In order to further clarify the stabilization mechanism of surface SnOx on Pt/C catalysts, we analyze the structural characteristics and reaction mechanism of the catalyst using firstprinciples calculations. According to the XPS and XAS results, the valence state of Sn is lower than +4, so a SnOx structure with oxygen vacancies is constructed. According to the interface structure observed by spherical aberration correction STEM, Sn7O6@Pt(111) with O-Sn/Pt interface structure (Figure ) and Sn7O12@Pt(111) with O-Sn-O/Pt interface structure (Figure ) were constructed. In the Sn7O6@Pt(111) interface structure, Sn and Pt are directly adjacent, and the Sn-Pt atomic plane distance is 2.40 Å; while in the Sn7O12@Pt(111) structure, O and Pt are adjacent, making the Sn-Pt atomic spacing increases to 2.75 Å. This is basically consistent with the spherical aberration correction STEM characterization results (Figure ).