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

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 gcat. 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 2.7, achieving the highest activity with 7.8% CO conversion at 550 °C and 21.5% CO conversion at 600 °C, much higher than commercial iron–chromium high temperature shift catalyst with 5.9% 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 temperatures of 550 °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.