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

Electrocatalytic nitrate reduction reaction (NORR) to ammonia (NH) provides a promising, environmentally benign, and energy-efficient strategy to eliminate nitrate (NO) 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 NORR. The interconnected CNFs provide robust structural support, ensuring excellent catalyst stability and cycling performance. Remarkably, the optimized CoPd-CNF catalyst delivers exceptional NORR activity, achieving a high NH yield rate of 43.6 ± 0.7 mg h cm 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 NORR electrocatalysts. Moreover, the integration of CoPd-CNFs as the cathode into an aqueous Zn-NO battery demonstrates its practical utility, yielding an impressive power density of 9.28 mW cm. This work highlights CoPd-CNFs as a highly efficient and durable catalyst for sustainable NO removal, simultaneously enabling valuable ammonia synthesis and demonstrating promising applicability in next-generation energy storage devices.