Self-Armoring Non-Noble High-Entropy Alloys with CNT Networks for Ultra-Stable Acid Water Electrolysis

Recent advances in high-entropy alloys (HEA) have demonstrated that the electrocatalytic performance of non-noble metals can be enhanced to levels comparable to those of noble metals through the synergistic effects of multiple elements. However, non-noble HEA systems still encounter inherent stability challenges caused by electrolyte corrosion, particularly under acidic conditions. Here, a highly stable non-noble HEA catalyst for acid water electrolysis is realized through self-armoring them with a self-supporting and self-protecting 3D interlocking CNT network. The CNT networks confer robust chemical corrosion resistance to the catalyst, while the synergistic effects of the multi-element composition enable the catalyst to have superior electrocatalytic activity. Remarkably, the catalyst maintains stable operation for over 600 h without significant performance decay. The overpotentials of 48 and 226 mV at 10 mA cm^-2 in 0.5 M H₂SO₄ for the hydrogen evolution reaction and the oxygen evolution reaction are achieved, respectively. This self-armoring strategy establishes a pathway to overcome intrinsic stability limitations in non-noble HEA catalysts, supporting scalable deployment of non-noble HEA under aggressive electrochemical environments.