Abstract

OBERTO, Tania et al. Alkylation of benzene with 1-dodecene catalyzed by modified claysAlquilación de benceno con 1-dodeceno catalizada por arcillas modificadas. Rev. Téc. Ing. Univ. Zulia [online]. 2007, vol.30, n.2, pp.143-150. ISSN 0254-0770.

A natural smectite clay (STx-1, USA), was ion-exchanged with Al, Cr and Fe or pillared with the same cations. Samples combining these two treatments were also obtained. The prepared solids were characterized by X-ray fluorescence diffraction (XRF), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and N₂ adsorption. The catalytic activity was evaluated by using the alkylation of benzene with 1-dodecene. XRF results showed an increase in the metal content, giving evidence that the metal was effectively exchanged or deposited over the starting material. Al- and Fe-pillared clays showed a significant increase of the surface area, but this was not observed for the Cr-pillared one. Ion exchanged clays showed similar surface areas to that of the starting clay. From XRD results, only the Al-pillared clay gave an increase of the d-spacing. All catalysts showed low conversions towards the product of interest, and this is perhaps attributed to lack of molecular accessibility in the clay gallery or that there are no strong acid sites able to catalyze the alkylation, but strong enough to induce 1-dodecene isomerization. Moderate conversions were observed (27% for the most active catalyst, Cr/ST-P-Al)

Keywords : Alkylation; clays; ion-exchanged; pillared clays.