Angew. Chem. Int. Ed. - High-Entropy Metallene Aerogels: A New Balancer for *H Production and Consumption in Nitrate Reduction Reaction

Hanjun Li, Zhen Huang, Yimin Wang, Guangtong Hai*, Wei-Hsiang Huang*, Chun-Chi Chang, Min-Hsin Yeh, Feili Lai, Nan Zhang*, Tianxi Liu*

Angew. Chem. Int. Ed. 2025, DOI: 10.1002/anie.202505156

High-entropy metallene aerogels (HEMAs), synergizing high-entropy metallenes and metallic aerogels, face challenges in achieving single-phase structures due to multi-metallic nucleation/growth disparities, hindering two-dimensional anisotropic growth and three-dimensional assembly of multi-component nanocrystals. Herein, the universal preparation of HEMAs was achieved by a seed-mediated synthetic route for electrochemical nitrate reduction reaction (NO3RR). PdCuSnCoNi HEMAs exhibit maximum Faradaic efficiency and yield rate of NH3 up to 99.5% and 4117.8 µg h−1 mgcat.−1, surpassing those of Pd metallene aerogels (MAs). In situ attenuated total reflection infrared absorption spectroscopy, online differential electrochemical mass spectrometry and density functional theory calculations reveal kinetic match for *NO3 to *NO2 and *NO2 to *NH3, with the energy barrier for *NO2 formation (potential-determining step) being lower than that for *H to H2, balancing production and consumption of *H and facilitating NH3 generation on PdCuSnCoNi HEMAs. This study paves the way for efficient NO3RR catalysts and guides rational design for diverse electrocatalytic systems.

Link: https://doi.org/10.1002/anie.202505156