ELSEVIER Applied Catalysis A: General 132 ( 1995) 77-96 n-Hexane and n-heptane isomerization at atmospheric and medium pressure on Moo,-carbon- modified supported on SIC and yA1,0, Cuong Pham-Huu ‘, Pascal Del Gallo a, Eric Peschiera b, Marc J. Ledoux ‘,* ’ Laboratoire de Chimie des Mate’rinux Cntulytiquex Ecoles de.7 Hautes Etudes des Industries Chimiques de Strasbourg, UrriversitP Louis Pasteur. I, rue Blaise Pmcul, 67008. Strasbourg Cedex, France h Groupe des MatPriuu.u Inorganiques, IPCMS-EHICS, UMR 36 du CNRS, Ecoles des Hnutes Etudes des lndusrries Chimiques de Stmsbourg. 23. rue du Loess, 67037, Strasbourg Cedex, France Received 3 April 199.5: revised 23 June 1995: accepted 23 June 1995 Abstract Catalytically active molybdenum oxycarbide has been successfully prepared on an efficient carrier, Sic. Comparisons with the conventional alumina support show that the strong interaction between MOO,, the starting material, and A120,, partially blocks the formation of the oxycarbide; the active phase can only be prepared at very high loading. X-ray diffraction and temperature-programmed reduction are used to follow the different types of interaction between the precursor, the carrier and the active phase. Isomerization tests of n-C, and n-C, at various pressures confirm that the SIC supported catalyst does not lose its very interesting properties in terms of selectivity versus activity previously found for the bulk materials. Keyord.~: Molybdenum oxycarbide: Hexane isomerization; Heptane isomerization 1. Introduction In the chemical and petrochemical industries crude oil plays a crucial role as a raw material and catalysts are important in the processing of this oil. Among these processes, isomerization is an important reaction which allows the transformation of low octane straight chain alkanes, which are a major constituent in some crude oil fractions, into high octane branched molecules. Furthermore, the aromatization of the alkanes must be avoided due to new regulations requiring the reduction of * Corresponding author. E-mail 1edouxQcoumot.wstrasbg.fr, fax. ( + 33) 88613766 0926-860X/95/$09.50 0 1995 Elsevier Science B.V. All rights reserved SSD/O926-860X(95)00151-3