Preparation of Alkyl Levulinates from Xylose Over Modified Bifunctional Mesoporous Zirconium Phosphate Catalysts, 

M Dookheh, A Najafi Chermahini, M Saraji, Catalysis Letters 152, 2141–2154

Alkyl levulinates (AL), which are important biomass derivatives, have the potential of conversion into different valuable compounds. This study addressed the production of alkyl levulinate from xylose by applying mesoporous zirconium phosphates (AL-MZP-Pr-SO₃H, MZP-Pr-SO₃H), which served as good heterogeneous catalysts. The characterization of these catalysts was done using FT-IR spectroscopy, low and wide-angle XRD, N₂ adsorption–desorption, ICP, TEM, and SEM. Then the impact of a large number of parameters, like the temperature of reaction, the time of reaction, the catalyst amount, and xylose initial amount was probed. The findings revealed that the maximum n-butyl levulinate yield was 82% at the temperature of 170 °C, after 6 h; meanwhile, the maximum ethyl levulinate yield was 49% at 150 °C, after 6 h. The catalysts can be easily separated from the reaction mixture and regenerated by a simple activation step, with the possibility of reusing at least four times without significant reduction in the catalytic activity.

https://link.springer.com/article/10.1007/s10562-021-03792-5