Preparation and Characterization of AuNP/Al₂O₃ with Bimodal Nanoporous Structure

AuNP (gold nanoparticle) supported by oxide shows a high reactivity for a PROX (preferential oxiation) reaction at low temperature. Au catalysts were usually prepared by conventional methods such as precipitation, impregnation and vapor phase grafting. In this study, we developed a novel method for the preparation of AuNPs supported on a bimodal nanoporous alumina. The AuNPs were prepared in a toluene phase by the modified Brust method. The metal particle size was able to be controlled from 2 to 50 nm via the control of the surfactant concentrations. The resulting materials were characterized by BET, FE-SEM, TEM, and XRD analyses. After calcinations at 700oC, AuNP/Al2O3 catalyst revealed a bimodal nanoporous structure, with the pore sizes of 3.5 and 7 nm, and demonstrated both a high surface area (350 m2/g) and pore volume (0.9 cm3/g).