ELECTROCHEMICAL CELL INCLUDING PH DIFFERENTIAL
An electrochemical cell comprises an anode, an anode electrolyte solution in contact with the anode, wherein the anode electrolyte solution has a first pH, a cathode comprising an ionomer, a cathode electrolyte solution in contact with the cathode wherein the cathode electrolyte solution has a second pH, and a separator positioned between the anode and the cathode, wherein the electrochemical cell is configured to maintain a pH differential between the first pH and the second pH.
1 . An electrochemical cell comprising:
an anode;
an anode electrolyte solution in contact with the anode, wherein the anode electrolyte solution has a first pH;
a cathode comprising an ionomer;
a cathode electrolyte solution in contact with the cathode wherein the cathode electrolyte solution has a second pH; and
a separator positioned between the anode and the cathode;
wherein the electrochemical cell is configured to maintain a pH differential between the first pH and the second pH.
2 . The electrochemical cell of claim 1 , wherein the cathode comprises a substrate coated with a catalyst coating, wherein the catalyst coating comprises the ionomer.
3 . The electrochemical cell of claim 2 , wherein the catalyst coating comprises particles of catalyst material and a binder that binds the particles of catalyst material to the substrate, wherein the binder comprises the ionomer.
4 . The electrochemical cell of claim 1 , wherein the ionomer comprises a fluoropolymer-based polymer with one or more ionic group modifications.
5 . The electrochemical cell of claim 4 , wherein the ionomer comprises a polytetrafluoroethylene backbone modified with one or more ionic groups.
6 . The electrochemical cell of claim 5 , wherein the one or more ionic groups comprise one or more perfluorovinyl ether groups and one or more sulfonate groups.
7 . The electrochemical cell of claim 1 , wherein the ionomer comprises NAFION.
8 . The electrochemical cell of claim 1 , wherein the pH differential is a steady-state pH differential between the first pH and the second pH.
9 . The electrochemical cell of claim 1 , wherein the first pH is higher than the second pH.
10 . The electrochemical cell of claim 1 , wherein the first pH of the anode electrolyte solution is from about 14 to about 16.
11 . The electrochemical cell of claim 1 , wherein the second pH of the cathode electrolyte solution is from about 7 to about 15.
12 . The electrochemical cell of claim 1 , wherein an absolute value of the pH differential is from about 1 to about 10.
13 . The electrochemical cell of claim 1 , wherein an absolute value of the pH differential is from about 1 to about 4.
14 . The electrochemical cell of claim 1 , wherein the separator comprises at least one of: an anion exchange membrane, a porous separator, and an ion solvating separator.
15 . A method of electrolysis, the method comprising:
providing an electrochemical cell comprising a separator having a first side and an opposing second side, am anode positioned on the first side of the separator, and a cathode comprising an ionomer positioned on the second side of the separator;
contacting the anode with an anode electrolyte solution having a first pH;
contacting the cathode with a cathode electrolyte solution having a second pH;
maintaining a pH differential between the first pH and the second pH;
passing current between the anode and the cathode; and
producing hydrogen gas (H 2 ) at the cathode.
16 . The method of claim 15 , wherein the cathode comprises a substrate coated with a catalyst coating, wherein the catalyst coating comprises the ionomer.
17 . The method of claim 16 , wherein the catalyst coating comprises particles of catalyst material and a binder that binds the particles of catalyst material to the substrate, wherein the binder comprises the ionomer.
18 . The method of claim 15 , wherein the ionomer comprises a fluoropolymer-based polymer with one or more ionic group modifications.
19 . The method of claim 18 , wherein the ionomer comprises a polytetrafluoroethylene backbone modified with one or more ionic groups.
20 . The method of claim 19 , wherein the one or more ionic groups comprise one or more perfluorovinyl ether groups and one or more sulfonate groups.
21 . The method of claim 15 , wherein the ionomer comprises NAFION.
22 . The method of claim 15 , wherein maintaining the pH differential comprises maintaining a steady-state pH differential between the first pH and the second pH.
23 . The method of claim 15 , wherein the first pH of the anode electrolyte solution is from about 8 to about 16.
24 . The method of claim 15 , wherein the second pH of the cathode electrolyte solution is from about 7 to about 15.
25 . The method of claim 15 , wherein an absolute value of the pH differential is from about 1 to about 4.