Hf-β zeolites as highly efficient catalysts for the production of 5-hydroxymethylfurfural from cellulose in biphasic system.

In this work, a series of (x)Hf-β zeolite catalysts were prepared by a simple wet impregnation method and used as bifunctional catalysts with Lewis and Brønsted acid sites for synthesizing 5-hydroxymethylfurfural (5-HMF) from cellulose in H ₂ O _(NaCl) -THF biphasic system. Characterization analysis of (x)Hf-β zeolite catalysts with ICP-OES, N ₂ adsorption-desorption isotherm, XRD, FTIR, SEM, NH ₃ -TPD and Py-FTIR indicated that the catalysts possessed favorable pore structure, appropriate acid strength and acidity. A superior 86.3 % cellulose conversion and 53.4 % 5-HMF yield could be obtained at 200 °C for 4 h by using (5 %)Hf-β zeolite as the catalyst. In addition, the catalytic system provided a favorable 5-HMF yield from other carbohydrates, including glucose (85.1 %), sucrose (80.6 %), starch (65.1 %), maltose (65.0 %), dextran (59.9 %), and Moso bamboo (21.9 %). Nevertheless, the recyclability of (5 %)Hf-β zeolite catalyst was unsatisfactory and the 5-HMF yield showed a downtrend from 53.4 % to 24.4 % after 5 cycles. The catalyst has promising potential for converting biomass materials into high-value platform compounds.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
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