Green diesel production over nickel-alumina nanostructured catalysts promoted by zinc
| Autor: | Emmanouil Simianakis, Christos Kordulis, Kyriakos Bourikas, Eleana Kordouli, Mantha Gousi, George D. Panagiotou, Alexis Lycourghiotis, Spyros Ladas |
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| Rok vydání: | 2020 |
| Předmět: |
food.ingredient
Hydrogen Chemistry Sunflower oil Vegetable oil refining chemistry.chemical_element 02 engineering and technology General Chemistry Zinc 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Catalysis 0104 chemical sciences Nickel food 0210 nano-technology Mesoporous material Deoxygenation Nuclear chemistry |
| Zdroj: | Catalysis Today. 355:903-909 |
| ISSN: | 0920-5861 |
| Popis: | Following the one step co-precipitation technique we have synthesized a series of Ni-Zn catalysts supported on alumina. The series involves one non-promoted sample containing 60 wt % Ni and three zinc promoted samples containing 1, 2 and 5 wt % Zn and 59, 58 and 55 wt % Ni, respectively. The specimens were characterized using nitrogen sorption isotherms, H2-TPR, NH3-TPD, XRD, SEM-EDX, TEM and XPS. The catalytic performance of the samples prepared was evaluated in the selective deoxygenation of sunflower oil using a semi-batch reactor (310 °C, 40 bar of hydrogen, hydrogen flow rate equal to 100 mL/min and reactant to catalyst ratio equal to 100 mL/g). The control of the co-precipitation procedure and the direct reduction of dried precipitate resulted to mesoporous nano-structured catalysts with high surface area (247–290 m2 g−1). The non-promoted sample was mainly comprised from NiAl2O4 particles and the promoted ones from Ni-Zn alloys and intermetallic oxo-phases (IMPs) supported on largely amorphous Al2O3 nano-grains. Zinc increased the total yield of alkanes in the diesel range (n-15, n-16, n-17, n-18) though it does not affect the mechanistic scheme of the selective deoxygenation of sunflower oil which is largely realized via decarbonylation/decarboxylation. The promoting action of zinc was attributed to the favoring of the Ni-Zn alloys and IMPs formation. It is more pronounced in the sample with the medium zinc content (58 wt % Ni, 2 wt % Zn, 40 wt % Al2O3) in which an increase of 18% in the total yield of hydrocarbons has been obtained. The maximization of the zinc promoting action in this sample reflects the good compromise between the extent of alloying and surface acidity. |
| Databáze: | OpenAIRE |
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