Гідрогеноліз ксилози до С2-С3 діолів на Cu-Cr2O3/Al2O3 каталізаторі

This study is dedicated to the continuous-flow hydrogenolysis of xylose 10 wt. % solutions in a methanol-water mixture to produce ethylene glycol and propylene glycol over Cu-Cr2O3/Al2O3 catalyst. A series of catalyst samples with varying CuO loadings (13–19 wt. %) were synthesized...

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Datum:2025
Hauptverfasser: Horbaniuk, I.S., Trachevskiy, V.V., Brei , V.V.
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Veröffentlicht: Chuiko Institute of Surface Chemistry National Academy of Sciences of Ukraine 2025
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Online Zugang:https://www.cpts.com.ua/index.php/cpts/article/view/830
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Назва журналу:Chemistry, Physics and Technology of Surface

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Chemistry, Physics and Technology of Surface
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Zusammenfassung:This study is dedicated to the continuous-flow hydrogenolysis of xylose 10 wt. % solutions in a methanol-water mixture to produce ethylene glycol and propylene glycol over Cu-Cr2O3/Al2O3 catalyst. A series of catalyst samples with varying CuO loadings (13–19 wt. %) were synthesized through wet impregnation of ?-Al2O3 support followed by heat treatment at 350 °C for 4 hours and later reduction of CuO by H2 to metallic copper. Complete reduction of CuO to metallic copper was confirmed by X-ray diffraction analysis of samples. To investigate the acid-base characteristics of obtained catalysts, desorption mass spectrometry was used. Catalytic experiments were conducted in a stainless steel flow reactor with a fixed catalyst bed (4 cm3, ~2.3 g) under conditions of 180 °C, 4.0 MPa H2 pressure, and a catalyst load of 1.6 mmol C5H10O5/gcat/h. According to product analysis using 13C NMR spectroscopy and gas chromatography, propylene glycol and ethylene glycol as main products, along with minor amounts of xylitol, glycerol, hydroxyacetone, and other by-products were identified. The 19Cu-Cr2O3/Al2O3 catalyst provides complete xylose conversion with productivities of 1.0 mmol/gcat/h for propylene glycol and 0.7 mmol/gcat/h for ethylene glycol. Lowering Cu content in Cu-Cr?O?/Al?O? catalyst resulted in decreasing its productivity. At 13 % Cu content, undesirable hydroxyacetone was observed. Noted, the catalyst exhibited consistent activity for 15 h in the methanol-water system, significantly exceeding the 8 h stability observed in 10 wt. % aqueous xylose solutions. This enhanced stability is attributed to improved hydrogen solubility and effective dissolution of intermediate products in the methanol-water mixture that prevents catalyst deactivation.