Anion exchanger fillings through which flow can occur for electrolyte splitting in co2 electrolysis for better spatial distribution of gassing

Abstract

An electrolysis cell having a multi-chamber structure, wherein an anion exchanger with a first ion exchanger membrane connects to a cathode chamber, wherein a salt bridge chamber connects to the first ion exchanger membrane, the salt bridge chamber with a fixed anion exchanger. An electrolysis system has such an electrolysis cell and a method for electrolysis of CO2 uses such an electrolysis cell or electrolysis system.

1 . An electrolysis cell, comprising:
 a cathode compartment comprising a cathode;   a first ion exchange membrane, which contains an anion exchanger and which is adjacent to the cathode compartment, wherein the cathode comes into contact with the first ion exchange membrane;   an anode compartment comprising an anode; and   a first separator, which is adjacent to the anode compartment;   a salt bridge compartment, wherein the salt bridge compartment is arranged between the first ion exchange membrane and the first separator, wherein the salt bridge compartment comprises a solid anion exchanger, which is at least partially in contact with the first ion exchange membrane.   
     
     
         2 . The electrolysis cell as claimed in  claim 1 ,
 wherein the solid anion exchanger comprises in the salt bridge compartment cations, which are immobilized in a polymeric backbone.   
     
     
         3 . The electrolysis cell as claimed in  claim 1 ,
 wherein the solid anion exchanger is present as a bed and/or a porous structure.   
     
     
         4 . The electrolysis cell as claimed in  claim 1 ,
 wherein the solid salt bridge compartment further comprises uncharged particles, nonionic ion exchangers and/or cation exchangers.   
     
     
         5 . The electrolysis cell as claimed in  claim 1 ,
 wherein the first separator is a cation exchange membrane, a bipolar membrane or a diaphragm.   
     
     
         6 . The electrolysis cell as claimed in  claim 1 ,
 wherein the solid anion exchanger is basic, or strongly basic.   
     
     
         7 . The electrolysis cell as claimed in  claim 1 ,
 wherein the solid anion exchanger is hydrophilic.   
     
     
         8 . The electrolysis cell as claimed in  claim 1 ,
 wherein the salt bridge compartment further comprises a solid cation exchanger, which is at least partially in contact with the first separator.   
     
     
         9 . An electrolysis system, comprising:
 an electrolysis cell as claimed in  claim 1 .   
     
     
         10 . The electrolysis system as claimed in  claim 9 , further comprising:
 a return device that is connected to an outlet of the salt bridge compartment and an inlet of the cathode compartment, which is configured to recycle a reactant of the cathode reaction, which can be formed in the salt bridge compartment, back into the cathode compartment.   
     
     
         11 . A method for the electrolysis of CO 2  with an electrolysis cell as claimed in  claim 1 , the method comprising:
 reducing CO 2  at the cathode,   wherein hydrogencarbonate and/or carbonate generated at the cathode by the first ion exchange membrane migrates to an electrolyte in the salt bridge compartment,   wherein the hydrogencarbonate and/or carbonate is also transported through the solid anion exchanger in the salt bridge compartment away from the first ion exchange membrane.   
     
     
         12 . The method as claimed in  claim 11 ,
 wherein the salt bridge compartment comprises an aqueous electrolyte.   
     
     
         13 . The method as claimed in  claim 11 ,
 wherein the electrolyte of the salt bridge compartment comprises an acid, or a water-soluble acid, or a water-miscible acid.   
     
     
         14 . The method as claimed in  claim 11 ,
 wherein the electrolyte of the salt bridge compartment essentially comprises no mobile cations other than H +  and/or hydrated variants thereof.   
     
     
         15 . A method for the electrolysis of CO 2  and/or CO, the method comprising:
 performing electrolysis using the electrolysis cell as claimed in  claim 1 .   
     
     
         16 . The electrolysis cell as claimed in  claim 2 ,
 wherein the cations exchange hydrogencarbonate and/or carbonate ions.   
     
     
         17 . The electrolysis cell as claimed in  claim 4 ,
 wherein the uncharged particles, nonionic ion exchangers and/or cation exchangers are contained in an area adjacent to the first ion exchange membrane in an amount of up to 20 vol. %, based on the total amount of the solid anion exchanger and the uncharged particles, nonionic ion exchangers and/or cation exchangers.   
     
     
         18 . The electrolysis cell as claimed in  claim 4 ,
 wherein the uncharged particles and/or nonionic ion exchangers are contained in an area adjacent to the first ion exchange membrane in an amount of up to 20 vol. %, based on the total amount of the solid anion exchanger and the uncharged particles, nonionic ion exchangers and/or cation exchangers.