Rapid water purification enabled by balancing metal and non-metal electron transfer channels in peroxymonosulfate activation

Carbon-supported catalysts hold great promise in environmental remediation. While extensive attention has been paid to the role of transition metal centers, the electron transfer mediated by non-metallic components during peroxymonosulfate (PMS) activation has long been overlooked. In this work, a series of M-hexaaminobenzene (HAB) (M = Fe, Co, Cu) metal-organic frameworks were synthesized to investigate the essential roles of metal and non-metal constituents and their correlation with catalytic expression. In situ spectroscopic characterization and density functional theory calculations indicate that, beyond the electron interaction between metal centers and PMS, hydrogen atoms within the HAB ligands form multiple hydrogen bonds with the terminal oxygen atoms of PMS. The metal and non-metal channels work synergistically to promote PMS activation. Crucially, we further discovered that the optimal catalytic performance is achieved by effectively balancing these two pathways, which requires a moderate metal-PMS adsorption coupled with an extensive and strong hydrogen-bonding network. This work presents the first elucidation of the relationship between multi-channel electron transfer and catalytic activity. The resulting Co-HAB system exhibited remarkable decontamination performance, completely degrading 2,4-dichlorophenol within 30 seconds with an ultrahigh reaction rate constant of 9250 min^-1 mol^-1. Moreover, continuous operation in a membrane flow reactor confirmed the high efficiency and stability of the M-HAB/PMS system in practical water treatment. This work pioneers the hydrogen bond-induced multi-channel electron transfer to intensify PMS activation, establishing a valuable design perspective for high-performance catalysts in advanced oxidation processes.