Study on the synthesis of nanoporous hydrated zirconia applied to hydrothermal conversion of biomass-derived sugars

PIOVANO, FEDERICO A.; ASPROMONTE, SOLEDAD G.; BOIX, ALICIA V.

MICROPOROUS AND MESOPOROUS MATERIALS

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2024 vol. 368

1387-1811

The synthesis of nanoporous hydrated zirconia catalysts was studied for application in the hydrothermal conversion of monosaccharides and biomass sources. The synthesis was carried out by sol-gel method using zirconium n-propoxide and Pluronic P123 as precursor and template, respectively. Different synthesis solvents, water (W), ethanol (E) and isopropanol (I), as well as different template removal methods, in-cluding thermal treatments and solvent refluxing extraction, were investigated. Physicochemical proper-ties were determined by N2 sorption, TEM, XRD, FTIR and potentiometric titration.Catalysts synthesized in alcoholic solvents by refluxing extraction exhibited high surface areas (320-360 m2/g) and pore volumes (0.20-0.43 cm3/g), which comprised large micropores and mesopores, and ob-tained the most outstanding acidic properties. A strong influence of the synthesis solvent on the amount and strength of acid sites was found, following the order I > E > W. This behavior was explained by differ-ent ratios between the basic terminal and acidic bridging Zr-OH bonds formed on hydrated zirconia. In tune with superior acidic and textural properties, promising mass yields towards lactic acid from a glucose, xy-lose and arabinose mixture (34.8 %), glyceraldehyde (83.36 %), starch (17.1 %) and wheat bran (18.3 %), were attained with the catalyst synthesized in isopropanol.