Heterogeneous oligomerization of ethylene over highly active and stable Ni-AlSBA-15 mesoporous catalysts

• Published in: Journal of catalysis Vol. 323; pp. 76 - 84
• Main Authors: Andrei, Radu Dorin, Popa, Marcel Ionel, Fajula, François, Hulea, Vasile
• Format: Journal Article
• Language: English
• Published: San Diego Elsevier Inc 01.03.2015; Elsevier BV; Elsevier
• Subjects: AlSBA-15; aluminum; Catalysis; Catalysts; catalytic activity; Chemical Sciences; Chemical synthesis; cracking; Ethylene; ion exchange; Nickel; nuclear magnetic resonance spectroscopy; Oligomerization; Porous materials; porous media; Post-synthesis alumination; silica; sodium; sorption; stable isotopes; transmission electron microscopy; Nickel; Oligomerization; AlSBA-15; Post-synthesis alumination; Ethylene
• ISSN: 0021-9517; 1090-2694
• DOI: 10.1016/j.jcat.2014.12.027

[Display omitted] •Ni-AlSBA-15 was prepared by post-synthesis alumination and ion exchange.•Ni-AlSBA-15 was used as catalyst in the ethylene oligomerization.•The catalytic performances were superior than those exhibited by other Ni-based catalysts.•A mechanism involving metallacyclic intermediates is supported by the experimental results. Ni-AlSBA-15 oligomerization catalysts (2.6wt% Ni, Si/Al=7) were prepared by post-synthesis alumination of SBA-15 silica with sodium aluminate, followed by ion exchange with nickel. Characterization techniques, including powder X-ray diffraction, N2 sorption, TEM, 27Al, and 29Si MAS NMR proved the perfect pore system of the SBA-15 materials, with aluminum tetrahedrally mainly coordinated in the silica framework. Ni-AlSBA-15 exhibited outstanding catalytic behavior in the oligomerization reaction of ethylene. At 150°C and 3.5MPa, in both batch and flow mode, the catalyst was highly active (up to 175g of oligomers per gram of catalyst per hour), selective (C4, C6, C8, and C10 olefins, no cracking products), and stable (high conversion during 80h on stream). These performances were superior than those exhibited by other Ni-based heterogeneous catalysts, without using alkylaluminum cocatalysts. A mechanistic pathway involving metallacyclic intermediates is supported by the experimental results.