Rational Design of a CoRu Nanoalloy-Embedded Carbon Matrix for Efficient Electrocatalytic Nitrate Reduction

Abstract

The synthesis of ammonia (NH₃) through the electrocatalytic reduction of nitrate (NO₃^–) represents a sustainable and environmentally friendly approach to ammonia production, with significant implications for agricultural and chemical industries. Herein, we report the fabrication of a cobalt–ruthenium nanoalloy embedded in an N-doped carbon matrix (CoRu/NC) for NH₃ synthesis. X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) results show a strong electronic interaction between Co and Ru, which is beneficial for enhancing the catalytic performance. Finally, it shows a remarkable onset potential of 0 V vs reversible hydrogen electrode (RHE) and the highest Faradaic efficiency of 96% for the production of NH₃ at −0.2 V vs RHE. The high performance of CoRu/NC is attributed to the synergistic effect between the Co and Ru nanoalloys and the encapsulated carbon matrix. The desirable component of Ru in the alloy could improve the poor hydrogenation ability of pure Co by providing atomic hydrogen (H*), which would facilitate the hydrogenation of the intermediate nitrogen species during the nitrate reduction process. This work presents a promising strategy for efficient and sustainable ammonia synthesis via nitrate reduction, offering insights into the design of advanced electrocatalysts for energy and environmental applications.