Effects of Alkali and Counter Ions in Sn-Beta Catalyzed Carbohydrate Conversion
| Autor: | Elliot, Samuel G., Tolborg, Søren, Madsen, Robert, Taarning, Esben, Meier, Sebastian |
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| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Zdroj: | Elliot, S G, Tolborg, S, Madsen, R, Taarning, E & Meier, S 2018, ' Effects of Alkali and Counter Ions in Sn-Beta Catalyzed Carbohydrate Conversion ', ChemSusChem , vol. 11, no. 7, pp. 1198-1203 . https://doi.org/10.1002/cssc.201702413 |
| Popis: | Alkali ions have been shown to strongly influence the catalytic behavior of stannosilicates in the conversion of carbohydrates. An effect of having alkali ions present is a pronounced increase in selectivity towards methyl lactate. Mechanistic details of this effect have remained obscure and are herein addressed experimentally through kinetic experiments and isotope tracking. Alkali ions have a differential effect in competing reaction pathways: they promote the rate of carbon-carbon bond breakage of carbohydrate substrates, but decrease the rates of competing dehydration pathways. Further addition of alkali inhibits activity of Sn-Beta in all major reaction pathways. The alkali effects on product distributions and on rates of product formation are similar, thus pointing to a kinetic reaction control and to irreversible reaction steps in the main pathways. Additionally, an effect of the accompanying basic anions is shown, supposedly facilitating the cation exchange and eliciting a different concentration-dependent effect than neutral alkali salts. |
| Databáze: | OpenAIRE |
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