skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Cation promotion effect in zeolite-supported F-T catalysts: Final report

Technical Report ·
OSTI ID:7055533

The present work was undertaken to investigate systematically the influence of Group IA neutralizing cations on CO hydrogenation over zeolite-supported ruthenium catalysts. These catalysts were prepared from NH/sub 4/Y, LiY, NaY, KY, RbY, CsY, NaX, KL, and Na-mordenite zeolites by ion exchange with ruthenium hexammine chloride. The nature of the group IA cations was found to have little effect on chemisorptive properties and on the activity and chain growth probability in CO hydrogenation on Ru. However, it was established that secondary acid-catalyzed reactions of the primary olefinic products from CO hydrogenation can play a major role in shaping product selectivity. Using model reactions such as olefin transformations on the zeolites without the metal, it was established that the strength of the acid sites is a strong function of the nature of the neutralizing alkali cations remaining in the zeolite. Acid site strength was found to decrease with molecular weight of the alkali cation used. This study established the bifunctional nature of the zeolite-supported F-T catalysts and its importance in CO hydrogenation. The results suggest that the catalyst selectivity can be controlled by varying the strength of the zeolite acid sites, the most important active centers for secondary reactions of the primary olefinic F-T products. Depending on the concentration and the strength of the acid sites, a function of the Si/Al ratio and the nature of the residual neutralizing cations, various competitive reaction paths can be observed for the transformation of olefinic compounds. These include isomerization, oligomerization, cracking, hydrogen transfer, etc. 67 figs., 32 tabs.

Research Organization:
Pittsburgh Univ., PA (USA). Dept. of Chemical and Petroleum Engineering
DOE Contract Number:
FG22-83PC60805
OSTI ID:
7055533
Report Number(s):
DOE/PC/60805-T12; ON: DE87002505
Resource Relation:
Other Information: Portions of this document are illegible in microfiche products. Original copy available until stock is exhausted
Country of Publication:
United States
Language:
English

Similar Records

Effect of group IA cations on CO hydrogenation over Ru/zeolites
Thesis/Dissertation · Wed Jan 01 00:00:00 EST 1986 · OSTI ID:7055533

Effect of group IA cations on CO hydrogenation over Ru/Y-zeolites
Journal Article · Sat Nov 01 00:00:00 EST 1986 · J. Catal.; (United States) · OSTI ID:7055533

Cation promotion effects in zeolite-supported F-T catalysts. Fourth quarterly report, June 1984-August 1984. [Cyclopropane]
Technical Report · Sat Sep 01 00:00:00 EDT 1984 · OSTI ID:7055533