Influence of the Ce02 support nano-morphology on Gold nanoparticles activity for photooxidation reactions

Herein, it was studied the influence of the Ce02 support morphology on the activity of gold nanoparticles (NPs) for photooxidation reactions, especially benzyl alcohol oxidation and aniline oxidation into azobenzene. The Ce02 was prepared as nanocubes and nanorods, following the synthesis well reported in the literature.1 The nanocubes presented edges with dimension around 30 nm (Fig 1.a,c), while the nanorods around 100 nm of length and 10 nm of width (Fig 1.b,d). The Au NPs were synthesized separately following the method reported by Damato et al ,2 as expected the NPs were obtained as nanospheres with -30 nm of diameter. After, the Au NPs were impregnated over the Ce02 support by incipient wetness impregnation. Samples before and after the Au NPs deposition were fu lly characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-Ray powder diffraction (XRD), UV-Vis and Raman spectroscopy. Preliminary catalytic tests were performed in a glass reactor illuminated by a visible light loaded with 10 mg of sample, 10 ml of H20 , 1 mmol of benzyl alcohol or aniline and pressurized with 8 bar of oxygen. Both samples presented activity for the photooxidation of benzyl alcohol, however, the nanocube samples showed higher conversion, with no significantly difference in the products selectivity, which may be related with the presence of more oxygen vacancies. More experiments are needed to confirm the differences in the samples activity for photooxidation reactions and better understand the influence of the Ce02 support morphology for the photoreactions.