Thermogravimetric analysis of the iso-butene oligomerization activity of various forms of synthetic mica-montmorillonite

Abstract

The iso-butene oligomerization activity of pure and metal-substituted synthetic mica-montmorillonite (SMM) was studied by simultaneous thermogravimetric-differential thermal analysis (TG-DTA). The incorporation of matrix Ni and ion-exchanged Co, Ni and Zn into SMM increased its iso-butene oligomerization activity while the presence of water in the olefinic feed reduced activity. These findings corresponded to trends found in previous work on high pressure (50 MPa) propene oligomerization over SMM and metal-substituted SMM.

IMPROVED SELECTIVITY TO C8-OLEFINS FOR ISOBUTENE OLIGOMERIZATION ON NIO-W2O3/Al2O3CATALYSTS

“…Therefore, one of the challenges in the oligomerization of butenes, in order to get high-octane gasoline, is the development of catalysts with high selectivity to C 8 -olefins, avoiding the formation of heavier olefinic fractions (C þ 12 ). Among the catalysts reported for this reaction, besides phosphoric acid on silica, we find: Ziegler-Natta-based catalysts (Reffinger and Hoffman, 1990), zeolites (Villegas et al, 2007;Nkosi et al, 1997), benzyl sulfonic acid on silica (Saus and Schmid, 1985), mica montmorillonite (Vogel et al, 1990), titanium oxide (Chellappa et al, 2001;Mantilla et al, 2004), zirconium oxide (Busca et al, 1989;Lewis and Kydd, 1991), and sulfated zirconia (Mantilla et al, 2005). In the present work seeking highly selective catalysts, the oligomerization of isobutene was studied on W 2 O 3 =Al 2 O 3 and NiO-W 2 O 3 =Al 2 O 3 catalysts, since W 2 O 3 has been reported as an oxide showing important acid properties.…”

Propane-Propylene Oligomerization Over Modified Pillared Clay Catalysts

“…And the tetramers of propylene are used in the production of lubricating oil additives. Research on this subject is more common in scientific literature of the last century [6][7][8][9][10]. Paul et al the first reported that oligomerization of C 3 -C 4 olefins on nickel-substituted synthetic mica-montmorillonites (Ni-SMM).…”

Origin of enhanced Brønsted acidity of NiF-modified synthetic mica–montmorillonite clay

“…An alternative interpretation is that Lewis acid sites on exposed defect sites of the clay structures play a role in hydrocarbon conversion. 14 In this work, we employed periodic DFT calculations to investigate the acidity and reactivity of the SMM clay. Two structural models were considered, one involving BAS in the intralayer of SMM generated by exposing the edge defects of the clay platelets and the other one involving zeolite-like BAS due to isomorphous substitution of Si 4+ by Al 3+ within the tetrahedral silicate layer of SMM.…”