Abstract
Acidic seawater electrolysis offers significant advantages in high efficiency and sustainable hydrogen production. However, in situ electrolysis of acidic seawater remains a challenge. Herein, a stable and efficient catalyst (SPTTPAB/IrO(2)) is developed by coating iridium oxide (IrO(2)) with a microporous conjugated organic framework functionalized with sulfonate groups (-SO(3)H) to tackle these challenges. The SPTTPAB/IrO(2) presents a -SO(3)H concentration of 5.62 × 10(-4) mol g(-1) and micropore below 2 nm numbering 1.026 × 10(16) g(-1). Molecular dynamics simulations demonstrate that the conjugated organic framework blocked 98.62% of Cl(-) in seawater from reaching the catalyst. This structure combines electron conductivity from the organic framework and proton conductivity from -SO(3)H, weakens the Cl(-) adsorption, and suppresses metal-chlorine coupling, thus enhancing the catalytic activity and selectivity. As a result, the overpotential for the oxygen evolution reaction (OER) is only 283 mV@10 mA cm(-2), with a Tafel slope of 16.33 mV dec(-1), which reduces 13.8% and 37.8% compared to commercial IrO(2), respectively. Impressively, SPTTPAB/IrO(2) exhibits outstanding seawater electrolysis performance, with a 35.3% improvement over IrO(2) to 69 mA cm(-2)@1.9 V, while the degradation rate (0.018 mA h(-1)) is only 24.6% of IrO(2). This study offers an innovative solution for designing high-performance seawater electrolysis electrocatalysts.