Copper-Containing Catalysts

5 Copper-Containing Catalysts. - 2.5.1 Copper Chromite Catalysts. Hydrogenation of Dodecanoic Acid. 2.5.1.1 Literature Background. Copper chro- 

Conventional technology of the hydrogenolysis of fatty acid methyl esters to the corresponding fatty alcohols uses copper chromite or zinc chromite based catalysts and the manufacturing process requires high pressures (200-300 bar) and temperatures (250-300 °C). The activity of copper chromite catalysts was significantly increased by the addition of zinc.  

Hubaut et has studied the liquid phase hydrogenation of polyunsaturated hydrocarbons and carbonyl compounds over mixed copper-chromium oxides. The selectivity of monohydrogenation was almost 100 % for conjugated dienes but much lower for a,p-unsaturated carbonyls. This was due to the adsorption competition between the unsaturated carbonyls and alcohols as primary products. It was suggested that the hydrogenation site was an octahed-rally coordinated Cu ion with two anionic vacancies, and an attached hydride ion. The Cr ion in the same environment was probably the active site for side reactions (hydrodehydroxylation, nucleophilic substitution, bimolecular elimination). 

All these results suggest that in copper chromite type catalysts ionic copper species can be the active site for the hydrogenation of carbonyl compounds. 

With respect to the activity of these catalysts in the hydrogenation of dodecanoic acid, it is interesting to note that the higher the amount of Cu surf. of the CZA catalysts the higher the activity, i.e. the conversion of dodecanoic acid, of these types of catalysts (see Table 28).  

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Synthetic phenol capacity in the United States was reported to be ca 1.6 x 10 t/yr in 1989 (206), almost completely based on the cumene process (see Cumene Phenol). Some synthetic phenol [108-95-2] is made from toluene by a process developed by The Dow Chemical Company (2,299—301). Toluene [108-88-3] is oxidized to benzoic acid in a conventional LPO process. Liquid-phase oxidative decarboxylation with a copper-containing catalyst gives phenol in high yield (2,299—304). The phenoHc hydroxyl group is located ortho to the position previously occupied by the carboxyl group of benzoic acid (2,299,301,305). This provides a means to produce meta-substituted phenols otherwise difficult to make (2,306). VPOs for the oxidative decarboxylation of benzoic acid have also been reported (2,307—309). Although the mechanism appears to be similar to the LPO scheme (309), the VPO reaction is reported not to work for toluic acids (310). 

Acetophenone is separated for hydrogenation to 1-phenylethanol, which is sent to the dehydrator to produce styrene. Hydrogenation is done over a fixed-bed copper-containing catalyst at 115—120°C and pressure of 8100 kPa (80 atm), a 3 1 hydrogen-to-acetophenone ratio, and using a solvent such as ethylbenzene, to give 95% conversion of the acetophenone and 95% selectivity to 1-phenylethanol (186,187). 

Formaldehyde also reacts with butadiene via the Prins reaction to produce pentenediols or their derivatives. This reaction is cataly2ed by a copper-containing catalyst in a carboxyUc acid solution (57) or RuCl (58). The addition of hydrogen also proceeds via 1,2- and 1,4-addition. 

Several other important commercial processes need to be mentioned. They are (not necessarily in the order of importance) the low pressure methanol process, using a copper-containing catalyst which was introduced in 1972 the production of acetic add from methanol over RhI catalysts, which has cornered the market the methanol-to-gasoline processes (MTG) over ZSM-5 zeolite, which opened a new route to gasoline from syngas and ammoxidation of propene over mixed-oxide catalysts. In 1962, catalytic steam reforming for the production of synthesis gas and/or hydrogen over nickel potassium alumina catalysts was commercialized. 

The first reaction produces methanol with a low hydrogen consumption, but evolves significantly greater amounts of heat. The second reaction evolves less heat, but consumes more hydrogen and produces the byproduct steam. Thermodynamically, low temperatures and high pressures favor methanol formation. The reactions are carried out with copper-containing catalysts with typical reactor conditions of 260°C and 5 MPa (Probstein and Hicks, 1982). 

All the copper containing catalysts reported in Table 2 are associated with ZnO or Cr203. However, within the literature supports such as Si02 [e.g., ref. 38], those... 

The reactions of ethanol, ethyl acetate, and acetic acid in the presence of hydrogen on silica-supported copper were chosen to illustrate kinetic analyses of reaction schemes leading to multiple reaction products. Copper-containing catalysts are extremely important for the reduction of oxygenated compounds, such as alcohols, esters, and carboxylic acids. Such materials... 

Frank B, et al. Steam reforming of methanol over copper-containing catalysts influence of support material on microkinetics. J Catal. 2007 246(l) 177-92. 

Tessag Edeleanu GmbH Acetone Isopropanol Dehydrogenation reaction with copper-containing catalyst 3 1983... 

Metal-bis(oxazoline) complexes were widely used as effective catalysts for enantioselective Diels-Alder reactions. Two research groups could achieve excellent diastereo- and enantio-selectivity for the reaction of cyclopentadiene (54) and the acrylamide 55 (Fig. 9) [27]. Yet the decisive feature is only recognizable when both studies are analyzed together. In both cases the endo products are obtained in high selectiv-ities using either the magnesium- or the copper-containing catalyst. However, despite the same... 

