An FT-IR and flow reactor study of the Conversion of propane on gamma-Al2O3 in oxygen-containing atmosphere

The conversion of propane in the presence of oxygen over alumina has been s tudied using a fixed bed flow reactor. The interaction of the same catalyst with propane, propene, isopropanol and acetone has also been investigated, with additional gas-phase monitoring, in an FT-IR cell. Alumina looks acti ve in the catalytic conversion of propane to propene, with the production o f CO2, CO, ethylene, methane as the main by-products, depending On the reac tion temperature. Higher hydrocarbons such as butenes, butadiene, benzene a nd toluene are also found. This reactivity is mainly attributed to the weak but not negligible Bronste d acidity of the surface OH's of alumina, possibly activating propane in th e form of isopropoxides and allowing oligomerization of propene. This shows the detrimental effect of the uncovered alumina support in the case of alu mina-supported catalysts for propane oxydehydrogenation and explains the po sitive role of doping with basic neutralizing agents such as potassium. (C) 2000 Elsevier Science B.V. All rights reserved.