(560au) Aqueous Phase Reforming of Ethanol over Nickel Supported on Oxygen Ion Conducting Supports

Aqueous phase reforming of ethanol was carried out over nickel catalysts supported on yttrium-stabilized zirconium (YSZ), gadolinium-doped ceria (GDC), and samarium-doped ceria (SDC), which are materials which show high oxygen ion conductivity (OIC) and contrasted to an alumina support. Those supports that with a high OIC demonstrate superior ethanol conversion and hydrogen production compared to the non-conducting support. In previous work, it was found that ceria was superior to alumina as a support. Ceria has a higher OIC than alumina though other factors will affect the activity. In other experiments, OIC supports have been shown to enhance the water-gas shift reaction as well as carbon burnoff. This work will determine how the OIC supports enhance catalytic activity.

Preliminary results from thermogravimetric analysis of used (12 hours) catalysts shows that the GDC support actually leads to the most carbon formed despite the high activity. It is known that the type of carbon formed plays an important role in deactivation. Further results with longer time-on-stream experiments that determine the amount and type of carbon formed will be carried out. Furthermore, the catalyst particle size is known to have an effect on carbon formation, so results from TEM and chemisorption will be presented. The overall goal is to unravel the relationship between support material, carbon formation, and nickel particle size to explain the observed reactor results and determine how important the role of OIC is in the aqueous phase reforming of ethanol.