One step synthesis of Mo-doped carbon microspheres for valorization corncob to levulinic acid

Abstract

This work presents the catalytic valorization agricultural waste into levulinic acid over Mo-doped carbon microspheres (MoCMP) in γ-valerolactone/water solvents. The MoCMP with Brønsted and Lewis acid were synthesized by hydrothermal carbonization of uncrystallized cellulose with phosphomolybdic acid in one step, which was in absence of any additional modification. The MoCMP catalyst displayed a peak levulinic acid yield of 33.02% at 195 ℃ for 90 min. The improvement of Lewis acid sites was related by the Mo2C and Mo6+ species to promote the isomerization of glucose to fructose. The enhanced strong Brønsted acid sites were generated by carboxyl groups to facilitate the glucose dehydration to levulinic acid. MoCMP provided a high catalytic efficiency for production of LA from corncob. A simple and green method was proposed to synthesize Mo-doped carbon microspheres for valorization of agricultural biomass into valuable chemicals.