Pt Nanoparticles Supported on N/Ce-Doped Activated Carbon for the Catalytic Oxidation of Formaldehyde at Room Temperature

The catalysts of Pt nanoparticles associated with N-doped activated carbon (NAC) supports and a CeO₂ promotor were prepared by impregnation and then tested for their performance in the catalytic oxidation of formaldehyde (HCHO) at room temperature. The Pt–CeO₂/NAC catalyst with a loading of 0.7 wt % Pt and 0.8 wt % CeO₂ exhibited a superior HCHO conversion of 100% at temperatures as low as 25 °C. Physicochemical characterization using HRTEM, H₂-TPR, O₂-TPD, XPS, XAFS, DFT, and in situ DRIFTS was performed to study as-prepared samples. The results indicated that N doping greatly enhanced the dispersion of Pt, which had a lower oxidation state (PtO_x, 0 < x < 1) and smaller particle sizes at nanoscale than those without N doping. In addition, owing to the existence of synergy between the Pt and CeO₂, the introduction of cerium oxide on the catalyst resulted in more surface-reactive O, which caused the catalysts to have enhanced redox properties at low temperatures, which brought the best catalytic activity among the studied catalysts. Finally, the structure–activity principle of the catalyst used for the catalytic oxidation of HCHO was also addressed in this article.