High-pressure temperature-programmed reduction of sulfided catalysts

Temperature-programmed reduction (TPR) of solids materials is a widely used technique of characterization in heterogeneous catalysis, So far all studies dealing with this technique have been carried out at ambient or subambient pressure. Because most catalytic processes are performed at higher hydrogen pressures, the impact of this technique could be enhanced by the development of a new generation of equipment working under conditions approaching those used in reality, This work describes a new experimental temperature-programmed reduction set-up working at hydrogen pressures above 1 atm, Basic hydrodynamic considerations have been employed for correcting the signal from the variations of the residence time distribution of the molecules in the reactor. Model and industrial sulfide catalysts were studied at various pressures, When the raw signals are suitably corrected, it appears that the hydrogen pressure does not influence the TPR patterns. (C) 1997 Academic Press.