Summary:

The water-gas shift reaction is of central importance in the industrial production of hydrogen, ammonia, and other bulk chemicals utilizing syngas. The commercial high-temperature WGS catalysts are usually iron oxide containing 8-14 wt% of Cr2O3. Cr+6 is highly toxic and harmful for human health and environment. Another drawback of Fe-Cr catalysts is low activity, which dictates higher temperature of operation or higher residence time. Using higher temperatures does not result in higher conversions since the reaction is thermodynamically limited. Using higher residence times, on the other hand, requires large reactor volumes and catalyst costs. A novel catalyst formulation developed is Fe-Al based catalysts promoted with transition and rare-earth metals. A modified sol-gel method is used to prepare highly active and chromium-free iron-based catalysts. The catalysts developed in this invention exhibit an increase in hydrogen yield (approximately 30% and 60% at 400 ºC and 250 ºC, respectively) compared to Fe-Cr catalysts.

Potential Applications:

• Adjust H2/CO ratios in fuel cell applications
• Hydrogen production from coal-derived synthesis gas
• Improve hydrogen production efficiencies for hydrocarbon or biomass reforming

Advantages:

• Environmentally friendly, no toxic Cr+6 in catalyst formulations
• Economically friendly, high activities in a wide temperature operation range