MOLECULAR ASPECTS IN SYN-GAS PRODUCTION - THE CO2-REFORMING REACTION CASE

CO2-reforming reactions have been studied in a plug-flow reactor with catalysts containing less than a monolayer of Rh, Ru, or Ir deposited from tetrametallic dodecacarbonyl clusters onto low surface area polycrystalline alpha-Al2O3, MgO, CeO2, La2O3, and TiO2. The catalytic reactions are studied in conditions at which the carbon formation quickly deactivates Ni-based catalysts but does not deactivate noble metal based materials. Diffuse-reflectance-infrared-Fourier-transform (DRIFT) spectroscopy and mass spectrometry experiments inside a high-temperature high-pressure (HTHP) chamber have cast light on molecular aspects of the CO2-reforming reaction which have been embodied in a reaction mechanism. The formation of highly reactive oxidic species from the dissociation of CO2 is showed, and their role in inhibiting the production of large carbon aggregates is discussed. (C) 1995 Academic Press, Inc.