Characteristics and catalytic properties of the nano-Pd/SiO2 catalysts synthesized in one-step flame spray pyrolysis (FSP) were compared to those prepared on the flame-made SiO2 supports by conventional impregnation method. Pd-0 metal particles/clusters <3 nm in size were obtained directly from a single-step flame process, whereas the conventional impregnation method resulted in PdO with larger crystallite sizes (in the range of 5-12 nm). Although there was little difference in the turnover frequency (TOF) values for 1-heptyne hydrogenation on the different Pd/SiO2 catalysts prepared by impregnation, the TOF values of the flame-made catalysts decreased from 66.2 s(-1) to 4.3 s(-1) as the palladium loading increased from 0.5 wt % to 10 wt %, which suggested changes in the catalytic properties when palladium nanoparticles were formed simultaneously in the support matrices by FSP method. For both preparation methods, the palladium particle sizes remained unaltered after liquid-phase hydrogenation reaction.