Support and cluster effects on synthesis gas conversion with supported ruthenium clusters

Surface-Mediated Organometallic Synthesis: High-Yield and Selective Syntheses of Neutral and Anionic Ruthenium Carbonyl Clusters by Controlled Reduction of Silica-Supported RuCl3in the Presence of Na2CO3or K2CO3

“…20 However it is known that, on the surface of Al 2 O 3 and MgO, [H 3 Ru 4 (CO) 12 ] -is converted to [Ru 6 C(CO) 16 ] 2by treatment under CO + H 2 (molar ratio 1:1) at 200 °C. 19 Therefore, [H 3 Ru 4 (CO) 12 ] -could be an intermediate species in the silica-mediated synthesis of [Ru 6 C(CO) 16 ] 2described above. Treatment of [Ru(CO) 3 Cl 2 (HOSit)] (5 wt % of Ru with respect to SiO 2 ) with a slurry of K 2 CO 3 (molar ratio K 2 CO 3 :Ru ) 10:1) in CH 2 Cl 2 , followed by evaporation of the solvent, drying under vacuum (10 -2 Torr) for 3 h at 100 °C, and reduction for 24 h under 1 atm of CO + H 2 (molar ratio 1:3) at lower temperatures such as 100 °C, affords a mixture of [H 4 Ru 4 (CO) 12 ] (10% yield) and K[H 3 Ru 4 (CO) 12 ] (60% yield, Table 2) which can be separated by selective extraction under N 2 from the silica surface with CH 2 Cl 2 and acetone, respectively.…”

“…By working with a low surface basicity (molar ratio Na 2 CO 3 :Ru ) 3:1), we found that silica-supported [Ru 3 (CO) 12 ] can be easily converted to [H 4 Ru 4 (CO) 12 ] in the presence of H 2 (Scheme 2). In the absence of H 2 and on a more basic silica surface, [Ru 3 (CO) 12 ] behaves as on the surface of MgO 19 or in basic solution. 28 Treatment of silica-supported [Ru 3 (CO) 12 ] (2 wt % of Ru with respect to SiO 2 ) with a slurry of K 2 CO 3 in CH 2 Cl 2 (molar ratio K 2 CO 3 :Ru ) 10:1), followed by evaporation of the solvent and treatment under 1 atm of CO at 80 °C for 24 h, affords pure K[HRu 3 (CO) On the other hand, when silica-supported [Ru 3 (CO) 12 ] (2 wt % of Ru with respect to SiO 2 ) is treated for 24 h with CO + H 2 (molar ratio 1:3, 1 atm) at 80 °C on a basic silica surface (molar ratio K 2 CO 3 :Ru ) 10:1), K[H 3 Ru 4 (CO) 12 ] is obtained quantitatively.…”

Slurry-phase Fischer-Tropsch synthesis and kinetic studies over supported cobalt carbonyl derived catalysts

“…Recently we have been interested in slurry reactor processing and the development of novel catalysts for the slurry-phase FT synthesis (Bauer et al, 1984). One approach toward catalyst development that has given promising results in our laboratory has been the use of metal carbonyl clusters as precursors to metal catalysts (Pierantozzi et al, 1983). Catalysts prepared from metal carbonyls generally show different catalytic behavior compared to "conventionally" prepared catalysts, which are made by using cobalt salts.…”

“…Catalysts prepared from metal carbonyls generally show different catalytic behavior compared to "conventionally" prepared catalysts, which are made by using cobalt salts. A significant amount of literature now exists on the study of metal carbonyl dervied catalysts (Bailey and Langer, 1981;Brown, 1981; Burwell, 1984;Phillips and Dumesic, 1984;Pierantozzi et al, 1983;Yermakov, 1983; Zwart and Snel, 1985).…”

CO hydrogenation over alumina‐supported sulfide cluster catalysts

“…Pierantozzi et al (1983) isolated the carbido complex [RU,C(CO),~]~-as a decomposition product of the reaction between Ru,(CO),, and MgO during CO hydrogenation. Carbides have also been reported to stabilize the dispersion of catalysts produced from Fe3(C0)12 (Lazar et al, 1984).…”