Boron‐Induced d–sp Orbital Hybridization Tailors Ruthenium Electronic Structure for Efficient Nitrate Electroreduction

Abstract Modulating the electronic structure of ruthenium (Ru) and harnessing its intrinsic hydrogenation activity toward nitrogen‐containing intermediates are crucial for developing efficient Ru‐based catalysts for the nitrate reduction reaction (NO 3 RR). In this work, theoretical calculations reveal that among a series of light elements, the boron (B) atom can be stably incorporated into the Ru lattice. The strong d–sp orbital hybridization between Ru and B effectively modulates the coordination environment and electronic structure of Ru atoms, thereby promoting the hydrogenation of nitrogen‐containing intermediates. This electronic modulation enhances the catalytic activity and selectivity of Ru for NO 3 RR, making the Ru–B system a promising candidate for electrochemical ammonia (NH 3 ) production. Guided by these theoretical insights, a Ru–B alloy is successfully synthesized using a simple chemical reduction method. Structural characterizations confirm uniform B incorporation within the Ru framework. Electrochemical measurements demonstrate that the Ru–B catalyst delivers a Faradaic efficiency of 99.1% and an NH 3 yield of 13.10 mg h −1 mg cat −1 under ambient conditions. This study highlights the potential of light‐element doping as a general strategy for engineering high‐performance noble metal catalysts for sustainable nitrogen‐based transformations.