Catalytic transfer hydrogenation of ethyl levulinate to γ-valerolactone over a novel porous Zirconium trimetaphosphate

The synthesis of γ-valerolactone (GVL) from catalytic transfer hydrogenation (CTH) of levulinic acid (LA) and its esters is attracting more and more attention due to its wide application in additive, solvent, and precursor. Herein, a novel Zirconium trimetaphosphate (Zr-TMPA) was successfully synthesized and characterized by Fourier transform infrared, N 2 adsorption-desorption, powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and NH 3 /CO 2 -TPD. The as-synthesized Zr-TMPA was used to catalyze the CTH reaction of EL to GVL using isopropanol as the hydrogen donor and solvent. Experimental results shown that Zr-TMPA could catalyze the CTH reaction and 96.2% GVL yield could be achieved at 160   °C for 8   h. Key to this success was attributed to the acid sites and basic sites of the prepared catalyst (Zr-TMPA). Finally, a possible reaction mechanism was proposed.