Method for electrochemical ammonia synthesis using single-crystalline metal catalyst

Patent metadata

Field	Value
Publication number	US-2019161872-A1
Application number	US-201715846893-A
Country	US
Kind code	A1
Filing date	Dec 19, 2017
Priority date	Nov 24, 2017
Publication date	May 30, 2019
Grant date	—

Abstract

An electrochemical method for ammonia synthesis including the steps of: preparing a single-crystalline metal thin film; and synthesizing ammonia by using the single-crystalline metal thin film electrode. More particularly, it relates to improvement of the production yield and synthesis rate of ammonia trough the method for preparing ammonia by using an electrochemical reactor which includes a cathode including a single-crystalline metal thin film on the surface thereof, an anode and an electrolyte, wherein the method includes the steps of: supplying nitrogen to the cathode; supplying aqueous electrolyte solution to the anode; and applying an electric voltage between the cathode and the anode.

First claim

What is claimed is:

1 . An electrochemical reactor for ammonia synthesis which comprises a cathode, an anode and an electrolyte,
wherein the cathode comprises a single-crystalline metal thin film on the surface thereof.

2 . The electrochemical reactor for ammonia synthesis according to claim 1 , wherein the metal is Cu, Ag, Al or an alloy of two or more of them.

3 . The electrochemical reactor for ammonia synthesis according to claim 1 , wherein the single-crystalline metal thin film has a root-mean square roughness of 0.1-3 nm, as analyzed by atomic force microscopy (AFM).

4 . The electrochemical reactor for ammonia synthesis according to claim 1 , wherein the single-crystalline metal thin film has a thickness of 50-300 nm.

5 . The electrochemical reactor for ammonia synthesis according to claim 1 , wherein only (111) crystal surfaces are observed in the single-crystalline metal thin film, after analyzing it by X-ray diffractometry (XRD) in a specific direction.

6 . A method for preparing a catalyst for electrochemical ammonia synthesis which comprise step (B) of growing a single-crystalline metal epitaxially on a plate-like single-crystalline mica substrate.

7 . The method for preparing a catalyst for electrochemical ammonia synthesis according to claim 6 , wherein step (B) is carried out at a deposition temperature of 100-600° C. under a deposition rate of 1-3 nm/s.

8 . The method for preparing a catalyst for electrochemical ammonia synthesis according to claim 6 , which further comprises a step of heat treating the single-crystalline mica substrate, before step (B).

9 . The method for preparing a catalyst for electrochemical ammonia synthesis according to claim 6 , which further comprises, after step (B), step (A) of heating the single-crystalline mica substrate including epitaxially grown single-crystalline metal at the above-defined deposition temperature for 1-60 minutes.

10 . A method for preparing ammonia by using an electrochemical reactor which comprises a cathode comprising a single-crystalline metal thin film on the surface thereof, an anode and an electrolyte, the method comprising the steps of:
(A) supplying nitrogen to the cathode; (B) supplying aqueous electrolyte solution to the anode; and (C) applying an electric voltage between the cathode and the anode.

11 . The method for preparing ammonia by using an electrochemical reactor according to claim 10 , wherein the anode is a titanium or carbon rod coated with at least one oxide of metal selected from iridium, ruthenium and cobalt.

12 . The method for preparing ammonia by using an electrochemical reactor according to claim 10 ,
wherein nitrogen is supplied at a rate of 150-250 mL/minute, aqueous electrolyte solution is supplied at a rate of 0.5-5 mL/minute, and the electric potential is applied to cathode at 0.1 to −1.0 V vs. the reference hydrogen generation potential.

Assignees

• Korea Inst Sci & Tech

Inventors

• Park Jong Hyuk
• Park Hyun Seo
• Kong Jimin

Classifications

• C30B23/025

  characterised by the substrate · CPC title

• C30B33/02

  Heat treatment (C30B33/04, C30B33/06 take precedence) · CPC title

• C25B11/02

  characterised by shape or form · CPC title

• C25B1/00

  Electrolytic production of inorganic compounds or non-metals · CPC title

• C30B29/02

  Elements · CPC title