Study of copper nanoparticles formation on supports of different nature by UV–Vis diffuse reflectance spectroscopy

Supported copper particles are widely used in heterogeneous catalysis. Influence of supports of different nature on the Cu particles formation is studied by the methods of UV–Vis spectroscopy of diffuse reflectance, XRD and electron microscopy. Different states of supported copper have been identified by UV–Vis spectroscopy: absorption bands at 250 (Cu+), 320–370 and 400–440 (charge transfer bands of O–Cu–O and Cu–O–Cu complexes), 520–580 (Cun plasmon resonance) and 620–850 nm (d–d transitions in Cu2+ ions). The size of Cu clusters and Cun/Cunδ+ ratio strongly depends on the support nature.