Dielectric barrier discharge plasma method and apparatus for synthesizing metal particles

Patent metadata

Field	Value
Publication number	US-10513790-B2
Application number	US-201515537279-A
Country	US
Kind code	B2
Filing date	Dec 15, 2015
Priority date	Dec 17, 2014
Publication date	Dec 24, 2019
Grant date	Dec 24, 2019

Abstract

A dielectric barrier discharge (DBD) plasma apparatus for synthesizing metal particles is provided. The DBD plasma apparatus includes an electrolyte vessel for receiving an electrolyte solution comprising metal ions; an electrode spaced-apart from the electrolyte vessel; a dielectric barrier interposed between the electrolyte vessel and the electrode such that, when the electrolyte solution is present in the electrolyte vessel, the dielectric barrier and an upper surface of the electrolyte solution are spaced-apart from each other and define a discharge area therebetween; and gas inlet and outlet ports in fluid communication with the discharge area such that supplying gas in the discharge area while applying an electrical potential difference between the electrode and the electrolyte solution cause a plasma to be produced onto the electrolyte solution, the plasma interacting with the metal ions and synthesizing metal particles. A method for synthesizing metal particles using a DBD plasma apparatus is also provided.

First claim

The invention claimed is:

1. A method for synthesizing metal particles, comprising:
providing a dielectric barrier discharge (DBD) plasma apparatus, the DBD plasma apparatus comprising an electrolyte vessel, an electrode spaced-apart from the electrolyte vessel, and a dielectric barrier interposed, in a planar configuration, between the electrolyte vessel and the electrode;
introducing an electrolyte solution comprising metal ions inside the electrolyte vessel, the electrolyte solution having an upper surface spaced-apart from the dielectric barrier;
supplying gas into a discharge area extending along and between the upper surface of the electrolyte solution and the dielectric barrier; and
applying, across the dielectric barrier, an alternating or pulsed direct electrical potential difference between the electrode and the electrolyte solution, the electrolyte solution acting as a counter-electrode polarized against the electrode, an amplitude of the electrical potential difference being sufficient to produce a plasma in the discharge area and onto the electrolyte solution so as to interact with the metal ions and thereby synthesize the metal particles.

2. The method according to claim 1 , wherein the supplying of the gas comprises continuously supplying the gas into the discharge area and evacuating gas therefrom.

3. The method according to claim 1 , wherein the introducing of the electrolyte solution further comprises conveying a flow of the electrolyte solution at least one time along an electrolyte flow path from an electrolyte inlet port to an electrolyte outlet port of the electrolyte vessel.

4. The method according to claim 3 , wherein the conveying of the flow of the electrolyte solution comprises conveying the flow of the electrolyte solution multiple times along the electrolyte flow path.

5. The method according to claim 1 , further comprising cooling the electrode.

6. The method according to claim 1 , wherein the electrode is a liquid electrode contained in an electrode cell, the method further comprising: continuously conveying a liquid of the liquid electrode in the electrode cell, and evacuating heat from the DBD plasma apparatus through the continuously conveyed liquid of the liquid electrode.

7. The method according to claim 6 , wherein at least a surface of the electrode cell is the dielectric barrier.

8. The method according to claim 1 , further comprising at least one of: monitoring and controlling a vertical gap between the upper surface of the electrolyte solution contained inside the electrolyte vessel and the dielectric barrier; monitoring a temperature of the electrolyte solution inside the electrolyte vessel and controlling the temperature of the electrolyte solution between about 0° C. and about 95° C.; and monitoring in real-time a spectral response of the synthesized metal particles.

9. The method according to claim 1 , further comprising grounding the electrolyte solution.

10. The method according to claim 1 , wherein the synthesized metal particles comprise Au, Pd, Pt, Ir, Os, Re, Ru, Rh, Ag, Ni, Cu, Fe, Mn, Co, or mixtures thereof.

11. The method according to claim 1 , wherein the metal ions comprise noble metal ions, transition metal ions, or mixtures thereof.

