Dynamic Proton Allocation Drives High‐Efficiency Nitrate Electroreduction on High‐Entropy Alloy Aerogels Across Broad Concentration Ranges

Abstract

ABSTRACT Efficiently reducing nitrate across wide‐range concentrations in wastewater remains a major challenge for electrochemical nitrate reduction (NO 3 RR) to ammonia (NH 3 ), 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 NH 3 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 NH 3 formation. These results highlight the pivotal role of proton management across wide‐ranging nitrate concentrations in NO 3 RR, demonstrating the potential for integrating sustainable chemical synthesis with environmental restoration.