Preparation, characterisation and catalytic activity of gold nanoparticles supported on Co_3O_4

摘要

Gold nanoparticles supported on Co_3O_4 (Au:Co_3O_4 = 1:25) were prepared by co-precipitation method. The co-precipitate was studied by using a thermal analysis (Differential Thermal Analysis - DTA and a Differential Thermal Gravimetric Analysis - DTGA). The characterisations of the sample were investigated by using an X-ray Diffraction (XRD), a High-Resolution Transmission Electron Microscope (HRTEM) and a selected area electron diffraction (SAED). The particle size of gold pieces is less than 4.5 nm and more than 85% of the gold particles were smaller than 3.5 nm. The cobalt oxide Co_3O_4 has grain sizes in the range of 7-20 nm. The specific surface area was determined by Brunauer-Emmett-Teller method (BET) as 69 m~2/g. The studies of catalytic properties showed that the total conversion temperature (T_(100)) for CO and C_3H_6 oxidation was relatively low at 27℃ and 200℃, respectively. The catalyst having high activity for CO oxidation at ambient temperature could be a good candidate for environment treatment.