Microwave-hydrothermal synthesis of mesoporous gamma-Al2O3 and its impregnation with AgNPs for excellent catalytic oxidation of CO

Mesoporous.-alumina was synthesized by the microwave-hydrothermal process with a shorter duration time at 150. C/2 h followed by calcination at 550. C/1 h. Ag nanoparticles (AgNPs) were impregnated into.-alumina under a reducing atmosphere at 450. C. The synthesized product was characterized by X-ray diffraction (XRD), thermogravimetric (TG)/differential thermal analysis (DTA), X-ray photoelectron spectroscopy (XPS), N2 adsorption-desorption study, fieldemission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The BET surface area values of.-alumina and Ag-impregnated.-alumina were found to be 258 and 230 m2 g-1, respectively. FESEM images showed the formation of grain-like particles of 50-70 nm in size with a flake-like microstructure. The XRD, XPS and TEM studies confirmed the presence of Ag in the synthesized product. Catalytic properties of the product for CO oxidation was studied with the T50 (50% conversion) and T100 (100% conversion) values of 118 and 135. C, respectively; the enhanced values were compared with the literature reported values.