Diaphragm Electrolysis Cell For Electrolysis Of Carbon Dioxide To Carbon Monoxide By-product Chlorine And Sodium Bicarbonate

Electrochemical conversion of carbon dioxide to carbon monoxide,and use it as the feedstock to produce clean fuels and value-added chemicals,has atracted great interest in the field of chemical industry.However,owing to the lack of industrially applicable electrochemical reaction devices,However,owing to the lack of efficient electrode electrolyzer,no breakthrough has been achieved untill today.Consequently,we cannot open up new industry based on novel technology.In this thesis,we attempt to develop a new technology for the electro-reduction of carbon dioxide with industrial application prospects,which can electrically reduce carbon dioxide to carbon monoxide in an organic electrolyte,while by-product chlorine and sodium bicarbonate.The obtained carbon monoxide and chlorine are used to synthesize phosgene.Phosgene is an important fine chemical raw material that can be used to produce high value-added chemical products such as medicines,pesticides,dyes,etc.Sodium bicarbonate is widely used in food,glass,medicine,and other fields.application.Through the above approach,the problem of excessive carbon dioxide emissions can be solved,and economic benefits can be created,so it has important theoretical research value and engineering application prospects.The main research contents are as follows:(1)Using perfluorosulfonic acid membrane to separate the electrolytic cell into a cathode compartment and an anode compartment,with tetrabutylammonium perchlorate/propylene carbonate as the catholyte,gold flakes as the cathode,and sodium chloride as the anolyte,Ir O₂/Ti coated electrode is used as anode to form diaphragm electrolytic cell.During the electrolysis reaction,carbon dioxide undergoes an electroreduction reaction on the cathode to produce carbon monoxide,and chlorine ions undergo electrooxidation on the anode to produce chlorine gas.Sodium ions in the anode compartment pass through the perfluorosulfonic acid membrane and enter the catholyte,and the bicarbonate ions generated by the cathode reaction combine to obtain sodium bicarbonate.(2)The kinetics of the electro-reduction reaction of carbon dioxide is studied.The gas chromatography test results show that carbon dioxide can undergo an electro-reduction reaction on the cathode to generate carbon monoxide.When the electrode potential reaches-2.4V,the current density of the generated carbon monoxide reaches16m A/cm²,and the current efficiency reaches 91%.During the long-period electrolysis test,the electrolyte does not deteriorate and the electrode is not poisoned.(3)The kinetic process of the oxidation reaction of chloride ions on the anode was studied.The qualitative and quantitative analysis of the anode gas phase reaction products was carried out using starch potassium iodide test paper and iodometric titration.The results showed that when the anode potential was higher than 1.27V(vs SHE),chlorine ions can be oxidized on the anode to generate chlorine gas.Constant potential electrolysis is carried out in saturated sodium chloride aqueous solution.When the potential is 1.4V,the current density can reach 1.6m A/cm²,and the current efficiency can reach 94%.(4)During the constant potential electrolysis process,it was found that a large amount of white flocculent product was produced in the catholyte.XRD test results showed that the flocculent product was sodium bicarbonate.Calcining this flocculent product can obtain soda ash.Compared with the traditional method,this method has the advantages of simple equipment,low cost,and no solid waste generation.The diaphragm electrolytic cell studied in this paper can simultaneously generate three products of carbon monoxide,chlorine,and sodium bicarbonate.It has the advantages of simple operation method,high product added value,and strong industrial applicability.It has a broad field of Industrial application prospects in carbon dioxide emission reduction and electric energy storage.