# US 2018/0023203 A1 · Filter-press photoelectrochemical water oxidation and co2 reduction cell

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2018/0023203 A1
- Document ID: US20180023203A1
- Status: Published application
- Kind: A1
- Application number: 15/537,046
- Filed: 2015-12-18
- Published: 2018-01-25
- Earliest claimed: 2014-12-19
- Assignees: Repsol, S.A.; Enagas Services Solutions, S.L.U.
- Applicants: Repsol, S.A.
- Inventors: María Dolores HERNÁNDEZ ALONSO; Germán PENELAS PÉREZ; Tresa ANDREU; Erdem IRTEM; Andrés PARRA; Cristián FÁBREGA; Juan Ramón MORANTE
- Web page: https://patentgrep.com/patent/US20180023203A1

## CPC

- C25B 9/73: of the filter-press type
- B01J 23/38: of noble metals
- B01J 23/70: of the iron group metals or copper
- C01B 32/50: Carbon dioxide
- C25B 1/00: Electrolytic production of inorganic compounds or non-metals
- C25B 1/01: Products
- C25B 1/04: by electrolysis of water
- C25B 1/23: Carbon monoxide or syngas
- C25B 1/55: Photoelectrolysis
- C25B 9/50: Cells or assemblies of cells comprising photoelectrodes; Assemblies of constructional parts thereof
- Y02E 60/36: Hydrogen production from non-carbon containing sources, e.g. by water electrolysis
- Y02P 20/133: Renewable energy sources, e.g. sunlight
- C25B: ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR (anodic or cathodic protection C23F13/00; single-crystal growth C30B)
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C}
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS

## Abstract

The present disclosure relates to methods and devices for use in photoelectrochemical reduction of CO2. In particular, it is disclosed a filter-press photoelectrochemical cell for producing a reduction product from CO2 and a method for the photoelec-trochemical reduction of CO2.

## Claims

### Claim 1

A filter-press photoelectrochemical cell comprising:
a) a cathodic compartment (1) which comprises a cathode support frame (150) comprising a cathodic material (4) which acts as a cathode; a first fluid and gaseous CO2 distribution frame (6) and a second fluid and gaseous CO2 distribution frame (7); one or more cathodic gaskets (81, 82, 83 and 84) , the cathodic gaskets being placed between the cathode support frame (150) and the distribution frames (6, 7), and as lateral ends of the cathodic compartment; wherein the cathode support frame (150) is disposed between the first and second distribution frames (6; 7);
b) an anodic compartment (2) which comprises an anode support frame (250) comprising an anodic material (5) which acts as an anode; a fluid distribution frame (8) arranged such that the fluid distribution frame (8) is on a portion of the anodic compartment closer to the membrane (3) than the anode support frame (250); and one or more anodic gaskets (85 and 86), the anodic gaskets being placed between the anode support frame (250) and the distribution frame (8), and as lateral ends of the anodic compartment; and
c) an ion-exchange membrane (3) disposed between the cathodic compartment (1) and the anodic compartment (2);
wherein
i) the cathodic material (4) is a conductive porous electrode with immobilized CO2 electrocatalyst material;
ii) the first and second fluid and gaseous CO2 distribution frames (6, 7) and cathodic gaskets (81, 82, 83 and 84) are arranged such that in use they allow introducing a catholyte and gaseous CO2 separately into the cathodic compartment (1) through different inlet ports (11a, 11b) and they allow exiting the catholyte, liquid and gaseous products and/or unreacted CO2 jointly through an outlet port (12);
iii) the fluid distribution frame (8), the anode support frame (250) and anodic gaskets (85 and 86) are arranged in such a way that in use they allow introducing an anolyte into the anodic compartment (2) through an inlet port (13), and they allow exiting the anolyte and oxidation products jointly through an outlet port (14);
iv) the anodic material (5), is a photocatalytic anodic material, and is located in a side facing the membrane (3) of an optical window (15) of the anode support frame (250); and is arranged such that in use is able to be in contact with the anolyte which is introduced into the anodic compartment via the inlet port (13) and, is able to be activated when the radiation used to irradiate the anodic compartment (2) reaches the optical window (15) by its opposite side which is not facing the membrane (3); and
v) the photocatalytic anodic material (5) and the gas diffusion cathodic material (4) have a surface area ratio comprised from 1:1 to 1:0.1.

### Claim 2 (depends on 1)

The filter-press photoelectrochemical cell according to claim 1, wherein the immobilized CO2 electrocatalyst material of the cathodic material (4) is selected from
a) a metal with a high overpotential to hydrogen evolution, low CO adsorption and high overpotential for CO2 to CO2 radical ion; selected from the group consisting of Pb, Hg, In, Sn, Cd, Tl and Bi;
b) a metal with a medium overpotential to hydrogen evolution and low CO adsorption; selected from the group consisting of Au, Ag, Zn, Pd and Ga;
c) a metal with a high CO adsorption and a medium overpotential to hydrogen evolution; selected from the group consisting of Cu;
d) a metal with a relatively low overpotential to hydrogen evolution and a high CO adsorption, selected from the group consisting of Ni, Fe, Pt, Ti;
e) an oxide of any of the metals of a), b), c) or d) type; and
f) combinations thereof;
the material being deposited on a highly porous and conductor support.

