(683f) Sulfur Tolerant Doped Fe/Ce Catalysts for the High Temperature Water Gas Shift Reaction – TPR and Mossbauer Spectroscopic Study

Authors: 
Gunugunuri, K. R., University of Cincinnati
Sridhar, M., University of Cincinnati
Boolchand, P., University of Cincinnati
Smirniotis, P., University of Cincinnati


To stabilize the formation of Magnetite phase during the activation and to promote the Fe3+ ↔ Fe2+ redox couple during the water gas shift reaction, in our previous study we introduced a variety of metal ions (M = Cr, Mn, Co, Ni, Cu, Zn, and Ce) into iron oxide (spinel lattice) and screened for effectiveness for a high-temperature water?gas shift reaction. Among the various catalysts tested Fe/Ce and Fe/Cr spinels with an atomic ratio of 10:1 exhibited the highest activity. Between the Fe/Ce and Fe/Cr catalysts, Fe/Ce catalyst exhibits stable and higher activity in the presence of sulfur compared to Fe/Cr catalysts. In the present study, we investigated the effect of foreign metals as a dopant on high temperature water gas shift activity of Fe/Ce catalyst. For this purpose, various metals like Co, Mo, Zr, Hf, and Cr were doped into Fe/Ce catalyst by using ammonia assisted coprecipitation method. The prepared catalysts were characterized by using TPR, Raman Mossbauer spectroscopic techniques and evaluated for WGS reaction in the temperature region of 400-550 oC and at a steam to CO ratio of 1, which the conditions typically used in our membrane reactor. A relatively high space velocity 60,000 h-1 was used in this study. To verify the sulfur tolerance the experiments were also carried out in the presence of H2S. These interesting results will be presented in the presentation.