Pulsed Electrolysis Prevents Sulfur Poisoning for Sustained Sulfide Valorization

Abstract

ABSTRACT Hydrogen sulfide (H 2 S), a toxic byproduct generated from metallurgy, incineration, and natural gas purification, poses serious environmental and health risks. Current treatments (e.g., the Claus process) are energy‐intensive and generate secondary waste. Electrochemical sulfide oxidation (SOR) offers an energy‐efficient alternative for simultaneous H 2 S removal and recovery of high‐purity hydrogen and sulfur, but its application is hindered by anode deactivation due to sulfur deposition. Here, we report a dynamic microenvironment engineering strategy using pulsed electrolysis (PE) to achieve sustainable SOR. Coupled with a Sc‐doped NiFe‐LDH electrocatalyst optimized for intermediate adsorptions, we achieve periodical modulation of metal‐sulfur redox, enabling efficient sulfur release and active site regeneration. This synergy enables continuous H 2 S destruction and hydrogen production for over 500 h with a Coulombic efficiency of 99.8% and a low energy consumption of 2.19 kWh m −3 . Furthermore, using bio‐derived formic acid, the acidification process is capable of co‐production high‐purity sulfur (99.5%) and sodium formate. This integrated process, validated also with industrial syngas and seawater electrolyte, increases the overall profit by 121% to US$1,294.7 per tonne of hydrogen. Overall, this report demonstrates a circular and economically viable strategy for H 2 S treatment and resource recovery, which is also implacable to other electrochemical systems facing catalyst poisoning.