High‐Entropy Metallene Aerogels: A New Balancer for *H Production and Consumption in Nitrate Reduction Reaction
Hanjun Li, Zhen Ying Huang, Yimin Wang, Guangtong Hai, Wei‐Hsiang Huang, Chun‐Chi Chang, Min‐Hsin Yeh, Feili Lai, Nan Zhang, Tianxi Liu
Abstract
Abstract 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 (NO 3 RR). PdCuSnCoNi HEMAs exhibit maximum Faradaic efficiency and yield rate of NH 3 up to 99.5% and 4117.8 µg h −1 mg cat. −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 *NO 3 to *NO 2 and *NO 2 to *NH 3 , with the energy barrier for *NO 2 formation (potential‐determining step) being lower than that for *H to H 2 , balancing production and consumption of *H and facilitating NH 3 generation on PdCuSnCoNi HEMAs. This study paves the way for efficient NO 3 RR catalysts and guides rational design for diverse electrocatalytic systems.