Facilely Fabricated Single-Site Pt δ+ -O(OH) x - Species Associated with Alkali on Zirconia Exhibiting Superior Catalytic Oxidation Reactivity.

Fabrication of robust isolated atom catalysts has been a research hotspot in the environment catalysis field for the removal of various contaminants, but there are still challenges in improving the reactivity and stability. Herein, through facile doping alkali metals in Pt catalyst on zirconia (Pt-Na/ZrO 2 ), the atomically dispersed Pt δ+ -O(OH) x - associated with alkali metal via oxygen bridge was successfully fabricated. This novel catalyst presented remarkably higher CO and hydrocarbon (HCs: C 3 H 8 , C 7 H 8 , C 3 H 6 , and CH 4 ) oxidation activity than its counterpart (Pt/ZrO 2 ). Systematically direct and solid evidence from experiments and density functional theory calculations demonstrated that the fabricated electron-rich Pt δ+ -O(OH) x - related to Na species rather than the original Pt δ+ -O(OH) x -, serving as the catalytically active species, can readily react with CO adsorbed on Pt δ+ to produce CO 2 with significantly decreasing energy barrier in the rate-determining step from 1.97 to 0.93 eV. Additionally, owing to the strongly adsorbed and activated water by Na species, those fabricated single-site Pt δ+ -O(OH) x - linked by Na species could be easily regenerated during the oxidation reaction, thus considerably boosting its oxidation reactivity and durability. Such facile construction of the alkali ion-linked active hydroxyl group was also realized by Li and K modification which could guide to the design of efficient catalysts for the removal of CO and HCs from industrial exhaust.