Harnessing frontier Pt d-orbital alignment to break performance limits in single-atom catalysis

Electronic metal-support interaction (EMSI) critically influences the electronic structure and catalytic efficiency of single-atom catalysts (SACs), yet its role in volatile organic compound (VOC) combustion remains underexplored. This study investigates Pt SACs anchored on narrow-bandgap Fe₂O₃ and wide-bandgap CeO₂ to reveal how support bandgap modulates EMSI to enhance benzene oxidation performance. Combining density functional theory (DFT) calculations, atomic-resolution HAADF-STEM imaging, in situ spectroscopy, and kinetic analyses, we find that Fe₂O₃’s narrow bandgap promotes stronger charge transfer, shifting Pt d-band centers upward (−1.29 eV for Pt₁/Fe₂O₃ vs. −2.56 eV for Pt₁/CeO₂). This upward shift, in conjunction with the proximity of the catalyst's unoccupied d-band centroid to the Fermi level (0.89 eV for Pt₁/Fe₂O₃ vs. 2.02 eV for Pt₁/CeO₂), strengthens orbital overlap with benzene π* orbitals, facilitating C–H bond activation while also promoting O₂ dissociation. By contrast, Pt₁/CeO₂’s downshifted d-band and higher-lying unoccupied d-band centroid hinder efficient activation. Pt₁/Fe₂O₃ achieves 90 % benzene conversion at 237 °C, significantly outperforming Pt₁/CeO₂ (T₉₀ > 410 °C). Experimental and theoretical results confirm Pt₁/Fe₂O₃’s superior redox activity, optimized intermediate decomposition, and strong Pt–Fe₂O₃ synergy, highlighting EMSI-driven support design as a critical strategy for high-performance environmental catalysts. These findings advance the rational design of sustainable catalysts for efficient VOC abatement.