Journal of Power Sources, Vol.325, 51-63, 2016
Routes for deactivation of different autothermal reforming catalysts
Fuel cell systems with integrated autothermal reforming units require active and robust catalysts for H-2 production. In pursuit of this, an experimental screening of catalysts utilized in the autothermal reforming of commercial diesel fuels is performed. The catalysts incorporate a monolithic cordierite substrate, an oxide support (gamma-Al2O3, La-Al2O3, CeO2, Gd-CeO2, ZrO2, Y-ZrO2) and Rh as the active phase. Experiments are run by widely varying the O-2/C and H2O/C molar ratios at different gas hourly space velocities. In most cases, this provokes accelerated catalyst deactivation and permits an informative comparison of the catalysts. Fresh and aged catalysts are characterized by temperature-programmed methods, thermogravimetry and transmission electron microscopy to find correlations with catalytic activity and stability. Using this approach, routes for catalyst deactivation are identified, together with causes of different catalytic activities. Suitable reaction conditions can be derived from our results for the operation of reactors for autothermal reforming at steady-state and under transient reaction conditions, which helps improve the efficiency and the stability of fuel cell systems. (C) 2016 Elsevier B.V. All rights reserved.
Keywords:Catalyst activity;Catalyst characterization;Catalyst deactivation;Autothermal reforming;Commercial diesel fuel;Fuel cells