Dehydrogenation of ethylbenzene to styrene using Pt, Mo, and Pt-Mo catalysts supported on clay nanocomposites

A synthetic clay (TS-1) was modified with a nonionic surfactant (IGEPAL CO-720) and magnesium oxide. The resulting solid was used as a support of Pt, Mo, and Pt-Mo catalysts. The catalysts were prepared by wet impregnation with aqueous solutions of H2PtCl6 center dot 6H(2)O and (NH4)6-Mo7O24 center dot 4H(2)O. In both monometallic and bimetallic catalysts, the molybdenum content was 3 wt% and the platinum content was 0.5 or I wt%. The surface area of the starting material was 454 m(2)/g and after the modification treatment with IGEPAL it increased up to 649 m2/g, while platinum and molybdenum catalysts showed surface areas between 495 and 550 m2/g. The reduction profiles showed different Pt and Mo species and the existence of metal-support interactions. The reduced catalysts were more active than those in the unreduced form. The most active catalysts for the ethylbenzene dehydrogenation were those of monometallic Pt (0.5 and I wt%) with a maximum styrene conversion around 50%. The presence of Mo species masked Pt atoms and reduced the activity. (c) 2007 Elsevier Inc. All rights reserved.