Kinetic modeling of low temperature oxidation of copper nanoparticles by O2

•Low temperature oxidation of copper nanoparticles resulted in hollow Cu2O particles.•A mechanism is proposed to explain the outward growth of Cu2O.•The reaction involves simultaneously growth and nucleation processes of Cu2O.•Adsorption is the rate determining step below the slowdown of the reaction.•A kinetic model is proposed and confronted to the experimental data.

The mechanism and kinetics of copper nanoparticles oxidation at low temperature were investigated using thermogravimetry (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD) and transmission electron microscopy (TEM). Isothermal and isobaric studies of the oxidation reaction were carried out at various temperatures. It was found that working under an oxygen partial pressure of 1 kPa in the temperature range 125–145 °C leads to reaction where nucleation of the oxide phase is in competition with its growth. The study of the dependency of the growth rate on the oxygen partial pressure under 10 kPa has shown the adsorption of oxygen at the surface of the oxide to be the rate-determining step. A mechanism and a kinetic model have been established to interpret the experimental curves.