Entropy-Engineered Middle-In Synthesis of Dual Single-Atom Compounds for Nitrate Reduction Reaction

Abstract

Despite the immense potential of Dual Single-Atom Compounds (DSACs), the challenges in their synthesis process, including complexity, stability, purity, and scalability, remain primary concerns in current research. Here, we present a general strategy, termed "Entropy-Engineered Middle-In Synthesis of Dual Single-Atom Compounds" (EEMIS-DSAC), which is meticulously crafted to produce a diverse range of DSACs, effectively addressing the aforementioned issues. Our strategy integrates the advantages of both bottom-up and top-down paradigms, proposing an insight into optimizing the catalyst structure. The as-fabricated DSACs exhibited excellent activity and stability in the nitrate reduction reaction (NO₃RR). In a significant advancement, our prototypical CuNi DSACs demonstrated outstanding performance under conditions reminiscent of industrial wastewater. Specifically, under a NO₃^- concentration of 2000 ppm, it yielded a Faradaic efficiency (FE) for NH₃ of 96.97%, coupled with a mass productivity of 131.47 mg h^-1 mg^-1 and an area productivity of 10.06 mg h^-1 cm^-2. Impressively, even under a heightened NO₃^- concentration of 0.5 M, the FE for NH₃ peaked at 90.61%, with a mass productivity reaching 1024.50 mg h^-1 mg^-1 and an area productivity of 78.41 mg h^-1 cm^-2. This work underpins the potential of the EEMIS-DSAC approach, signaling a frontier for high-performing DSACs.