Efficient H2O2 Electrosynthesis via Strategic Regulation of Sulfur Coordination in Single-atom Catalysts, Chemical Engineering Journal 521, 166571(2025)
Song-Chi Chen, Shih-Wei Lin, Shao-Lun Chang, Ying-Rui Lu*, Chih-Jung Chen*
2025/11/24
Electrochemical oxygen reduction reaction (ORR) powered by green electricity offers a sustainable approach for H2O2 production. Commonly used cobalt single-atom catalysts (Co-SACs) with four nitrogen-coordinated active sites (CoN4) motifs often demonstrate a strong affinity for intermediates, resulting in limited H2O2 selectivity. Our research explored converting wheat flour into supports for Co-SACs by integrating sulfur into the coordination environment, significantly affecting the ORR pathway. By adjusting the pyrolysis temperature, disulfide bonds in gluten were transformed into sulfur atoms located either in the external or first coordination shells of metal sites, forming C–S or Co–S bonds. This C–S configuration lowered the d-band center of the metal species, moderating the adsorption of intermediates during ORR. In-situ X-ray absorption spectroscopy (XAS) confirmed the durability of this atomic structure throughout the reaction process. However, Co–S coordination reduced electrochemical stability and contributed to the formation of metal oxide clusters in the ORR process, promoting the 4-electron pathway by enhancing O–O bond cleavage. The optimized Co-SAC achieves a H2O2 production rate of 50.5 mmol gcatalyst−1 h−1 in an acidic electrolyte, reaching a concentration of about 42.8 mM, suitable for medical disinfection and household sanitation. Additionally, the electro-Fenton process was demonstrated to effectively remediate phenol pollutants in wastewater.
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