Synthesis and Characterization of Worm-shaped Tubular Lanthanum Aluminum Composite Mesoporous Materials

The lanthanum aluminum mesoporous materials were synthesized using sodium dodecyl sulfate as a template agent by ultrasonic hydrothermal method. The resulting samples were characterized by low angle X-ray diffraction (XRD), N2 adsorption-desorption studies, transmission electron microscopy (TEM) and surface morphology analysis (SEM), surface acid (NH3-TPD), reducibility properties (TPR), X-ray energy dispersive spectrometer (EDS) and thermogravimetric analysis (TG/DTG).Al/La composite mesoporous material were synthesized with n(Al) : n(La)70 : 1.0, 80°C of reaction temperature, 20 h of reaction time, 12 h of crystallization time, 650°C of calcination temperature. The specific surface area of the sample is 273.90 m2·g−1, with the average diameter 5.642 nm and pore volume 0.2354 cm3·g−1. The samples have mesoporous structure and its particles are similar to a worm-shaped tubular structure. The influence of calcination temperature on the surface physical and chemical properties of Al/La composited mesoporous materials was examined, and the results showed that the acid strength was increased but the amount of acidic sites is decreased as the calcination temperature increased. It was found that the sample calcined at 650°C had appropriate acid content, acid strength and better reducibility.