The effect of Pt loading on the catalytic performance was studied over Pt/f-SiO2 catalyst (Fig. 2). It can be seen that the catalysts with low Pt loading (i.e., 0.05 wt.% and 0.1 wt.%) are inactive for HCHO oxidation at room temperature. A 30% conversion of HCHO can be achieved at 25 C when the Pt loading reaches 0.5 wt.%.For all the Pt/f-SiO2 catalysts with different Pt loadings, increasing.