High-efficiency electrocatalytic nitrate-to-ammonia conversion over CoPd alloy nanoparticles embedded within carbon...

Electrocatalytic nitrate reduction reaction (NO₃RR) to ammonia (NH₃) provides a promising, environmentally benign, and energy-efficient strategy to eliminate nitrate (NO₃^-) pollution within the nitrogen cycle while simultaneously producing a valuable chemical feedstock. Herein, we report the synthesis of bimetallic CoPd alloy nanoparticles embedded within carbon nanofibers (CNFs) via a two-step electrospinning and carbonization approach, designed specifically for high-performance NO₃RR. The interconnected CNFs provide robust structural support, ensuring excellent catalyst stability and cycling performance. Remarkably, the optimized Co₂Pd₁-CNF catalyst delivers exceptional NO₃RR activity, achieving a high NH₃ yield rate of 43.6 ± 0.7 mg h^-1 cm^-2 at -0.7 V vs. RHE, alongside outstanding long-term stability exceeding 100 h of continuous operation, greatly surpassing not only the single-metallic Co-CNFs and Pd-CNFs but also most recently reported NO₃RR electrocatalysts. Moreover, the integration of Co₂Pd₁-CNFs as the cathode into an aqueous Zn-NO₃^- battery demonstrates its practical utility, yielding an impressive power density of 9.28 mW cm^-2. This work highlights CoPd-CNFs as a highly efficient and durable catalyst for sustainable NO₃^- removal, simultaneously enabling valuable ammonia synthesis and demonstrating promising applicability in next-generation energy storage devices.