Raney copper-based catalysts

Development of high performance Raney copper-based catalysts for methanol synthesis from CO2 and H2... 

The use of copper-based catalysts for the reactions of ester hydrogenolysis and alcohol dehydrogenation is well established [2-26, 30,31]. Raney -type skeletal copper catalysts are widely used in these reactions [5-11,17-26,30,31]. However, significant catalyst deactivation is experienced [5-6,25-29]. Evans et al studied the hydrogenolysis of formates in the gas phase over a variety of copper-based catalysts, including skeletal copper and copper chromite... 

Mitsui Toatsu Chemical, Inc. disclosed a similar process usiag Raney copper (74) shortiy after the discovery at Dow, and BASF came out with a variation of the copper catalyst ia 1974 (75). Siace 1971 several hundred patents have shown modifications and improvements to this technology, both homogeneous and heterogeneous, and reviews of these processes have been pubHshed (76). Nalco Chemical Company has patented a process based essentially on Raney copper catalyst (77) ia both slurry and fixed-bed reactors and produces acrylamide monomer mainly for internal uses. Other producers ia Europe, besides Dow and American Cyanamid, iaclude AUied CoUoids and Stockhausen, who are beheved to use processes similar to the Raney copper technology of Mitsui Toatsu, and all have captive uses. Acrylamide is also produced ia large quantities ia Japan. Mitsui Toatsu and Mitsubishi are the largest producers, and both are beheved to use Raney copper catalysts ia a fixed bed reactor and to sell iato the merchant market. 

The hydrogenation of nitrobenzenes to anilines is carried out in a liquid phase or in a vapor phase, in either a fixed-bed or a fluidized-bed reactor. For vapor-phase processes, copper-based catalysts97 and sulfided nickel98 are among those most frequently used. For liquid-phase processes, supported nickel99 and Raney Ni100 as well as supported palladium101 are the catalysts most commonly employed. 

In previous studies the authors have reported that metals oxides such as GaaOa, AI2O3, Zr02 and Cr203 contained in Cu/ZnO-based catalysts have an important role to improve simultaneously the activity and the selectivity[1, 2]. Unlike Cu/ZnO-based catalysts, Raney copper catalysts have not been widely reported in the literature as practical catalysts for methanol synthesis. However, 20 years ago Wainwright and co-workers have been the first to report the potentiel use of Raney Cu and Raney Cu-Zn as catalysts to produce methanol from syngas to use as synthetic liquid fuel [3]. Recent works of Wainwright et al. on methanol synthesis... 

Alcan 756 C.l. 77775 Carbonyl nickel powder CCRIS 427 EINECS 231-111-4 EL12 Fibrex Fibrex P HSDB 1096 Ni 0901-S Ni 270 Ni 4303T Nichel Nickel 200 Nickel 201 Nickel 205 Nickel 207 Nickel 270 Nickel catalyst Nickel compounds Nickel, elemental Nickel, elemental/metal Nickel particles Nickel sponge NP 2 Raney alloy Raney nickel RCH 55/5. Metallic element, used in electroplating, as a hydrogenation catalyst and in iron- and copper-based alloys. Metal mp = 1453° bp (calc) = 2732° d= 8.908. Atomergic Chemetals Inco, Europe Lancaster Synthesis Co. Sigma-Aldrich Fine Chem. 

This makes the use of catalysts indispensable. Copper, nickel, zinc based systems are used in the vapor phase, promoted or not in metallic or oxide form, and possibly deposited on a support Tire lower temperature (S 150 Q reaction can be carried out in the liquid phase, in the presence of Raney nickel. Hie thermodynamic equilibrium in this case is shifted in the desired direction by the continuous removal of the hydrogen produced. It is also necessary to extract the acetone from the reaction medium upon its formation, by vaporization for example, owing to the inhibitory action it exerts on the activity of the catalyst... 

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