Active Site-Directed Tandem Catalysis on Single Platinum Nanoparticles for Efficient and Stable Oxidation of Formaldehyde at Room Temperature.

The application of tandem catalysis is rarely investigated in degrading organic pollutants in the environment. Herein, a tandem catalyst on single platinum (Pt) nanoparticles (Pt NPs) is prepared for the sequential degradation of formaldehyde (HCHO) to carbon dioxide gas [CO(g)] at room temperature. The synthesis approach includes coating of uniform Pt NPs on SrBiTaO platelets using a photoreduction process, followed by calcination of the sample in the atmosphere to tune partial transformation of Pt atoms to Pt ions in the tandem catalyst. The conversion of HCHO to CO(g) is monitored by in situ Fourier transform infrared spectroscopy, which shows first conversion of HCHO to CO ions onto Pt active sites and subsequently the conversion of CO ions to CO(g) by neighboring Pt species of the catalyst. The later process with Pt species does not allow CO poisoning of the catalyst. The enhanced activity of the prepared tandem catalyst to oxidize HCHO is maintained continuously for 680 min. Comparatively, the catalyst without Pt shows activity for only 40 min. Additionally, the tandem catalyst presented herein performs better than the Pt/titanium dioxide (TiO) catalyst to degrade HCHO. Overall, the tandem catalyst may be applied to degrade organic pollutants efficiently.