Nanoscale High-Entropy Materials for Electrocatalytic Nitrogen Cycling

Promovendus/a: Hele Guo

Promotor(en): Prof. dr. Johan Hofkens

Nitrogen-based compounds such as ammonia and nitric acid are vital for producing fertilizers, medicines, and many industrial products. However, they are traditionally manufactured through energy-intensive industrial processes that consume large amounts of fossil fuels and emit substantial carbon dioxide. This thesis explores electrocatalytic nitrogen conversion as a cleaner and more sustainable alternative that uses electricity from renewable sources to convert nitrogen gas or nitrate pollutants into valuable chemicals under mild conditions. The research focuses on a new class of catalysts called high-entropy materials (HEMs), which contain multiple metallic elements uniformly mixed at the atomic level. Their unique structure provides outstanding stability and tunable electronic properties, enabling them to accelerate slow reactions and improve selectivity. By designing nanoscale HEMs, this work demonstrates efficient catalytic systems for both the nitrogen oxidation reaction (NOR), which produces nitric acid, and the nitrate reduction to ammonia (NRA). Overall, the study provides new insights and practical strategies for designing advanced materials that could make chemical production and environmental remediation more sustainable in the future.