Highly dispersed and active supported Pt nanoparticles for gaseous formaldehyde oxidation: Influence of particle size

•Pt nanoparticles with various sizes were synthesized by sodium borohydride reduction.•Pt nanoparticles are highly dispersed and active for HCHO oxidation at room temperature.•The catalysts’ structure and activity are much affected by heating temperature.•The turnover frequencies of Pt nanoparticles present size-dependent effect. A series of Pt/TiO2 catalysts with various Pt particle sizes and chemical properties were facilely synthesized by NaBH4 reduction and heated at different temperatures. They were used to catalytically oxidize gaseous formaldehyde (HCHO) at ambient temperature. The influence of structural nature of Pt NPs on catalytic activity was investigated. The as-prepared Pt NPs are highly dispersed and very active for HCHO oxidation even at room temperature. The maximum Pt dispersion and HCHO removal efficiency reached 73.4% and 81.3%, respectively. The turnover frequencies (TOFs) of Pt NPs present size-dependent effect. The Pt NPs with average size of 10.1nm had the highest TOF of 4.39s−1 for HCHO oxidation.