Facile and High-Yield Synthesis of Alkyl Levulinate Directly from Furfural by Combining Zr-MCM-41 and Amberlyst-15 without External H2

An integrated multistep catalytic process in a one-pot cascade model to realize conversion is preferred in terms of process economics and energy efficiency. Here, we present the noble-metal-free but highly effective catalytic transfer hydrogenation and acid-catalyzed conversion of biomass-derived furfural for direct production of biofuel alkyl levulinate using alcohols as the hydrogen donor and reaction medium. With optimization of the process variables, a high yield of alkyl levulinate at up to 85.3% could be captured under mild conditions in isopropanol medium with the combination of Zr-MCM-41 and Amberlyst-15 catalysts. The reaction proceeds via the catalytic transfer hydrogenation of furfural to furfuryl alcohol over Zr-MCM-41, which is then converted to alkyl levulinate by an Amberlyst-15 acid catalyst. The spent hybrid catalysts could be effectively recovered from the resulting reaction mixture and reused 5 times with little deactivation after plain regeneration treatment.