Nanostructured surface
Glucose transformation into 5-hydroxymethylfurfural over polycationic nanostructured faujasite zeolite catalysts
Patrylak L., Konovalov S., Yakovenko A., Pertko O., Povazhnyi V.
Department of Catalytic Synthesis, V.P Kukhar Institute of Bioorganic Chemistry and Petrochemistry of NAS of Ukraine. Murmanska Str., 1, Kyiv-02094, Ukraine. E-mail: lkpg@ukr.net

The transformation of biomass to variety of chemical substances is one of the most popular research topics nowadays. Waste cellulose hydrolysis leads to the formation of carbohydrates [1]. Hexoses such as glucose/fructose can be transformed into platform substances. Reaction proceeds over acid catalysts. Nanostructured zeolites possess both systems of regular pores/channels and Brønsted/Lewis acidity and thus can be used in transformation of carbohydrates.  Structure of wide-porous zeolites such as faujasite consists of hexagonal prisms and supercages with 12-ring openings which have free diameter of 0.7-0.8 nm. The same is kinetic diameter of glucose molecules. Faujasites in the polycationic forms are known as effective catalyst for isobutane with butenes alkylation [2].
Therefore, the purpose of this work was to study the transformation of glucose into 5-hydroxymethylfurfural (5-HMF) over polycationic faujasite zeolite catalysts. 
The catalysts were synthesized from Na-forms of zeolite X and Y (Si/Al ratio 1.15 and 2.35, JS “Sorbent”, Russia) by means of ion exchange with Ca2+, La3+ and NH4+ and different thermal treatments. The cations content in the samples obtained were near 20NH452La27CaNaY(X) of exchange capacity. The reaction was carried out in stainless steel autoclaves at 160 oC for 4 h. The glucose was previously dissolved in the dimethyl sulfoxide (DMSO) and 10-20 wt % solutions were obtained. Reaction products were analyzed by GC, and then 5-HMF yields (Y5-HMF) were calculated. The Y5-HMF is stated to be higher in the DMSO medium than in aqua one. In the case of 10 % initial glucose concentration, the Y5-HMF over obtained catalysts were 30-40 % and 20-30 % for 20 % solutions. Catalysts efficiency correlates with both fraction of strong acid sites of catalysts and conditions of their synthesis. Conversions of glucose were from 70 to 95-98 %.
The publication contains the results of studies conducted by grant of National Research Foundation of Ukraine project 2020.01/0042.

1.	Chernyshev V., Kravchenko O., Ananikov V. Conversion of plant biomass to furan derivatives and sustainable access to the new generation of polymers, functional materials and fuels // Russ Chem Rev–2017.-86.-P. 357-387.
2.	Patrylak L.K., Bartosh P.I. Mechanism of the alkylation of isobutane by butenes on zeolite catalysts // Theoret Exper Chem– 2003.-39.-P.177–183.