Dehydrogenation of methanol over copper containing catalysts at the temperature range 200—400° C is achieved by two Hnearly indepen dent stepwise channels... 

The H-ZSM-5 (Si/Al=25, PQ Corp.) and Silicalite (S-1) zeolites were used to prepare the microporous copper-containing catalysts, Cu-ZSM-5 and Cu-S-1. ( We recall that S-1 has the same framework topology of ZSM-5, but without AP+ ions in the framework, and therefore S-1 is an all silica materials as MCM-41.) S-1 was prepared using TEOS and a 20% aqueous solution of tetrapropylammonium hydroxide (TPA-OH) (Fluka-purum). TEOS was poured in the TPA-OH solution. The resulting mixture was kept at 333 K for 3 h and then heated under autogenous pressure in a 350 mL stainless autoclave in an oven at 448 K for 24 h, without stirring. The solid was washed with water, dried 2 h at 383 K and finally treated in air at 823 K for 5 h. Further details were reported in Ref 4. 

Frank, B., Jentoft, F.C., Soerijanto, H., Krohnert, J., Schlogl, R., and Schomacker, R. Steam reforming of methanol over copper-containing catalysts Influence of support material on microkinetics. Journal of Catalysis, 2007, 246 (1), 177. 

Shown in Figures 3 and 4 are the results of temperature programmed surface reaction on an iron, 1% Cu/Fe, and 2.5% Cu/Fe catalysts following 24 h of reaction in synthesis gas (H2/CO=0.7). The TSPR behavior of the two copper-containing catalysts was quite similar. The major difference was between the copper-containing and the iron-only catalyst. Less CH carbon is formed on the iron-only eatalyst, and the substantial amount of graphitic carbon formed on the iron-only catalyst is considerably less reactive. Also, the more copper in the catalyst, the more... 

Ostromyslenskii (Ostromisslenskii) reaction. Dehydrogenation of ethanol over copper-containing catalysts and conversion of the acetaldehyde ethanol mixture to butadiene by passage at high temperature over silica gel containing a small amount of tantalum oxide. 

The synthesis of arsonium ylides 384 from diazocyclopentadienes 383 and tri-phenylarsine has been reexamined with respect to the efficiency of various copper-containing catalysts Whereas copper bronze gave only ca. 55 % of ylide, yields over 80% were provided by the use of Ou(II) complexes of p-diketonates derived from acetylacetone, 3-methylacetylacetone, benzoylacetone or dibenzoylmethane, as well as by bis[4-(phenylimino)-2-pentanonato-N,0-]copper(II) and Cu(II) acetate, all used in boiling benzene. The sterically more demanding complex bis(dipivaloyl-methanato)copper(II) as well as dichlorodipyridinecopper(II) proved less efficient. CopperfTI) tartrate, the dibenzo-14-crown 6/copper complex and furthermore the acetylacetonate complexes of Co, Ni, Pt and Zn were totally ineffective. When 383a was decomposed by Cu(acac)2 in the presence of pyridine or thioanisole. 

About 50% NO c conversion is obtained both with a platinum-based catalyst at temperatures below about 570 K, and with a copper-based catalyst at temperatures above about 570 K. These temperatures coincide with the temperature range in which these two catalysts convert hydrocarbons. However, whereas the platinum-containing catalyst is able to convert carbon monoxide efficiently, the copper-containing catalyst generates carbon monoxide, probably by the incomplete oxidation of the added hydrocarbons [71]. 

The situation changes dramatically with raising the temperature. Figure 1 demonstrates the effect of the temperature on the oxidative chlorination of ethane over the well-known conventional salt CuCb—KCl/silica gel copper-containing catalyst. 

Di-n-propylamine can be produced in industrial scale by the alkylation of ammonia with n-propanol on Ba(OH)2 modified Ni/Al203 catalyst [2], by the reductive amination of propionaldehyde over a cobalt-containing catalyst [3] or by the hydrogenation acrylonitrile in n-exane on Ni/Al203 catalyst [4,5]. However, only scare data is available about the alkylation of ammonia or i-butylamine with i-butanol [6-10]. Di-i-butylamine was prepared from i-butanol over alumina at 370-380 C with 28 % yield [7]. 20 wt% Co - 5 wt% Ni catalyst supported on alumina was used to prepare di-i-butylamine fi"om i-butanol and i-butylamine at 200 °C with a yield of 60. 6 [10]. Aliphatic mixed secondary amines prepared from a pimary amine and an alcohol were usually obtained on copper-containing catalysts at 190-200 C with 30-50 % yields [11-13]. 

In the preparation of EtNHn-Bu from ethylamine and n-butanol over a commercial CuO-ZnO-AI2O3 catalyts the highest yield, about 76 % was obtained at 190 C and EtNH2/n-BuOH molar ratio 5 or above. Here we report the first time such a high yield in the preparation of a mixed aliphatic secondary amine over a copper-containing catalyst. 

STEREOSELECTIVE HYDROGENATION OF D-FRUCTOSE TO D-MANNITOL ON SKELETAL AND SUPPORTED COPPER-CONTAINING CATALYSTS... 

Table 25 Composition of different copper-containing catalysts (Reproduced from ref. 257 with permission)...

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