Back to results
US 9,145,615 B2Granted
Method and apparatus for the electrochemical reduction of carbon dioxide
OwnerYumei Zhai, Shan Guan +2inventors
InventorsYumei Zhai, Shan Guan, Narasi Sridhar, Arun S. Agarwal
Life of this patent
Estimating the term…
Abstract
A method and apparatus is provided for the electrochemical reduction of carbon dioxide to formate and formic acid. One embodiment features a three-compartment reactor which houses: a gas compartment; a catholyte compartment, which contains a porous cathode having a tin-based catalyst; and an anolyte compartment, which contains an anode having a mixed metal oxide catalyst. Further embodiments include a method for depositing tin onto a porous cathode, tin-zinc cathodes, a reaction method using an acidic anolyte, and pulsed polarization to extend reactor runtimes.
Claims21
An apparatus for the electrochemical reduction of carbon dioxide to formate, comprising:
- a container;
- a membrane, the membrane positioned within the container, the membrane dividing the container into a catholyte compartment and an anolyte compartment;
- an anode, the anode comprising:
- a titanium substrate;
- and
- a metal oxide catalyst, the metal oxide catalyst comprising:
- tantalum oxide deposited onto the substrate;
- and
- iridium oxide deposited onto the tantalum oxide, the anode positioned at least partially within the anolyte compartment;
- a cathode-and-pad combination, the cathode-and-pad combination comprising:
- a porous cathode, the porous cathode comprising:
- a porous substrate;
- and
- a coating, the coating selected from the group consisting of:
- (I) tin;
- and
- zinc, the zinc comprising between about three weight percent and about six weight percent of the coating;
- and
- (II) tin, the tin deposited onto the substrate, the tin comprising tin deposits having a grain size of between 0.5 microns and five microns, the tin deposits substantially covering the catholyte compartment side surface of the substrate, the tin deposited by a process comprising:
- (a) immersing the porous substrate into a solution comprising:
- stannous chloride dihydrate;
- at least one complexing agent selected from the group consisting of:
- (i) tetrapotassium pyrophosphate;
- and
- (ii) glycine;
- and
- (iii) combinations thereof;
- and
- a non-ionic surfactant;
- and
- (b) during step (a):
- (i) maintaining the solution at a temperature of between 45 and 70 deg. C;
- and
- (ii) applying a cathodic current density of 1.5 to 2.5 mA/cm2 for between 0.5 and two hours;
- and
- a porous, nonconductive pad, the pad positioned adjacent to the membrane side of the cathode, the cathode-and-pad combination and the membrane at least partially defining the catholyte compartment;
- a gas compartment, the gas compartment in fluid communication with the cathode;
- and
- a voltage source, the voltage source in electrical communication with the anode and with the cathode, the voltage source configured to impress a DC voltage across the anode and the cathode.
36 more elements
A process for reducing carbon dioxide, comprising:
- (a) introducing an anolyte into an anolyte compartment of an electrochemical reactor, the anolyte compartment at least partially containing an anode;
- (b) introducing a catholyte into a catholyte compartment of the electrochemical reactor, the catholyte compartment separated from the anolyte compartment by a membrane, the catholyte compartment further separated from a gas compartment by a cathode-and-pad combination, the cathode-and-pad combination comprising:
- a porous cathode;
- and
- a porous, nonconductive pad, the pad positioned adjacent to the membrane side of the cathode, the cathode-and-pad combination and the membrane at least partially defining the catholyte compartment;
- (c) introducing carbon dioxide gas into the gas compartment;
- (d) introducing carbon dioxide gas from the gas compartment into the cathode;
- (e) introducing the carbon dioxide gas from the cathode into the catholyte;
- and
- (f) impressing a DC voltage across the anode and the cathode.
7 more elements
An apparatus, comprising:
- an anolyte compartment, the anolyte compartment at least partially defined by an anode and a membrane;
- a catholyte compartment, the catholyte compartment at least partially defined by a cathode-and-pad combination, the cathode-and-pad combination comprising:
- a porous cathode;
- and
- a porous, nonconductive pad, the pad positioned adjacent to the membrane side of the cathode;
- a catholyte feed in fluid communication with the catholyte compartment;
- a gas compartment, the gas compartment in fluid communication with the cathode;
- and
- a voltage source, the voltage source in electrical communication with the anode and with the cathode, the voltage source configured to impress a DC voltage across the anode and the cathode.
6 more elements
Dependencies are inferred from the claim text.