Enhanced Catalytic Ozonation for Eliminating CH₃SH via Graphene-Supported Positively Charged Atomic Pt Undergoing...

Constructing catalysts with electronic metal-support interaction (EMSI) is promising for catalytic reactions. Herein, graphene-supported positively charged (Pt²⁺/Pt⁴⁺) atomically dispersed Pt catalysts (AD-Pt-G) with PtC₃ (x = 1, 2, and 4)-based EMSI coordination structures are achieved for boosting the catalytic ozonation for odorous CH₃SH removal. A CH₃SH removal efficiency of 91.5% can be obtained during catalytic ozonation using optimum 0.5AD-Pt-G within 12 h under a gas hourly space velocity of 60,000 mL h^-1 g^-1, whereas that of pure graphene is 40.4%. Proton transfer reaction time-of-flight mass spectrometry, in situ diffuse reflectance infrared Fourier transform spectroscopy/Raman, and electron spin resonance verify that the PtC₃ coordination structure with atomic Pt²⁺ sites on AD-Pt-G can activate O₂ to generate peroxide species (*O₂) for partial oxidation of CH₃SH during the adsorption period and trigger O₃ into surface atomic oxygen (*O_ad), *O₂, and superoxide radicals (·O₂^-) to accomplish a stable, high-efficiency, and deeper oxidation of CH₃SH during the catalytic ozonation stage. Moreover, the results of XPS and DFT calculation imply the occurrence of Pt²⁺ → Pt⁴⁺ → Pt²⁺ recirculation on PtC₃ for AD-Pt-G to maintain the continuous catalytic ozonation for 12 h, i.e., Pt²⁺ species devote electrons in 5d-orbitals to activate O₃, while Pt⁴⁺ species can be reduced back to Pt²⁺ via capturing electrons from CH₃SH. This study can provide novel insights into the development of atomically dispersed Pt catalysts with a strong EMSI effect to realize excellent catalytic ozonation for air purification.