Regulating the Pt-MnO 2 Interaction and Interface for Room Temperature Formaldehyde Oxidation.

Formaldehyde (HCHO) is a hazardous pollutant in indoor space for humans because of its carcinogenicity. Removing the pollutant by MnO 2 -based catalysts is of great interest because of their high oxidation performance at room temperature. In this work, we regulate the Pt-MnO 2 (MnO 2 = manganese oxide) interaction and interface by embedding Pt in MnO 2 (Pt-in-MnO 2 ) and by dispersing Pt on MnO 2 (Pt-on-MnO 2 ) for HCHO oxidation over Pt-MnO 2 catalysts with trace Pt loading of 0.01 wt %. In comparison to the Pt-in-MnO 2 catalyst, the Pt-on-MnO 2 catalyst has a higher Brunauer-Emmett-Teller surface area, a more active lattice oxygen, more oxygen vacancy activating more dioxygen molecules, more exposed Pt atoms, and noninternal diffusion of mass transfer, which contribute to the higher HCHO oxidation performance. The HCHO oxidation performance is stable over the Pt-MnO 2 catalysts under high space velocity and high moisture humidity conditions, showing great potential for practical applications. This work demonstrates a more effective Pt-dispersed MnO 2 catalyst than Pt-embedded MnO 2 catalyst for HCHO oxidation, providing universally important guidance for metal-support interaction and interface regulation for oxidation reactions.