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Effects of Dispersion in Carbon Monoxide Adsorption and Carbon Monoxide Hydrogenation over Alumina-supported Ruthenium Catalysts

1984; Oxford University Press; Volume: 57; Issue: 4 Linguagem: Inglês

10.1246/bcsj.57.938

1348-0634

Toshio Okuhara, Tomoo Kimura, Kenji Kobayashi, Makoto Misono, Yukio Yoneda,

Catalysis and Hydrodesulfurization Studies

Abstract Ru/Al2O3 catalysts prepared from [Ru3(CO)12] and from RuCl3 were characterized by chemisorption of H2 and CO, and by infrared measurement of adsorbed CO. By using these catalysts, the effect of the dispersion on the activity and selectivity in CO hydrogenation was studied. Ru/Al2O3 catalysts prepared from [Ru3(CO)12] showed high dispersions (>80%), and were more active and selective for the production of olefins in the CO hydrogenation than Ru/Al2O3 catalysts prepared from RuCl3. However, the distribution of product hydrocarbons was not sensitive to the Ru dispersion. Infrared study of adsorbed CO revealed that twin-type CO (Ru(CO)2) as well as linear-type CO (Ru–CO) was present on each Ru/Al2O3. The twin-type CO was more strongly held and was less reactive to hydrogenation. For each series of Ru/Al2O3, the turnover frequency increased as the dispersion decreased. This change has been explained by the poisoning effect of the twin-type CO. The higher activity of Ru/Al2O3(A) was ascribed to the lower concentration of the twin-type CO on the surface.