Elucidating atomic structure and reconstruction of Mn3O4(001) surface

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(0 0 1) surface by a combination of Scan Tunneling Microscopy (STM), X-ray Photoelectron Spectroscopy (XPS) and Density Functional Theory (DFT) approach. We root find that Mn3O4(001) surface exhibits a reconstructed Mn-rich termination with two types of superlattices, ( 2 root x 2 )R45 degrees and p(2 x 1). A surface unit cell has a Mn6O8 stoichiometry in the topmost layer and Mn1 in the subsurface layer. This reconstructed Mn3O4(0 0 1) surface shows stability under reductive conditions. Notably, it resembles the reported Fe-rich Fe3O4(0 0 1) surface reconstruction, suggesting common spinel oxides structural elements. These findings not only unveil the detailed surface structure of Mn3O4(0 0 1) but also suggest potential universality among spinel oxide surfaces, opening avenues for the design of advanced oxide catalysts.