Ni-β-diimine complex heterogenized in delaminated ITQ-2 zeolite as catalytic precursor for ethylene oligomerization
| Autor: | Katia Bernardo-Gusmão, Bruna Pes Nicola, Christian W. Lopes, Enéderson Rossetto, Carlo Marini, Sibele B. C. Pergher |
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| Rok vydání: | 2021 |
| Předmět: |
X-ray absorption spectroscopy
Ethylene chemistry.chemical_element 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Catalysis 0104 chemical sciences Nickel chemistry.chemical_compound Adsorption chemistry Polymer chemistry 0210 nano-technology Mesoporous material Selectivity Zeolite |
| Zdroj: | Catalysis Today. 381:192-199 |
| ISSN: | 0920-5861 |
| Popis: | A heterogenized nickel catalytic precursor was synthesized and applied in ethylene oligomerization catalytic reactions. For this, a β-diimine ligand was covalently anchored to the delaminated ITQ-2 zeolite and the metal complexed. The homogeneous nickel complex was synthesized in order to compare the effect of catalyst heterogenization on the reaction. The synthesized materials were characterized by several techniques, such as 1H NMR, solid-state 29Si CP-MAS-NMR, FTIR, TGA, N2 adsorption, flame atomic absorption spectroscopy, elemental analysis and X-ray absorption spectroscopy (XAS). The heterogenized catalytic precursor showed similar catalytic activity and higher selectivity for the target products to its homogeneous complex counterpart. The higher stability of the nickel centers under oxidative handling conditions was demonstrated by the XAS measurements. It was possible to reuse the catalytic precursor twice in oligomerization reactions despite the loss of catalytic activity ascribed to the presence of an excess of co-catalyst. Notwithstanding, it was demonstrated that Al-containing delaminated zeolites are promising materials for anchoring β-diimine-based catalytic precursors in comparison with mesoporous materials due to their higher acidity, which improves the intrinsic catalytic activity (turnover frequency, TOF) due to the higher nickel electron withdrawing capacity provided by the acidic support. |
| Databáze: | OpenAIRE |
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