Structure and reactivity of bimetallic Ni-Au catalysts for syngas production and utilization

FUEL 70

Ya-Huei Chin, chin@berkeley.edu1, David L King, david.king@pnl.gov2, Yong Wang, yongwang@pnl.gov2, and Hyun-Seog Roh, hsroh@kier.re.kr3. (1) Department of Chemical Engineering, University of California, Berkeley, 201 Gilman Hall, Berkeley, CA 94720-1462, (2) Institute for Interfacial Catalysis, Pacific Northwest National Laboratory, P.O. Box 999, Richland, WA 99352, (3) Korea Institute of Energy Research, 71-2, Jang-dong, Yuseong-gu, Daejeon 305-343, South Korea
A key issue regarding the use of Ni catalysts for hydrocarbon steam reforming is their stability against carbon deposition. This deposition can be retarded by addition of promoter atoms such as Au that are thought to reside at the coordinatively unsaturated step and kinks sites. We have characterized the structure of Au-promoted Ni catalysts and investigated their reactivity toward syngas production and consumption. XPS and chemisorption results suggest the formation of a surface Au-Ni alloy. Methane steam reforming shows an effect of Au surface alloying through a modest reduction in initial activity and deactivation rate. However, CO DRIFT and methanation studies show little effect of Au addition. These latter results are consistent with surface reconstruction in the presence of CO, which minimizes the impact of Au. This study points out the contrast in findings from different characterization methods, and emphasizes the importance of characterizing bimetallic catalysts under actual working conditions.
 

Advances in Hydrogen Production
8:30 AM-11:50 AM, Monday, 11 September 2006 Palace -- Marina Room, Oral

Division of Fuel Chemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006