Highly efficient hydrogenation of levulinic acid into γ-valerolactone over modified bifunctional yolk-shell catalyst

The high efficiency production of renewable resources has been widely used in fuel and synthetic chemistry. In this work, a series of novel, efficient Pd@mSiO₂-xCeO₂ bifunctional yolk-shell catalysts have been developed and applied to the preparation of γ-valerolactone by the hydrogenation of levulinic acid. The results showed that CeO₂ can effectively improve the catalytic performance of the catalyst, then achieve 100 % conversion of levulinic acid and 97 % selectivity of γ-valerolactone. The characterization results showed that the addition of CeO₂ regulated the acid sites of the catalyst, promoted the reduction of PdO, thus promoting the formation of more Pd⁰. In addition, the kinetic experiment results showed that the activation energy of the reaction effectively decreased with the addition of CeO₂. Then, the reaction mechanism was studied using Density functional theory (DFT) calculations. Finally, the encapsulation strategy of mesoporous silica shell provided a stable environment for the catalyst and maintains high activity after 5 cycles. The efficient and stable noble metal catalysts developed in this study significantly enhance the yield of biomass-derived γ-valerolactone. Their large-scale application not only supports the green production of biofuels and biodegradable materials but also establishes a material foundation for the generation of renewable energy, thereby contributing to the realization of a low-carbon circular economy.