Preparation and Characterization of Eggshell-shaped CuO/ZnO/SiO2 Particulate Catalysts Modified with Ce
Ce掺杂的蛋壳型CuO/ZnO/SiO2颗粒催化剂的制备和表征

Eggshell-shaped CuO/ZnO/SiO2 and CuO/ZnO/Ce/SiO2 particulate catalysts supported with porous hollow SiO2 nanoparticles were prepared by a two-step precipitation method combined with addition of surfactant. The catalytic performances of the prepared catalysts for methanol synthesis from CO hydrogenation were investigated, and the catalyst structure was characterized by TEM, BET, XRD and XPS techniques. The results showed that the catalysts supported with porous hollow SiO2 nanoparticles had large specific surface areas, and the CuO and ZnO particles with an average size of about 13 nm were well dispersed on the support. The Ce promoter could improve the catalytic activity and the selectivity of methanol significantly, probably by two reasons: (1) Ce could lower the binding energy of Cu 2p3/2 and Zn 2p3/2, thus facilitating the reduction of CuO to Cu by hydrogen, and (2) the presence of Ce might enhance the interaction between Cu and Zn, and hence improved the dispersion of active components by preventing Cu particles from aggregating.