ammonia and remove nitrates in industrial processes. However, under the intense competition of hydrogen evolution reactions (HER), it is a key challenge to improve the selectivity and reduce the energy consumption of the nitrate reduction reaction. Herein, a unique amorphous RuCo Bimetallenes confined on Ti₃C₂T_x-MXene (RuCo/Ti₃C₂T_x) is reported as a highly efficient NO₃RR catalyst, showing a remarkable Faradaic efficiency for ammonia of 94.7% at -0.2 V versus reversible hydrogen electrode (RHE), with the corresponding high ammonia yield rate of 98.8 mg h^-1 mg_cat ^-1 at -0.6 V versus RHE. Significantly, the RuCo/Ti₃C₂T_x heterostructures are able to operate stably at 1 A cm^-2 for over 100 h under membrane electrode assembly (MEA) conditions with a stabilized NH₃ Faraday efficiency. In-depth theoretical and operando spectroscopic investigations unveil that the in situ generation of heterojunction via interfacial Ru/Co─O bridges can induce charge redistribution through Ru/Co─O-Ti structure and modulate the electronic structure of RuCo Bimetallenes, significantly promoting ^*H production and the adsorption and activation of reactants/intermediates, while suppressing HER, thereby boosting NO₃RR performance. This study offers a new insight the metal-support interaction for the development of high-performance electrocatalysts.