| AVS 54th International Symposium | |
| Surface Science | Tuesday Sessions |
| Session SS1-TuM |
| Session: | Catalytic Chemistry of Hydrocarbons |
| Presenter: | A.S.Y. Chan, UOP - Honeywell |
| Authors: | A.S.Y. Chan, UOP - Honeywell S.R. Bare, UOP - Honeywell |
| Correspondent: | Click to Email |
Isomerization of straight chain alkanes to their branched isomers is an important industrial process to upgrade the octane value of gasoline. A solid acid catalyst that is effective for the isomerization of light alkanes is sulfated zirconia. In 1990, Sun Refining and Marketing Co. patented a modified sulfated zirconia catalyst containing transition metals (e.g. Mn, Fe) as promoters. More recently, in 2003, UOP patented an improved catalyst that was promoted by at least one lanthanide. In this talk, we will focus on the surface characterization of model sulfated zirconia catalysts that are Mn-promoted and lanthanide-promoted. By using a combination of X-ray Photoelectron Spectroscopy (XPS) and Low Energy Ion Scattering (LEIS), the location of promoters and their subsequent effect on the structure of the zirconia support will be elucidated. In addition, the accessibility of active metal and acid sites on these two promoted catalysts will be discussed. Finally, we will generalize the combined XPS and LEIS studies to provide a more complete picture of other catalytic systems: examples will be drawn from novel zeolites used in alkylation reactions, and Pd-based selective hydrogenation catalysts.