Work

High Catalytic Selectivity of Electron/Proton Dual‐Conductive Sulfonated Polyaniline Micropore Encased IrO 2 Electrocatalyst by Screening Effect for Oxygen Evolution of Seawater Electrolysis

Year: 2024

Type: article

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.

Source: Advanced Science

DOI: 10.1002/advs.202412862