Dynamic Restructuring of PtO Surfaces Propelled by the Bismuth-Promoted S^2- Spillover to Resist the SO₂-Poisoning

Sulfur-induced restructuring of active phases has been identified as one of the dominant reasons why the catalysts are quickly deactivated, posing a significant threat on the long-term use under practical reaction conditions. Three typical strategies have been proposed for designing the SO₂-resistant nanocatalysts. Herein, a new strategy is discovered to preserve the clean PtO_x surfaces in SO₂-containing reaction stream, expected to effectively minimize the sulfur-induced deactivation. In situ CO-DRIFTS, FT-IR, Raman, XPS, HAADF-STEM, sulfur content determination, and DFT are employed to confirm the PtO restructuring behaviors propelled by the bismuth-promoted S^2- spillover effect. In situ SO₂-DRIFTS and theoretical calculation results reveal that the adsorption and dissociation of SO₂ on the PtO_x surfaces are significantly inhibited once the PtO-Bi₂S₃ interfaces are formed by migrating the adsorbed S^2- species to the surfaces of Bi₂O₃. The bismuth-induced dynamic restructuring of PtO surfaces allows to dramatically decrease the activity loss for catalytic CO oxidation and maintain the intrinsic activity following the formate pathway during the introduction of SO₂ molecules. These findings provide a new strategy to design the SO₂-resistant nanocatalysts.