Lewis base sites of non-oxide supports boost oxygen absorption and activation over supported Pt catalysts

Abstract

Formaldehyde (HCHO) oxidation to improve indoor air quality has attracted extensive attention. Designing efficient catalysts for HCHO removal at room temperature still remains challenging. Herein, we report a novel strategy to boost HCHO oxidation by the synergistic effect of Pt nanoparticles and C₃N₄. The pyridine nitrogen of C₃N₄ can create Lewis base sites, which function in adsorbing and activating O₂ molecules. As the preparation temperature increased, the pyridine nitrogen content increased on the C₃N₄ surface, leading to a more significant synergistic effect. The mechanism study by in situ DRIFTS indicated that the adsorbed O₂ molecules were activated by Pt/C₃N₄. As a result, the Pt/C₃N₄-650 has the most outstanding performance for HCHO oxidation at room temperature. HCHO can be completely eliminated with a concentration of 80 ppm at room temperature at a GHSV of 50 000 ml g⁻¹ h⁻¹. This study will provide a new perspective to design efficient HCHO oxidation catalysts.