International Journal of Hydrogen Energy, Vol.33, No.22, 6657-6666, 2008
Production of hydrogen by aqueous-phase reforming of glycerol
The activities and stabilities of Pt, Ni, Co, and Cu catalysts for H(2) production by aqueous-phase reforming of glycerol, as well as the effect of support on activity and stability, were studied using a fixed-bed flow reactor. Both of the fresh and spent catalysts were characterized by XRD, N(2) adsorption/desorption, TPO, H(2)-TPR, and H(2) chemisorption. It was found that the activity of the metal catalysts increased in the order of Co, Ni, Cu. and Pt. Additionally, Pt was highly stable, whereas Ni and Cc showed significant deactivation with time on stream. It was also found that the activity of supported Pt catalysts was given as follows: SAPO-11 < AC(active carbon) < HUSY < SiO(2) < MgO < Al(2)O(3). Moreover, basic support resulted in high activity and higher hydrogen molar concentration, whereas acidic support and neutral Al(2)O(3) support tended to increase alkane formation. It was shown by XRD that Pt was caused to sinter on all of the supported Pt catalysts during the reaction. In addition, trace amount of carbon deposition was found on all of the supported Pt catalysts. However, no remarkable deactivation was observed over Pt/Al(2)O(3), Pt/SiO(2), Pt/AC, and Pt/HUSY catalysts. Noteworthy was the investigation of the two zeolite-supported catalysts. However, low activities as well as the collapse of the support were obtained. In addition, little influence of the collapse of the support on the stability of Pt/HUSY was observed, whereas Pt/SAPO-11 exhibited remarkable deactivation. (C) 2008 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.