Distinct Role of Surface Hydroxyls in Single-Atom Pt₁/CeO₂ Catalyst for Room-Temperature Formaldehyde Oxidation: Acid–Base Versus Redox

The development of highly efficient catalysts for room-temperature formaldehyde (HCHO) oxidation is of great interest for indoor air purification. In this work, it was found that the single-atom Pt1/CeO2 catalyst exhibits a remarkable activity with complete removal of HCHO even at 288 K. Combining density functional theory calculations and in situ DRIFTS experiments, it was revealed that the active OlatticeH site generated on CeO2 in the vicinity of Pt2+ via steam treatment plays a key role in the oxidation of HCHO to formate and its further oxidation to CO2. Such involvement of hydroxyls is fundamentally different from that of cofeeding water which dissociates on metal oxide and catalyzes the acid–base-related chemistry. This study provides an important implication for the design and synthesis of supported Pt catalysts with atom efficiency for a very important practical application─room-temperature HCHO oxidation.