Heterogeneous Catalysts Using On The Electrosynthesis Of Dimethyl Carbonate

Dimethyl carbonate (DMC) is viewed as an environmentally benign intermediatebecause of its negligible eco-toxicity and its versatile chemical applications. DMC hasbeen proposed as a replacement for phosgene, dimethyl sulfate, chloromethane and othertoxic/carcinogenic substances as methylating reagents, carbonylating reagents and esterinterchange reagents. In addition, DMC are employed as electrolytes in energy materialsand are widely used as fuel additives and polar solvents. Furthermore, DMC is also avery important synthetic intermediate and building block in the current chemical industry.Thus, from the above point of view, DMC have received increasing attentions in eacharea.Several catalytic processes have been developed for the synthesis of DMC,including phosgenation, oxidative carbonylation of methanol, direct synthesis from CO2and methanol, urea methanolysis, and transesterification. As green chemistry is currentlya major global theme, green catalytic processes, such as the electrochemical synthesis ofDMC, have captured the interest of many researchers. Our group developed a uniqueelectrochemical system to overcome the problems existed in above well-establishedmethods. To date, the majority of the known homogeneous catalysts for theelectro-synthesis of DMC are based on noble metal salts and transition metal N-donorcomplexes. However, exorbitant cost and poor recycling of the catalysts limited itsapplications.Metal-organic frameworks (MOFs) are a specific class of coordination polymerswith high crystallinity, high porosity, and a large number of metal sites. MOFs areattractive materials because of their unique properties, which include large surface areas,tunable pore sizes, and open metal sites. The applications of a Cu(II)-based MOF as aheterogeneous electrocatalyst for the electrocatalytic oxidative carbonylation of methanolto DMC are first described in this work. At the first stage, this paper synthesized threeMOFs: Cu-BTC, Cu-bipy-BTC, Cu-bipy-btec. And then we investigated itselectrocatalytic properties. In summary, we demonstrated the heterogenization of anon-noble metal complex for the electrosynthesis of DMC using a MOF as the electrocatalyst. This heterogeneous catalytic system exhibited a favorable electrocatalyticperformance. The Cu-based MOF was stable during the electrolytic reaction and could bereused at least four times. The results of this investigation are of great signi ficance forthe further development of MOFs in the electrocatalytic field. The XRD result suggeststhat the presence of GO did not have any noticeable impact on the formation of thecrystalline frameworks. A smaller size of the block structure and more dispersed blocksthan MOF alone were observed after the introduction of graphene oxide. Theelectrocatalytic performance of the hybrid material also has been improved.When the MOF was used as electrocatalyst, the DMC yield could reach a maximumof73.11μmol per10mL methanol. And the MOF/GO hybrid material was used aselectrocatalyst, the DMC yield could reach a maximum of110.33μmol per10mLmethanol.Based on the conclusion of above investigations, in this paper, the homogeneouscatalyst and heterogeneous catalyst for mechanism of this electrosynthetic reaction havebeen discussed, and further illustrated the nature of the electrocatalytic reaction.