Electrochemical process for gas separation

A method of treating a gas stream, the method comprising:

• applying a first potential difference across at least one negative electrode and a positive electrode of an electrochemical cell, wherein the at least one negative electrode comprises a first electroactive species, the positive electrode comprises a second electroactive species, and the electrochemical cell comprises a separator positioned between the at least one negative electrode and the positive electrode, wherein the separator comprises:
• (a) a conductive electrolyte having a room temperature vapor pressure of less than 10−5 Pa;
• and/or
• (b) a room temperature ionic liquid;
• and
• introducing a gas stream comprising a target species comprising an aprotic acidic gas to the electrochemical cell to bond the target species to the first electroactive species to produce a treated gas stream;
• and
• applying a second, different potential difference across the at least one negative electrode and the positive electrode of the electrochemical cell to release the target species from the first electroactive species to produce a target species-rich gas stream;
• wherein:
• the application of the first potential difference causes a reduction reaction resulting in at least some of the first electroactive species being in a reduced state;
• the target species bonds to the first electroactive species in the reduced state to produce the treated gas stream;
• the application of the second potential difference causes an oxidation reaction at the at least one negative electrode resulting in the oxidation of at least some of the first electroactive species in the reduced state bonded to the target species;
• the target species is released from the oxidized first electroactive species to produce the target species-rich gas stream;
• and
• the first electroactive species comprises a quinone.