XANES investigation of Mn-promoted Fe-based Fischer-Tropsch catalysts

FUEL 203

Andrew Campos, acampo2@lsu.edu1, Nattaporn Lohitharn, nlohith@clemson.edu2, James J. Spivey, jjspivey@lsu.edu1, Amitava D. Roy, reroy@lsu.edu3, Edgar Lotero, alegria@clemson.edu2, and James G. Goodwin Jr., james.goodwin@ces.clemson.edu2. (1) Dept. of Chemical Engineering, Louisiana State University, S. Stadium Drive, Baton Rouge, LA 70803, (2) Department of Chemical and Biomolecular Engineering, Clemson University, 127 Earle Hall, Clemson, SC 29634-0909, (3) Center for Advanced Microstructures and Devices, Louisiana State University, 6980 Jefferson Highway, Louisiana State University, Baton Rouge, LA 70806
Mn-promoted Fe-based Fischer-Tropsch catalysts with a formulation of (100-x)Fe/xMn/5Cu/17Si, where x is 20 or smaller, were prepared using co-precipitation were and characterized using Fe and Mn K-edge XANES in transmission. In order to perform a Fe “fingerprint analysis”, θ-Fe3C was synthesized as a standard using CO temperature programmed reduction of Fe2O3, which are shown to be successful from the oxidation state and slope of the edge jump. The Fe XANES data shows Fe in 80Fe/20Mn sample being less reduced than the 95Fe/5Mn sample, meaning that the increase in Mn loading decreases the reduction of Fe. An interesting dampening of the K-edge manganese peak of the 80Fe/20Mn sample demonstrates a phase unique from the standards, which corresponds to either a mixed metal oxide or carbide. The increased interaction between iron and manganese in the 80Fe/20Mn catalyst is believed to cause the increases in catalytic activity found in a related study.
 

Clean Energy, Fuels and Chemicals from Biomass
1:30 PM-3:25 PM, Wednesday, April 9, 2008 Morial Convention Center -- Rm. 242, Oral

Division of Fuel Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008