Electrolyzers for the reduction of carbon dioxide to formate
The present disclosure relates to an electrochemical flow cell that includes a gap positioned between an ion exchange membrane (IEM) and a cathode gas diffusion electrode (GDE), where the gap is positioned to contain a liquid and the gap has a thickness value, as defined by the distance between the IEM and the cathode GDE, of between greater than zero mm and less than about 2.0 mm. In some embodiments of the present disclosure, the gap may be between about 0.1 mm and about 1.0 mm.
1. An electrochemical flow cell configured for the reduction of carbon dioxide, the electrochemical flow cell comprising:
a first gap positioned between an ion exchange membrane (IEM) and a cathode gas diffusion electrode (GDE), and
a cathode flow plate, wherein:
the cathode GDE is positioned between the IEM and the cathode flow plate,
the cathode flow plate comprises a serpentine flow path,
the first gap is configured to contain a liquid, and
the first gap has a width value, as defined by the distance between the IEM and the cathode GDE, of between about 0.1 mm and about 2.0 mm.
2. The electrochemical flow cell of claim 1 , wherein the width is between about 0.1 mm and about 1.0 mm.
3. The electrochemical flow cell of claim 1 , wherein the first gap, when filled with the liquid, provides a conductivity of greater than about 5 S/m.
4. The electrochemical flow cell of claim 1 , further comprising at least two contacts configured to estimate a voltage drop across the electrochemical cell.
5. The electrochemical flow cell of claim 1 , wherein:
the cathode flow plate further comprises a first inlet and a first outlet, and
the serpentine flow path fluidly connects the first inlet and the first outlet.
6. The electrochemical flow cell of claim 5 , wherein:
the serpentine flow path comprises three or more channels positioned substantially parallel relative to each other, and
the channels are configured to maximize contact of the carbon dioxide with a maximum amount of area of the cathode GDE.
7. The electrochemical flow cell of claim 6 , wherein:
each channel comprises a section comprising:
a first portion which traverses across a first dimension of the cathode flow plate;
a second portion which crosses a portion of a second dimension of the cathode flow plate, and
a third portion which traverses across the first dimension of the cathode flow plate, wherein:
the first dimension is substantially perpendicular to the second dimension,
when in the first portion, the carbon dioxide flows in a first direction, and
when in the third portion, the carbon dioxide flows in a second direction that is substantially opposite to the first direction.
8. The electrochemical flow cell of claim 7 , wherein:
each channel comprises two or more sections, and
each section is connected in series to the remaining sections.
9. The electrochemical flow cell of claim 1 , further comprising:
a baffled gasket, and
the cathode flow plate further comprises a second inlet and a second outlet, wherein:
the baffled gasket is positioned between the IEM and the cathode GDE,
the baffled gasket forms a second gap between the IEM and the cathode GDE, and
the second inlet and the second outlet are fluidly connected by the second gap.
10. The electrochemical flow cell of claim 1 , wherein the cathode GDE comprises an anion exchange ionomer.
11. The electrochemical flow cell of claim 1 , wherein the electrochemical flow cell is configured to convert the carbon dioxide to formate.