A comparative study of CeO2-La2O3-based Cu catalysts for the production of hydrogen from simulated coal-derived syngas

CeO2-La2O3-based Cu catalysts were investigated for their ability to produce hydrogen from simulated coal-derived syngas via the water-gas shift reaction in the temperature range of 450-600 C CeO2-La2O3-based Cu catalysts exhibited high activity and stability at high temperatures (T> 550 C) with dry-gas hourly space velocity =239 000 ml/h g(cat) and at atmospheric pressure Furthermore the activity of CeO2-La2O3-based Cu catalysts was found to be proportional to the magnitude of Cu% dispersion and Cu metal surface area with the highest Cu% dispersion and Cu surface area appearing at the La/Cu atomic ratio of 27 achieving the highest activity with 78% CO conversion at 550 degrees C and 21 5% CO conversion at 600 C much higher than commercial iron-chromium high temperature shift catalyst with 59% conversion at 450 C Substitution of Ce by Al in CeO2-La2O3-based Cu catalysts decreased catalyst activity and stability in the temperature range 550-600 C indicating that CeO2 plays an important role in maintaining high activity and stability Addition of Ni to CeO2-La2O3-based Cu catalysts improved their activity at 450 C but led to reduced activity at temperature; of 550 degrees C and above The high activity and stability observed may originate from the synergistic effect of the interaction between Cu2+ species and catalyst support as well as the redox behaviour of the catalyst support Crown Copyright 2010 Published by Elsevier B V All rights reserved