Acid Properties of GO and Reduced GO as Determined by Microcalorimetry, FTIR, and Kinetics of Cellulose Hydrolysis-Hydrogenolysis
| Autor: | Amar Dandach, Thi Thu Ha Vu, Marion Eternot, Nadine Essayem, Sarah Kheireddine, Van Chuc Nguyen |
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| Přispěvatelé: | IRCELYON-C'Durable (CDURABLE), Institut de recherches sur la catalyse et l'environnement de Lyon (IRCELYON), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS) |
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Isothermal microcalorimetry
cellulose hydrogenolysis 02 engineering and technology lcsh:Chemical technology 010402 general chemistry 01 natural sciences cellulose hydrolysis reduced graphene oxide Catalysis acidic cesium salt of 12-tungstophosphoric acid law.invention lcsh:Chemistry chemistry.chemical_compound Adsorption Hydrogenolysis law Polymer chemistry Pyridine lcsh:TP1-1185 Physical and Theoretical Chemistry Cellulose chemistry.chemical_classification Graphene [CHIM.CATA]Chemical Sciences/Catalysis 021001 nanoscience & nanotechnology microcalorimetry [SDE.ES]Environmental Sciences/Environmental and Society 0104 chemical sciences Acid strength lcsh:QD1-999 chemistry graphene oxide 0210 nano-technology acidity of GO |
| Zdroj: | CATALYSTS CATALYSTS, 2020, 10 (12), ⟨10.3390/catal10121393⟩ Catalysts Volume 10 Issue 12 Catalysts, Vol 10, Iss 1393, p 1393 (2020) |
| DOI: | 10.3390/catal10121393⟩ |
| Popis: | Graphene oxide addresses increasing interests as a solid acid catalyst working in water for carbohydrate conversion. If there is a general agreement to correlate its unique catalytic performances to its ability to adsorb sugars, the origin of its acidity remains controversial. In this article, we study the acid strength of graphene oxide (GO) prepared by modified Hummers method and that of reduced GO by calorimetry of NH3 adsorption and by FTIR of pyridine adsorption. Very strong acid sites are detected on GO by calorimetry, while reduced graphene oxide (reGO) is not very acidic. The FTIR of pyridine adsorption shows the prevailing presence of Br&empty nsted acid sites and a unique feature, the presence of pyridine coordinated by hydrogen bonds. This exceptionally strong Br&empty nsted acidity is tentatively explained by the presence of graphene domains decorated by hydroxyl, carboxylic, or sulfonated groups within the GO sheet, resulting in a high mobility of the negative charges which makes the proton free and explains its strong acidity. Accordingly, only GO is active and selective for native cellulose hydrolysis, leading to 27% yield in glucose. Finally, we show that sugar alcohols cannot be formed directly from cellulose using GO combined with Pt/re-GO under hydrogen, explained by the reduction of oxygenated functions of GO. The instability of the functional groups of GO in a reducing atmosphere is the weak point of this peculiar solid acid. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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