tellurium and 5-hydroxymethylfurfural

tellurium has been researched along with 5-hydroxymethylfurfural* in 1 studies

Other Studies

1 other study(ies) available for tellurium and 5-hydroxymethylfurfural

ArticleYear
Structure-properties relationship in the hydronium-containing pyrochlores (H
    Dalton transactions (Cambridge, England : 2003), 2020, Aug-25, Volume: 49, Issue:33

    A series of defect pyrochlores of the composition (H3O)1+pSb1+pTe1-pO6 have been prepared by ion exchange from K-containing pyrochlores K1+pSb1+pTe1-pO6 in sulfuric acid at 280 °C for 24 h. The structural characterization of the hydronium-containing pyrochlores, including the location of the H3O+ units within the three-dimensional framework, was possible from neutron powder diffraction data in undeuterated samples. The crystal structure for all the compounds is defined in the Fd3[combining macron]m space group, and consists of a covalent framework of SbVO6 and TeVIO6 octahedra distributed at random and connected by their vertices with (Sb,Te)-O1-(Sb,Te) angles close to 136°, conforming to large cages where the hydronium species are located off-center. The absence of K+ ions in the ion-exchanged pyrochlores was confirmed by inductively coupled plasma optical emission spectroscopy and scanning electron microscopy coupled with energy dispersive X-ray spectroscopy. The shape and size of the hydronium units evolve along with the series, becoming more compact as the framework covalence and Lewis-basicity decrease upon Sb enrichment of the structure (for greater p values). The amount and lability of the H3O+ species also increase throughout the series, as wanted: a straightforward correlation of the catalytic activity in the fructose dehydration reaction to 5-hydroxymethylfurfural has been observed, reaching conversion rates up to 88.5% of concentrated fructose solution for the p = 0.25 catalyst. Moreover, a pseudo-first-order kinetic mechanism was simulated, and the kinetic constants obtained from diluted and concentrated enhanced reaction systems were determined and compared.

    Topics: Antimony; Catalysis; Dehydration; Fructose; Furaldehyde; Hot Temperature; Isomerism; Molecular Conformation; Niobium; Onium Compounds; Oxides; Powder Diffraction; Tellurium; Time Factors; X-Ray Diffraction

2020