Built‐In Electric Field Regulated Electron Transport Channels of FeP Supported Os for Ampere‐Level Seawater Electrolysis

ABSTRACT Developing cost‐effective and robust hydrogen evolution reaction (HER) catalysts to replace Pt‐based compounds in alkaline media remains a critical challenge. Therefore, FeP experiences ultrafast microwave quasi‐solid process (within 10 s) to construct a heterostructure with Os clusters (Os/FeP). Leveraging the constructed heterostructure, the occurrence of electronic metal‐support interaction (EMSI) within the fabricated Os/FeP contributes to a more rational electronic configuration, while the induced built‐in electric field (BEF) boosts electron transfer, mitigating the excessive H * adsorption on Os sites while enhancing H * coverage on FeP. The Os/FeP exhibits enhanced HER activity of 25, 36 mV@10 mA cm −2 in alkaline freshwater and seawater, respectively. Moreover, the assembled Os/FeP || RuO 2 anion exchange membrane water electrolyzer (AEMWE) exhibits excellent electrocatalytic performance of 1.92 V@1 A cm −2 and continuously operates over 600 h under harsh industrial conditions for seawater electrolysis. The boosted mass/price activity of 9.96 A mg −1 Os and 724.74 A dollar −1 at 2.0 V, in combination with the $0.90 H 2 per GGE well illustrates its economic superiority, suggesting its promising prospects in industrial application. This work represents Os/FeP heterostructure catalyst with BEF and successfully utilizes the EMSI to enhance efficiency, serving as effective approaches of developing robust electrocatalysts with remarkable HER activity in alkaline media.