# US 10,370,768 B2 · Catalysts for carbon dioxide conversion

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

- Number: US 10,370,768 B2
- Document ID: US10370768B2
- Status: Granted
- Kind: B2
- Application number: 14/392,120
- Filed: 2014-06-27
- Published: 2016-05-26
- Granted: 2019-08-06
- Earliest claimed: 2013-06-27
- Assignees: The Board of Trustees of the University of Illinois
- Applicants: The Board of Trustees of the University of Illinois
- Inventors: Amin Salehi-Khojin; Mohammad Asadi; Bijandra Kumar
- Web page: https://patentgrep.com/patent/US10370768B2

## CPC

- C25B 11/075: consisting of a single catalytic element or catalytic compound
- C25B 1/00: Electrolytic production of inorganic compounds or non-metals
- C25B 1/02: Hydrogen or oxygen
- C25B 1/23: Carbon monoxide or syngas
- C25B 3/07: Oxygen containing compounds
- C25B 3/25: Reduction
- C25B 3/26: of carbon dioxide
- 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)

## Abstract

The disclosure relates generally to improved methods for the reduction of carbon dioxide. The disclosure relates more specifically to catalytic methods for electrochemical reduction of carbon dioxide that can be operated at commercially viable voltages and at low overpotentials. The disclosure uses a transition metal dichalcogenide and helper catalyst in contact within the cell.

## Claims

### Claim 1

A method of electrochemically reducing carbon dioxide in an electrochemical cell having a cathode comprising at least one transition metal dichalcogenide, an electrolyte in contact with the cathode, and an anode, the method comprising
contacting the carbon dioxide with the at least one transition metal dichalcogenide of the cathode of the electrochemical cell, the electrolyte comprising at least one helper catalyst, each helper catalyst comprising at least one positively charged nitrogen, sulfur, or phosphorus group and
applying a potential to the electrochemical cell sufficient to reduce the carbon dioxide, wherein the transition metal dichalcogenide is in nanoflake, nanosheet, or nanoribbon form, the transition metal dichalcogenide nanoflakes, nanosheets, or nanoribbons having an average size between about 1 nm and 400 nm.

### Claim 2 (depends on 1)

A method of claim 1, wherein the transition metal dichalcogenide is selected from the group consisting of TiX2, VX2, CrX2, ZrX2, NbX2, MoX2, HfX2, WX2, TaX2, TcX2, and ReX2, wherein X is independently S, Se, or Te.

### Claim 3 (depends on 1)

A method of claim 1, wherein the transition metal dichalcogenide is MoS2 or MoSe2.

### Claim 4 (depends on 1)

A method of claim 1, wherein the transition metal dichalcogenide is in nanoflake form.

### Claim 5 (depends on 4)

A method of claim 4, wherein the transition metal dichalcogenide nanoflakes, nanosheets, or nanoribbons have an average size between about 50 nm and 400 nm.

### Claim 6 (depends on 1)

A method of claim 1, wherein the helper catalyst is an imidazolium, pyridinium, pyrrolidinium, phosphonium, ammonium, choline, sulfonium, prolinate, or methioninate salt.

### Claim 7 (depends on 1)

A method of claim 1, wherein the helper catalyst is an imidazolium salt, the imidazolium of the imidazolium salt having the formula:
wherein R1, R2, and R3 are independently selected from the group consisting of hydrogen, linear aliphatic C1-C6 group, branched aliphatic C1-C6 group and cyclic aliphatic C1-C6 group.

### Claim 8 (depends on 1)

A method of claim 1, wherein the helper catalyst is ethyl-3-methylimidazolium tetrafluoroborate.

### Claim 9 (depends on 1)

A method of claim 1, wherein the electrolyte is an aqueous solution.

### Claim 10 (depends on 9)

A method of claim 9, wherein the helper catalyst is present in the aqueous solution within the range from about 2 mol % to about 10 mol %.

### Claim 11 (depends on 1)

A method of claim 1, wherein the carbon dioxide is reduced to CO with a Faradaic efficiency of at least about 90%.

### Claim 12 (depends on 1)

A method of claim 1, wherein the applied potential is about −2 to about +2 V vs. reversible hydrogen electrode.

### Claim 13 (depends on 1)

A method of claim 1, wherein the reduction of carbon dioxide is initiated at overpotential of less than about 100 mV.

### Claim 14 (depends on 1)

A method of claim 1, wherein the reduction of carbon dioxide is at least about 90% Faradaic efficiency.

### Claim 15 (depends on 1)

A method of claim 1, wherein the transition metal dichalcogenide is vertically aligned.

### Claim 16 (depends on 1)

A method of claim 1, wherein the reduction of carbon dioxide is initiated at overpotential of less than about 100 mV and the carbon dioxide is reduced to CO with a Faradaic efficiency of at least about 90%.

### Claim 17 (depends on 1)

A method of claim 1, wherein the reduction of carbon dioxide is initiated at overpotential of less than about 100 mV and the reduction of carbon dioxide is at least about 90% Faradaic efficiency.

### Claim 18

An electrochemical cell having a cathode comprising at least one transition metal dichalcogenide, wherein the transition metal dichalcogenide is in nanoflake, nanosheet, or nanoribbon form, the transition metal dichalcogenide nanoflakes, nanosheets, or nanoribbons having an average size between about 1 nm and 400 nm, and an electrolyte comprising at least one helper catalyst comprising at least one positively charged nitrogen, sulfur, or phosphorus group in contact with the transition metal dichalcogenide.

### Claim 19 (depends on 18)

An electrochemical cell according to claim 18, wherein the transition metal dichalcogenide is MoS2.

### Claim 20 (depends on 18)

An electrochemical cell according to claim 18, wherein the helper catalyst is present in an amount of about 4 mol % to about 10 mol %.

### Claim 21 (depends on 18)

An electrochemical cell according to claim 18, wherein the helper catalyst is ethyl-3-methylimidazolium salt tetrafluoroborate.

### Claim 22 (depends on 18)

An electrochemical cell of claim 18, wherein the helper catalyst is an imidazolium, pyridinium, pyrrolidinium, phosphonium, ammonium, choline, sulfonium, prolinate, or methioninate salt.