Dynamic Proton Allocation Drives High-Efficiency Nitrate Electroreduction on High-Entropy Alloy Aerogels Across Broad...

Efficiently reducing nitrate across wide-range concentrations in wastewater remains a major challenge for electrochemical nitrate reduction (NO₃RR) to ammonia (NH₃), where the dynamic control of active proton is critical. Here we proposed a dynamic proton allocator strategy featuring adaptive control of active proton availability in response to local nitrate levels. Applied to high-entropy alloy aerogels, this approach achieved >90% Faradaic efficiencies (FE) over a wide nitrate concentration range from 0.01∼1.0 M, nearly an order-of-magnitude increase in NH₃ yield rate compared to other catalysts at identical nitrate concentrations. In situ spectroscopic investigations revealed that the high-entropy element distribution modulated molecular structure of interfacial water, enhancing active proton availability for nitrate hydrogenation. Theoretical calculations demonstrated that the unique high-entropy electronic configuration optimized intermediate adsorption, shifted the rate-determining step and lowered the reaction energy, promoting NH₃ formation. These results highlight the pivotal role of proton management across wide-ranging nitrate concentrations in NO₃RR, demonstrating the potential for integrating sustainable chemical synthesis with environmental restoration.