Application of High-Entropy Materials in Promoting Electrocatalytic Nitrogen Cycle

Nitrogen cycle is a fundamental biogeochemical loop existed for millions of years, which involves the transformation of nitrogen-containing chemicals in the environment. However, human activities, especially those since the Industrial Revolution, have significantly disrupted this balance, leading to environmental and energy challenges. Electrocatalysis nitrogen cycle (ENC) offers a promising alternative for the sustainable transformation of nitrogen compounds en route toward rebalancing, with reactions such as the electrocatalytic nitrogen reduction reaction (eNRR) and nitrate/nitrite reduction reaction (eNO₃RR/eNO₂RR) emerging as sustainable alternatives to the traditional Haber-Bosch process. However, conventional catalysts are handicapped by instability and linear scaling relationships. High-entropy materials (HEM), characterized by a high entropy of mixing due to the presence of multiple principal elements in nearly equal proportions, have garnered significant attention due to the synergistic effects among different elements, making them attractive candidates for applications in ENC. This review delves into the realm of HEMs and their applications in ENC, which elucidates the nitrogen cycle, the issues of conventional catalysts, definition of HEMs, and their employment in the ENC process. Critical characterizations, especially in situ technologies, are highlighted, and the prospects in this emerging field are discussed. This review could be a reference for future development of HEMs in catalysis.