Abstract: To address the issues of low gas-liquid mass transfer efficiency, which limits the catalytic hydrogenation of levulinic acid to γ-valerolactone in high-pressure reactors, solutions were explored from two aspects: preparing high-performance catalysts and optimizing high-efficiency reactors.Firstly, a series of PtSn_x/Al₂O₃ fiber catalysts were prepared by impregnation-rapid calcination method using Al₂O₃ fibers as carriers.The obtained catalysts were systematically characterized by X-ray diffraction, transmission electron microscopy-energy dispersive spectroscopy, N₂ adsorption-desorption, X-ray photoelectron spectroscopy, H₂ temperature programmed reduction and other methods. Furthermore, the catalytic performance in the hydrogenation of levulinic acid was investigated and the kinetics of the catalytic reaction were analyzed. The results indicated that a PtSn alloy was formed on the serface of the prepared catalyst support, with uniform distribution.The optimal PtSn_0.5/Al₂O₃ catalyst achieved 99% levulinic acid conversion with >99% selectivity to γ-valerolactone under mild batch conditions (160 °C, 2 MPa of H₂, 1 h). Kinetic studies revealed first-order dependence on H₂ pressure and zero-order on LA concentration, with an apparent activation energy of 55.7 kJ/mol.Secondly, it is preferred to use a micro packed bed reactor instead of a batch reactor to solve the problem of low gas-liquid mass transfer efficiency. The results showed that with the action of PtSn_0.5/Al₂O₃, the space-time yield was significantly improved and the reaction time was shortened, and the catalyst has excellent performance stability in continuous hydrogenation reactions..

Key words: γ-valerolactone, hydrogenation, micro-packed reactor, fiber catalyst