Regulating the Pt-MnO2 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 MnO2-based catalysts is of great interest because of their high oxidation performance at room temperature. In this work, we regulate the Pt-MnO2 (MnO2 = manganese oxide) interaction and interface by embedding Pt in MnO2 (Pt-in-MnO2) and by dispersing Pt on MnO2 (Pt-on-MnO2) for HCHO oxidation over Pt-MnO2 catalysts with trace Pt loading of 0.01 wt %. In comparison to the Pt-in-MnO2 catalyst, the Pt-on-MnO2 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-MnO2 catalysts under high space velocity and high moisture humidity conditions, showing great potential for practical applications. This work demonstrates a more effective Pt-dispersed MnO2 catalyst than Pt-embedded MnO2 catalyst for HCHO oxidation, providing universally important guidance for metal-support interaction and interface regulation for oxidation reactions.