Reframing Nitrate Electrochemical Reduction Research toward Practical Electrified Membrane Systems

Nitrate pollution poses significant environmental and health risks. Electrochemical reduction of nitrate (NO3RR) provides a promising alternative for sustainable pollution control and resource recovery. Despite extensive research on nitrate reduction, the engineering application of NO3RR remains underexplored, with many studies focused on H-cell reactors. However, the H-cell system has limitations in mimicking real-world conditions and scaling up processes. Electrified membranes (EMs), as a promising complementary approach, integrate catalytic functions into membrane structures, enhancing mass transfer and reaction rates through spatial confinement and electric fields within the membrane pores. This allows for efficient nitrate reduction and nitrogen or ammonia production in large-scale continuous-flow systems. This perspective reviews the current state of EMs in NO3RR, highlighting the need to optimize key parameters such as catalyst selection and reaction mechanisms. Future work should focus on scaling up EMs systems, improving catalyst stability, and enhancing operational efficiency to address nitrate electroreduction sustainably and economically.