esterification of levulinic acid to ethyl levulinate biodiesel catalyzed by highly active hierarchically structured ti-beta zeolite

The nanosized ti-containing zeolite beta has been prepared by a two-step post-synthesis approach, which consists of creating vacant t sites with associated silanol groups by dealumination of h-beta and subsequent titanation of the resulting si-beta with titanium isopropoxide. the samples were characterized by x-ray powder diffraction, n2 adsorption–desorption isotherms, field emission scanning electron microscopy, and fourier transform infrared spectroscopy. the hierarchically structured ti-beta zeolite, with a significant mesopore volume (vmeso = 0.39 cm³/g) and large surface area (513 m2/g), and without loss of microporosity and crystallinity, was found to play a crucial role in liquid phase esterification of levulinic acid with ethanol.