12. A dielectric barrier discharge (DBD) plasma apparatus for synthesizing metal particles, the DBD plasma apparatus comprising:
an electrolyte vessel for receiving an electrolyte solution comprising metal ions;
an electrode spaced-apart from the electrolyte vessel;
a dielectric barrier interposed, in a planar configuration, between the electrolyte vessel and the electrode such that, when the electrolyte solution is present in the electrolyte vessel in a synthesis region thereof, the dielectric barrier and an upper surface of the electrolyte solution in the synthesis region are spaced-apart from each other and define a discharge area extending therealong and therebetween; and
at least one gas inlet port and at least one outlet port in fluid communication with the discharge area such that, when the electrolyte solution is present in the electrolyte vessel, supplying gas in the discharge area while applying, using an electrical power source, an alternating or pulsed direct electrical potential difference across the dielectric barrier and between the electrode and the electrolyte solution, the electrolyte solution acting as a counter-electrode polarized against the electrode, cause a plasma to be produced in the discharge area and onto the electrolyte solution so as to interact with the metal ions and thereby synthesize the metal particles.

13. The DBD plasma apparatus according to claim 12 , wherein the upper surface of the electrolyte solution and the dielectric barrier extend parallel to and are separated from each other by a vertical gap when the electrolyte solution is contained in the electrolyte vessel, the vertical gap having a height of about 1 mm to about 10 mm.

14. The DBD plasma apparatus according to claim 12 , wherein the electrode is a liquid-based electrode comprising an electrically conductive liquid contained in at least one liquid containable cell.

15. The DBD plasma apparatus according to claim 14 , wherein the dielectric barrier is a bottom surface of the at least one liquid-containable cell.

16. The DBD plasma apparatus according to claim 15 , wherein the liquid-based electrode further comprises at least one electrically-conducting element connectable to the electrical power source to create the alternating or pulsed direct electrical potential difference, each one of the at least one electrically-conducting element being inserted in a respective one of the at least one liquid-containable cell.

17. The DBD plasma apparatus according to claim 12 , further comprising a ground for grounding the electrolyte solution contained in the electrolyte vessel.

18. The DBD plasma apparatus according to claim 12 , comprising a housing including a base and a removable mating cover, the base defining an electrolyte vessel receiving cavity and the electrolyte vessel being removably insertable in the electrolyte vessel receiving cavity of the housing, and wherein the at least one gas inlet port and the at least one gas outlet port extend through the housing and are in gas communication with the discharge area.

19. The DBD plasma apparatus according to claim 12 , further comprising at least one of:
a temperature control device including at least one temperature probe configured to monitor an electrolyte temperature, at least one of the temperature probe including a metal cladding in contact with the electrolyte solution contained in the electrolyte vessel and electrically grounding same to earth; and
a spectroscopy cell in fluid communication with the electrolyte vessel, mounted downstream of the electrolyte output port.

20. The DBD plasma apparatus according to claim 12 , wherein the electrolyte vessel is free of metallic electrode in contact with the electrolyte solution contained in the synthesis region.

21. The DBD plasma apparatus according to claim 12 , wherein the electrolyte vessel comprises an electrolyte inlet port, an electrolyte outlet port, the electrolyte solution being configured to flow along an electrolyte flow path between the electrolyte inlet and the electrolyte outlet.

22. The DBD plasma apparatus according to claim 21 , further comprising a pump inducing an electrolyte flow along the electrolyte flow path, an inlet tubing line in fluid communication with the electrolyte in

Assignees

• Univ Laval

Inventors

• Fortin Marc-André
• Bouchard Mathieu
• Sarra-Bournet Christian
• Turgeon Stéphane

Classifications

• B22F9/12

  starting from gaseous material · CPC title

• C25C7/00

  Constructional parts, or assemblies thereof, of cells; Servicing or operating of cells (for the production of aluminium C25C3/06 - C25C3/22) · CPC title

• B22F2999/00

  Aspects linked to processes or compositions used in powder metallurgy · CPC title

• B22F1/052

  characterised by a mixture of particles of different sizes or by the particle size distribution · CPC title

• B22F1/054

  Nanosized particles · CPC title