biostudies-literaturePan YNational Natural Science Foundation of China (National Science Foundation of China)8627https://www.ebi.ac.uk/biostudies/studies/S-EPMC12480962biostudies-literatureUnknown16(1)Metal-support interfaces fundamentally govern the catalytic performance of heterogeneous systems through complex interactions. Here, utilizing operando transmission electron microscopy, we uncover a looping metal-support interaction in NiFe-Fe₃O₄ catalysts during the hydrogen oxidation reaction. At the NiFe-Fe₃O₄ interfaces, lattice oxygens react with NiFe-activated H atoms, gradually sacrificing themselves and resulting in dynamically migrating interfaces. Meanwhile, reduced iron atoms migrate to the {111} surface of Fe₃O₄ support and react with oxygen molecules. Consequently, the hydrogen oxidation reaction separates spatially on a single nanoparticle and is intrinsically coupled with the redox reaction of the Fe₃O₄ support through the dynamic migration of metal-support interfaces. Our work provides previously unidentified mechanistic insight into metal-support interactions and underscores the transformative potential of operando methodologies for studying atomic-scale dynamics.Nature communicationsLooping metal-support interaction in heterogeneous catalysts during redox reactions.PMC12480962U21A20328, 52101277, 22105220, and 22209202Liu XSu DPan YZhen SGu LZhou DGe MZhang LZhao JfalseLooping metal-support interaction in heterogeneous catalysts during redox reactions.Metal-support interfaces fundamentally govern the catalytic performance of heterogeneous systems through complex interactions. Here, utilizing operando transmission electron microscopy, we uncover a looping metal-support interaction in NiFe-Fe₃O₄ catalysts during the hydrogen oxidation reaction. At the NiFe-Fe₃O₄ interfaces, lattice oxygens react with NiFe-activated H atoms, gradually sacrificing themselves and resulting in dynamically migrating interfaces. Meanwhile, reduced iron atoms migrate to the {111} surface of Fe₃O₄ support and react with oxygen molecules. Consequently, the hydrogen oxidation reaction separates spatially on a single nanoparticle and is intrinsically coupled with the redox reaction of the Fe₃O₄ support through the dynamic migration of metal-support interfaces. Our work provides previously unidentified mechanistic insight into metal-support interactions and underscores the transformative potential of operando methodologies for studying atomic-scale dynamics.2025-01-01T00:00:00Z2025 Sep2026-06-03T23:27:02.509Z2026-05-03T03:11:22.119ZS-EPMC124809624102277110.1038/s41467-025-63646-1