### Claim 3 (depends on 1)

The filter-press photoelectrochemical cell according claim 1, wherein the immobilized CO2 electrocatalyst material of the cathodic material (4) is selected from the group consisting of Sn, Pb, Hg, Bi, In, Cd, Tl, Cu, CuO, Cu2O, Au, Ag, Zn, Pd, Ga and combinations thereof, the materials deposited on a highly porous and conductor support.

### Claim 4 (depends on 1)

The filter-press photoelectrochemical cell according to claim 1, wherein the immobilized CO2 electrocatalyst material of the cathodic material (4) is selected from the group consisting of Pb, Hg, In, Sn, Cd, Tl, Bi and combinations thereof, the materials deposited on a highly porous and conductor support.

### Claim 5 (depends on 1)

The filter-press photoelectrochemical cell according to claim 1, wherein the highly porous and conductor support is selected from carbon paper, carbon based nanofibres, metallic meshes, and metal foams.

### Claim 6 (depends on 1)

The filter-press photoelectrochemical cell according to claim 1, wherein the photocatalytic anodic material (5) is selected from semiconductor materials with a bandgap between 1.1 and 3.4 eV and valence band edge equal to or higher than 1.23V vs RHE.

### Claim 7 (depends on 6)

The filter-press photoelectrochemical cell according to claim 6, wherein the photocatalytic anodic material (5) is selected from the group consisting of TiO2, WO3, BiVO4, Fe2O3, SrTiO3, Si, amorphous Si, GaAs, GaN, MoS2, WSe2, MoSe2 and combinations thereof

### Claim 8 (depends on 1)

The filter-press photoelectrochemical cell according to claim 1, wherein the anolyte comprises
a) at least one polar protic solvent comprising at least one supporting electrolyte, and
b) optionally a buffer solution;
the supporting electrolyte is a salt of the formula MmYr, in which M is selected from lithium, potassium, sodium, magnesium, calcium, and strontium; Y is either a hydroxide ion or a counter ion coming from mineral acids selected from halides, sulfates, nitrates, chlorates or phosphates.

### Claim 9 (depends on 8)

The filter-press photoelectrochemical cell according to claim 8, wherein the salt included as a supporting electrolyte is selected from NaOH, KOH, H2SO4, KCl, HCl, H3PO4, NaHCO3, K2HPO4, K2SO4, Na2SO4.

### Claim 10 (depends on 1)

The filter-press photoelectrochemical cell according to claim 1, wherein the catholyte comprises
a) at least one polar protic solvent comprising at least one supporting electrolyte, and
b) optionally a buffer solution;
the supporting electrolyte is a salt of the formula MmXn in which: M is selected from magnesium, calcium, lithium, potassium and sodium; X is selected from anions of weak or strong acids selected from carbonates, bicarbonates, sulfates, hydroxides and halides.

### Claim 11 (depends on 10)

The filter-press photoelectrochemical cell according to claim 10, wherein the salt included as a supporting electrolyte is selected from NaHCO3, KHCO3, K2CO3, Na2SO4, K2SO4, KCl, KClO4.

### Claim 12 (depends on 1)

The filter-press photoelectrochemical cell according to claim 1, wherein the ion-exchange membrane is an ion-exchange membrane that permits selected ions to cross the membrane to balance the process stoichiometry.

### Claim 13 (depends on 1)

The filter-press photoelectrochemical cell according to claim 1, wherein the ion-exchange membrane is a cation exchange membrane.

### Claim 14 (depends on 1)

A method for reducing carbon dioxide comprising the steps of:
i) providing an filter-press photoelectrochemical cell as defined in claim 1;
ii) feeding the filter-press photoelectrochemical cell with an anolyte through an inlet port (13) into the anodic compartment (2), a catholyte through an inlet port (11a) into the cathodic compartment (1) and a gas containing CO2 through a different inlet port (11b) into the cathodic compartment (1);
iii) applying to the cell an external electrical potential between cathode (4) and anode (5) with bias capacity ranging from 0 to 4 volts;
iv) irradiating the photoanode with a radiation, thus radiation incides on the optical window (15) activating the photocatalytic anodic material (5) by its opposite side which is not facing the membrane (3); and
v) collecting the products of the cathodic reaction from the cathodic compartment outlet (12) for identification and quantification.

### Claim 15 (depends on 14)

The method according to claim 14 wherein the irradiating step is carried out using solar radiation or an artificial UV-V is radiation source.