Preparation, characterisation and catalytic activity of gold nanoparticles supported on Co3O4

Gold nanoparticles supported on Co3O4 (Au:Co3O4 = 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 Co3O4 has grain sizes in the range of 7–20 nm. The specific surface area was determined by Brunauer–Emmett–Teller method (BET) as 69 m²/g. The studies of catalytic properties showed that the total conversion temperature (T100) for CO and C3H6 oxidation was relatively low at 27°C and 200°C, respectively. The catalyst having high activity for CO oxidation at ambient temperature could be a good candidate for environment treatment.