Enhanced Performance of NaOH-Modified Pt/TiO2 toward Room Temperature Selective Oxidation of Formaldehyde

Pt/TiO2 catalysts with various Pt loadings (0.05–2 wt %) were prepared by a combined NaOH-assisted impregnation of titania with Pt precursor and NaBH4-reduction. The thermal catalytic activity was evaluated toward catalytic decomposition of formaldehyde (HCHO) vapor in the presence of toluene under ambient conditions. HCHO could be selectively oxidized into CO2 and H2O over Pt/TiO2 catalysts and toluene had no change. Pt/TiO2 catalysts prepared with the assistance of NaOH showed higher HCHO oxidation activity than those without NaOH due to the introduction of additional surface hydroxyl groups, the enhanced adsorption capacity toward HCHO, and larger mesopores and macropores facilitating diffusion and transport of reactants and products. The as-prepared Pt/TiO2 catalysts with an optimal Pt loading of 1 wt % exhibited high catalytic stability. Considering the versatile combination of noble-metal nanoparticles and supports, this work will provide new insights to the design of high-performance catalysts for indoor air purification.