Carbon tetrachloride hydrodechlorination with organometallics-based platinum and palladium catalysts on MgO

Hydrodechlorination of carbon tetrachloride was performed at atmospheric pressure over Pd and Pt catalysts supported on various inorganic oxides (Al2O3, MgO, CeO2) and obtained from different organometallic precursors (Pd(acaC)(2), [Pd(C3H5)Cl](2), Pt(acac)(2) and Pt(CH3CN)(2)Cl-2. Generally, Pd-based catalysts show low conversion levels and high selectivity to C-1-C7+ hydrocarbons with a distribution that fits a typical Schulz-Flory mechanism for alkyl polymerization. On the other hand, Pt catalysts show high and stable activity, the major products are CHCl3 and in lesser extent methane. Catalytic performances depend on the stability, under reaction conditions, of the metal phase, that could be related to the nature of chlorine species pre-adsorbed on catalysts. Owning to their superior catalytic performances, the structural modifications of Pt catalysts under reaction conditions were characterized by EXAFS spectroscopy. (C) 2002 Elsevier Science B.V. All rights reserved.