Oxidative Carbonylation Of Methanol Research Articles

Synthesis of Dimethyl Carbonate(DMC) by Oxidative Carbonylation of Methanol Using Polymer-supported CuCl2 Catalyst.

Polymer, including 2, 2'-bipyridine, poly(4-methyl-4'-vinyl-2, 2'-bipyridine)(Pvbpy), was investigated for the synthesis of dimethyl carbonate (DMC) as a support for CuCl2, by oxidative carbonylation of methanol in the liquid-phase. The CuCl2 complex (Pvbpy-CuCl2) was insoluble in methanol, and the reaction system was heterogeneous. The Pvbpy-CuCl2 catalyst showed considerable catalytic activity (DMC yield: 44.4% and DMC selectivity: 92.6%, at methanol conversion: 1.79%), which is comparable to the previously reported data of poly (vinylpyridine)(PVP)-CuCl2 catalyst; the Pvbpy-CuCl2 catalyst could be recycled after filtration and washing thrice, provided, not having lost activity. The corrosion originating from Cl- was greatly improved by immobilizing the CuCl2 by Pvbpy. Elimination of CuCl2 from the Pvbpy support was observed during the reaction. In the first reaction, about 38% of the initially supported Cl was released, and in the second and the third reactions, most of the Cl was retained. The rate of corrosion of stainless steels in the first use of the catalyst (0.6m gh-1 for HC276) was greater than that in the rate of the second and the third uses (<0.1mg h-1). These results are closely related to the amount of Cl- released from the Pvbpy support, which demonstrates that the main cause of corrosion in the catalytic system is Cl- released from the Pvbpy-CuCl2 catalyst. From XPS study of the catalyst, it became obvious that Cu(II) was gradually reduced to Cu(I) during the reaction.

Novel type of heterogenized CuCl2 catalytic systems for oxidative carbonylation of methanol

A novel type of heterogenized CuCl2 catalysts was designed for the oxidative carbonylation of methanol to dimethyl carbonate (DMC) taking account of the plausible reaction mechanism and intermediates. To prevent severe corrosion of the reaction equipment materials due to Cl− while keeping the catalytic activity of the homogeneous CuCl2 catalyst, we adopted, as supports (or ligands) of CuCl2, four polymers, bearing a 2,2′-bipyridine (bpy) or pyridine (py) unit, namely, poly(2,2′-bipyridine-5,5′-diyl) (Pbpy), poly(pyridine-2,5-diyl) (Ppy), poly(N,N′-bisphenylene-2,2′-bipyridine-4,4′-dicarboxylic amide) (Bpya), and poly(4-methyl-4′-vinyl-2,2′-bipyridine) (Pvbpy), together with one chelate compound, 8-quinolinol. The catalytic activity, stability of heterogenized CuCl2 and their corrosivities to stainless steels were examined in the liquid-phase reaction of the oxidative carbonylation of methanol. These polymer-supported catalysts showed considerable catalytic activity and stability for the DMC synthesis. In particular, the Pbpy-CuCl2 and Ppy-CuCl2 catalysts exhibited high DMC yields and selectivity comparable to those of the homogeneous CuCl2 catalyst. This high activity appears to be associated with the presence of the π-conjugated system in the polymers, which affect the redox reactions of Cu involved in the catalytic reaction. All of the polymer-supported CuCl2 catalysts could be easily recycled after filtration, and the initial catalytic activity was maintained after three times of use. The corrosive characters of the catalysts were closely related to CuCl2 leaching from the supports, which reflects the ability of supports to coordinate Cu. These experimental results suggest that both the electronic structure and the coordination ability of the polymer supports are key factors for the development of an effective catalytic system.

Dimethyl carbonate synthesis by oxidative carbonylation on activated carbon supported CuCl 2 catalysts: catalytic properties and structural change

Catalytic properties of CuCl 2 catalysts supported on activated carbon in the synthesis of dimethyl carbonate by oxidative carbonylation of methanol were investigated. Structural changes during the reaction were studied. It was suggested that dimethyl carbonate formation rate is strongly related to Cl/Cu ratio and CO formation rate is higher on the catalyst with Cu oxychloride than on that with Cu–Cl–OH.

Oxidative carbonylation of methanol as a synthesis route to oxamide: statistically designed experiments

Oxidative carbonylation of methanol as a synthesis route to oxamide: statistically designed experiments

Oxidative carbonylation of organic compounds by carbon monoxide and transition-metal salt catalysts

1. The yield of methyl acrylate during oxidative carbonylation of ethylene in the presence of chlorides of palladium and copper sharply increased with the addition of LiCl and during the increase of the partial pressure of carbon monoxide in the gaseous mixture. 2. Highly effective as a catalyst, methanol served simultaneously as the reagent and formed methyl acrylate in yields approaching 73%. 3. In oxidative carbonylation of methanol, the system MnCl2-CuCl2-LiCl was highly active. At 180°, 40 atm carbon monoxide pressure, and 22.5 atm oxygen the yield of dimethyl carbonate approached 89%.