Synergistic catalysis of cluster and atomic copper induced by copper-silica interface in transfer-hydrogenation

However, the formation of SMSI between metal and inert-support has been so little coverage and remains challenge. In this work, the SMSI effect can be effectively extended to the inert support-metal catalysis system to fabricate a Cu0/Cu-doped SiO2 catalyst with high dispersion and loading (38.5 wt.%) through the interfacial effect of inert silica.

In the catalyst, subnanometric composite of Cu cluster and atomic copper (in the configuration of Cu-O-Si) can be consciously formed on the silica interface, and verified by extended X-ray absorption fine structure (EXAFS), in situ X-ray photoelectron spectroscopy (XPS), and high-angle annular dark field-scanning transmission electron microscopy (HAADF-STEM) characterization. The promoting activity in transfer-hydrogenation by the SMSI effect of Cu-silica interface and the synergistic active roles of cluster and atomic Cu have also been revealed from surface interface structure, catalytic activity, and density functional theory (DFT) theoretical calculation at an atomic level.