Slowing sintering to increase the lifetime of Cu nanoparticles on metal oxide supports

The development of thermally stable nanoparticles is of utmost importance for applications like catalysis. In particular, Cu nanoparticles supported on metal oxides are easily deactivated under thermal treatments at low temperatures by sintering of the Cu nanoparticles. The formation of thermally stable nanoparticles is typically obtained with secondary drawbacks. In this study, an alternative method for avoiding sintering of Cu nanoparticles is proposed. The method is based on the impregnation of dithiol molecules at the metal oxide support before supporting the Cu nanoparticles. The dithiol molecules are able to avoid the Cu nanoparticle diffusion, thus decreasing the coalescence rate. Furthermore, the Cu nanoparticles are not poisoned during thermal treatments. A simple model is proposed and numerically studied to estimate the minimal concentration of dithiol necessary to avoid sintering of the nanoparticles. The method is not complex, and there is no interference on the original Cu nanoparticles properties. It opens possibilities for widening the lifespan of metal nanoparticles supported on metal oxides.