Elucidating atomic structure and reconstruction of Mn3O4(001) surface

[Display omitted] •Atomic structures of Mn3O4(001)- (√2×√2)R45° and p(2 × 1) superstructures are revealed by STM and DFT.•Surface phase diagram of Mn3O4(001) shows that Mn-rich termination with octahedral Mn pairs is stable in the reductive condition.•The polarity compensation and low surface energy of these termination contribute to its high stability. Understanding the surface structure of oxides is crucial for the design of efficient catalysts and advancing mechanistic research. The intricate surface structures of spinel-like oxides, however, present significant challenges. Herein, we study the atomic structure of Mn3O4(001) surface by a combination of Scan Tunneling Microscopy (STM), X-ray Photoelectron Spectroscopy (XPS) and Density Functional Theory (DFT) approach. We find that Mn3O4(001) surface exhibits a reconstructed Mn-rich termination with two types of superlattices, (2 × 2)R45° and p(2 × 1). A surface unit cell has a Mn6O8 stoichiometry in the topmost layer and Mn1 in the subsurface layer. This reconstructed Mn3O4(001) surface shows stability under reductive conditions. Notably, it resembles the reported Fe-rich Fe3O4(001) surface reconstruction, suggesting common spinel oxides structural elements. These findings not only unveil the detailed surface structure of Mn3O4(001) but also suggest potential universality among spinel oxide surfaces, opening avenues for the design of advanced oxide catalysts.