International Journal of Hydrogen Energy, Vol.32, No.14, 2868-2874, 2007
Steam reforming of n-hexadecane using a Pd/ZrO2 catalyst: Kinetics of catalyst deactivation
A systematic study of catalyst deactivation is required for the development of a coke resistant and sulfur tolerant catalyst for diesel fuel reforming systems to be used in conjunction with the solid oxide fuel cell (SOFC). In the present study, the performance of a Pd-ZrO2 catalyst coated on a metal foil at various steam to carbon ratios (S/C), temperatures (T) and sulfur content (S) of the fuel were investigated for the steam reforming of n-hexadecane using a tubular reactor. Here n-hexadecane is used as the surrogate for diesel fuel. A decrease in time dependent hydrogen yield indicated catalyst deactivation, with the effects of reaction conditions on the rate of deactivation determined through a statistically designed experiment. A first-order kinetic model, with first-order deactivation rate, was used to obtain best fit values for the reaction rate constant (k(0)) and the deactivation rate constant (k(d)) as a function of S/C, temperature and sulfur loading. Palladium-catalyzed steam reforming of n-hexadecane was adequately modeled using first-order kinetics, the reaction rate was enhanced by increased temperatures and S/C ratios, but was decreased by the presence of sulfur. Catalyst deactivation was more rapid in the presence of sulfur, at low S/C ratios, and at lower temperatures. (c) 2007 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.