Boron doping induced strong anchor effect between bimetal NiCo alloy and carbon support for efficient electrocatalytic nitrate reduction to ammonia

The electrochemical reduction of nitrate to ammonia presents a promising alternative to the conventional Haber-Bosch process. In this study, a bimetallic NiCo alloy embedded in metal-organic framework derived carbon layer with B doping electrocatalyst NiCo@BC was first successfully developed, which exhibits excellent electrochemical nitrate reduction to ammonia (ENO3RR) performance. In-depth in situ experiments and a machine-learning potential (MLP)-based simulation reveal that B doping within the carbon layer has a crucial anchor effect that induces strong binding between bimetal NiCo alloy and carbon support. Moreover, B doping leads to a decrease in the coordination numbers around the metals, which results in a reduction of the excessively strong intermediates adsorption in the ENO3RR process, thereby significantly enhancing catalytic activity. The fabrication strategy of this electrocatalyst provides a new avenue on ENO3RR research.