Synergistic coupling of defective SO x -containing carbon and iron phthalocyanine for efficient oxygen reduction

Iron phthalocyanine (FePc) has emerged as a viable non-precious metal catalyst for the oxygen reduction reaction (ORR), offering a potential substitute for costly precious metals. However, fine-tuning its electronic structure to optimize intermediate adsorption remains a challenge. In this study, we report a significant enhancement of the ORR catalytic activity of FePc through a synergistic interaction with a defective SO x -enriched carbon substrate. Our experimental and theoretical investigations reveal that the introduction of SO x groups via ultrasonication effectively modifies the electronic configuration of the Fe–N 4 center, facilitating the desorption of OH* intermediates. The resulting U-FePc@DSNC catalyst exhibits exceptional catalytic activity and stability in alkaline media, achieving a remarkable half-wave potential ( E 1/2 ) of 0.93 V. This approach offers a promising strategy for precise modulation of the adsorption properties of Fe-based active centers, paving the way for the development of highly efficient and cost-effective ORR catalysts.