Mesoporous molecular sieves solid superacid as a catalyst for alcoholysis of fructose into methyl levulinate

Methyl levulinate (MLE) is an important biomass-based platform compound, which is the precursor of many chemicals. In this paper, a series of zirconium-containing mesoporous molecular sieve superacid Si-SCZ-x (x was the molar ratio of Zr/Si) was prepared by hydrothermal synthesis and applied in the reaction of fructose conversion to MLE. The results indicated that when the molar ratio of Zr/Si was 1.3, Si-SCZ-1.3 presented the highest catalytic activity. Under the optimum reaction conditions (catalyst dosage of 5 mg mL(-1), reaction temperature of 160.degrees C, reaction time of 90 min), the yield of MLE was 70.42%. Si-SCZ-1.3 had a large specific surface area of 246.41 m(2) g(-1), excellent hydrothermal stability, considerable total acid content and B/L ratio. The recycling catalysts exhibited excellent reusability with little loss of activity after five runs. The reaction path was analyzed in this catalytic system, and the rate-limiting step of the reaction was concluded to be the ring-opening of 5(Methoxymethyl)-2-furaldehyde to form MLE. This study demonstrated the potential of zirconium-containing mesoporous molecular sieve solid superacid (Si-SCZ-1.3) for the production of MLE under mild process conditions.

Automated summary

This paper presents the utilization of zirconium-containing mesoporous molecular sieve superacid (Si-SCZ-x) as a catalyst for the conversion of fructose to methyl levulinate (MLE). The results showed that Si-SCZ-1.3 exhibited the highest catalytic activity with an MLE yield of 70.42% under optimized reaction conditions. Si-SCZ-1.3 possessed a large specific surface area, excellent hydrothermal stability, and good reusability.