Controlled synthesis of α-Al2O3 supported Ag particles with tuning catalytic performance

Abstract

Herein, α-Al2O3 supported Ag particles with controllable size distribution are prepared successfully by tuning of the calcination conditions through an impregnation method. The size of Ag particles could be adjusted by changing the calcination time and temperature. The catalyst samples were analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and other characterization methods under different calcination conditions, and the performance differences of their catalytic reduction of p-nitrophenol (4-NP) were investigated by UV-Vis spectroscopy. The results show that the Ag particles with increased particle size can be obtained on the surface of α-Al2O3 support by increasing the calcination time or calcination temperature. The catalytic performance of the samples obtained by increasing the calcination time decreased, while the catalytic performance of the samples obtained by increasing the calcination temperature increased. This may be due to the interaction between Ag particles and the support, which changes the valence state of Ag species. Also the particle size effect acts on the catalyst and affects its catalytic performance together with the change of valence.