Methods and systems for carrying out a pH-influenced chemical and/or biological reaction

1. A system for carrying out a pH-influenced chemical and/or biological reaction, comprising:

a pH-adjustment zone comprising a solution and an electrode exposed to the solution, wherein at least 30% of the electrode by weight comprises a complexation agent capable of associating and/or disassociating an acid and/or base to and/or from the solution upon exposure to a first electrical potential; and

a reaction zone in fluid connection with the pH-adjustment zone, wherein the reaction zone comprises components and reagents for carrying out a pH-influenced chemical and/or biological reaction, wherein

the complexation agent is configured to reverse the association and/or disassociation of the acid and/or the base upon exposure to a second electrical potential, different than the first electrical potential.

2. The system of claim 1 , wherein the acid is a proton.

3. The system of claim 1 , wherein the base is a hydroxide.

4. The system of claim 1 , wherein the pH of the pH-selected solution is about 1, about 2, about 3, about 4, about 5, about 6, about 7, about 8, about 9, about 10, about 11, about 12, or about 13.

5. The system of claim 1 , wherein the pH-adjustment zone comprises a first electrode and a second electrode.

6. The system of claim 5 , wherein the first electrode is in a first compartment and the second electrode is in a second compartment.

7. The system of claim 6 , wherein the first compartment and the second compartment are separated by a membrane.

8. The system of claim 7 , wherein the membrane is an ion-selective membrane.

9. The system of claim 1 , wherein the pH-adjustment zone and the reaction zone comprise a first container and a second, different, container.

10. The system of claim 1 , wherein the pH-adjustment zone and the reaction zone are comprised in the same container.

11. The system of claim 1 , wherein the pH-influenced biological and/or chemical reaction involves the conversion of CO 2 to a dissolved species.

12. The system of claim 1 , wherein the change in pH of the solution is not due to water electrolysis.

13. The system of claim 1 , wherein the complexation agent is a solute in the solution.

14. The system of claim 1 , wherein the complexation agent is at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 98%, or at least 99%, of an electrode by weight.

15. The system of claim 1 , wherein the complexation agent is selected from the group consisting of:

PbSO 4 +2H 2 O⇔PbO 2 +SO 4 2− +4H + +2 e −

Cu+2OH − ⇔CuO+H 2 O+2 e −

Cu⇔Cu 2+ +2 e −

Cu 2+ +2OH − ⇔Cu(OH 2 )

Cu+2OH − ⇔Cu(OH) 2 +2 e −

2Cu+O 2 +H 2 O⇔2Cu(OH) 2 or

2Fe+O 2 +H 2 O⇔2Fe(OH) 2

16. The system of claim 1 , wherein the system comprises a first type of complexation agent and a second type of complexation agent.

17. A method, comprising:

providing a system comprising a pH-adjustment zone and a reaction zone in fluid connection with the pH-adjustment zone, wherein the pH-adjustment zone comprises an electrode, wherein at least 30% of the electrode by weight comprises a complexation agent and wherein the reaction zone comprises components and reagents for carrying out a pH-influenced chemical and/or biological reaction;

exposing the complexation agent in the pH-adjustment zone to a first electrical potential, wherein the complexation agent associates and/or disassociates an acid and/or base to and/or from the solution upon exposure to the first electrical potential and causes the pH of the solution to increase or decrease, thereby forming a pH-selected solution having a selected pH; and

flowing the pH-selected solution to the reaction zone, wherein the chemical and/or biological reaction is influenced by the pH of the pH-selected solution, and wherein the chemical and/or biological reaction causes the pH of the pH-selected solution to decrease or increase, wherein

the complexation agent is configured to reverse the association and/or disassociation of the acid and/or the base upon exposure to a second electrical potential, different than the first electrical potential.