Intelligent Responsive Armored Aerogel for Efficient Natural Seawater Electrolysis at High Current Density

Abstract Natural seawater electrolysis faces significant challenges due to the complex seawater environment, particularly the formation of insoluble deposits on the cathode that block active sites. Here, an intelligent phthalocyanine‐armorized Ru aerogel electrocatalyst is introduced that exhibits exceptional hydrogen evolution reaction (HER) performance and outstanding stability at industrial current densities in natural seawater. The intelligent armor promotes the dissociation of water and self‐captures protons to build the acidic microenvironment, creating a positively charged layer that shields against Mg and Ca cations in seawater. This intelligent armor continuously responds throughout the electrolysis process, offering dynamic, long‐term protection to the electrode. The unsaturated Lewis acid sites in the center of the phthalocyanine binds to OH ⁻ , slowing down the rise of the pH and avoiding the formation of precipitation. Additionally, the armor significantly reduces the HER energy barriers of the Ru aerogel, enhancing its intrinsic catalytic activity. Consequently, the aerogel demonstrates an overall water‐splitting voltage of 2.35 V and maintains stability for over 250 hours at industrial current densities. The intelligent responsive armor presented here offers a promising strategy to advance the efficiency and durability of direct natural seawater electrolysis.