Method for preparing a catalytic material of an electrode for electrochemical reduction reactions prepared by electroreduction

Patent metadata

Field	Value
Publication number	US-2022018033-A1
Application number	US-201917295775-A
Country	US
Kind code	A1
Filing date	Nov 19, 2019
Priority date	Nov 30, 2018
Publication date	Jan 20, 2022
Grant date	—

Abstract

A method for preparing a catalytic material of an electrode for electrochemical reduction reactions, which comprises: a) a step of electrolysis of at least one aqueous and/or organic solution comprising at least one precursor of the active phase comprising at least one group VIB metal in order to obtain a solution comprising at least one precursor comprising at least one group VIB metal which has been partially reduced; b) a step of impregnation of said support with said solution obtained in step a) in order to obtain a catalytic material precursor; c) a step of drying said precursor obtained in step b) at a temperature below 250° C., without subsequent calcination; d) a step of sulfurization of the catalytic material precursor obtained in step c) at a temperature of between 100° C. and 600° C.

First claim

1 . A process for the preparation of a catalytic material of an electrode for electrochemical reduction reactions, said material comprising at least one active phase based on a metal from group VIb and an electroconductive support, which process comprises at least the following stages:
a) a stage of electrolysis of at least one aqueous and/or organic solution comprising at least one precursor of the active phase comprising at least one metal from group VIb, in order to obtain a solution comprising at least one precursor comprising at least one partially reduced metal from group VIb; b) a stage of impregnation of said support with said solution obtained in stage a), in order to obtain a catalytic material precursor; c) a stage of drying said precursor obtained in stage b) at a temperature of less than 250° C., without subsequent calcination; d) a stage of sulfurization of the catalytic material precursor obtained in stage c) at a temperature of between 100° C. and 600° C.

2 . The process as claimed in claim 1 , in which stage a) is carried out in an electrolyzer comprising at least two electrochemical compartments separated by a membrane or a porous separator and respectively including one the anode and the other the cathode.

3 . The process as claimed in claim 1 , in which the current density applied in stage a) is between 5 and 500 mA/cm 2 .

4 . The process as claimed in claim 1 , in which said precursor comprising at least one metal from group VI is chosen from polyoxometallates corresponding to the formula (H h X x M m O y ) q− in which X is an element chosen from phosphorus (P), silicon (Si), boron (B), nickel (Ni) or cobalt (Co), M is one or more metal(s) chosen from molybdenum (Mo), tungsten (W), nickel (Ni), cobalt (Co) and iron (Fe), 0 being oxygen, h being an integer between 0 and 12, x being an integer between 0 and 4, m being an integer equal to 5, 6, 7, 8, 9, 10, 11, 12 and 18, y being an integer between 17 and 72 and q being an integer between 1 and 20, it being understood that M is not a nickel atom or a cobalt atom alone.

5 . The process as claimed in claim 4 , in which the m atoms M are either only molybdenum (Mo) atoms, or only tungsten (W) atoms, or a mixture of molybdenum (Mo) and tungsten (W) atoms, or a mixture of molybdenum (Mo) and cobalt (Co) atoms, or a mixture of molybdenum (Mo) and nickel (Ni) atoms, or a mixture of tungsten (W) and nickel (Ni) atoms.

6 . The process as claimed in claim 4 , in which the m atoms M are either a mixture of nickel (Ni), molybdenum (Mo) and tungsten (W) atoms or a mixture of cobalt (Co), molybdenum (Mo) and tungsten (W) atoms.

7 . The process as claimed in claim 1 , in which at least one precursor of the active phase comprising at least one metal from group VIII is introduced, said precursor being brought into contact with the electroconductive support by impregnation, either:
i) before stage b) of impregnation of said support with the solution obtained in stage a), in a “preimpregnation” stage b1) using a solution comprising at least one precursor of the active phase comprising at least one metal from group VIII; ii) during the impregnation stage b), in coimpregnation with said solution comprising at least one precursor of the active phase comprising at least one partially reduced metal from group VIb obtained in stage a); iii) after the drying stage c), in a “postimpregnation” stage b2), using a solution containing at least one precursor of the active phase comprising at least one metal from group VIII; iv) after the sulfurization stage c), in a “postimpregnation” stage b3) using a solution comprising at least one precursor of the active phase comprising at least one metal from group VIII.

8 . The process as claimed in claim 7 , in which said metal from group VIII is chosen from nickel, cobalt and iron.

9 . The process as claimed in claim 1 , in which, when said precursor of the catalytic material comprises at least one metal from group VIb and at least one metal from group VIII, the sulfurization temperature is between 350° C. and 550° C.

10 . The process as claimed in claim 1 , in which, when said precursor of the catalytic material solely comprises only at least one metal from group VIb, the sulfurization temperature is between 100° C. and 250° C. or between 400° C. and 600° C.

11 . The process as claimed in claim 1 , in which said electroconductive support comprises at least one material chosen from carbon structures of carbon black, graphite, carbon nanotubes or graphene type.

12 . The process as claimed in claim 1 , in which said electroconductive support comprises at least one material chosen from gold, copper, silver, titanium or silicon.

13 . An electrode, characterized in that it is formulated by a preparation process comprising the following stages:
1) at least one ionic conductive polymer binder is dissolved in a solvent or a solvent mixture; 2) at least one catalytic material prepared according to claim 1 , in powder form, is added to the solution obtained in stage 1) in order to obtain a mixture; stages 1) and 2) being carried out in any order or simultaneously; 3) the mixture obtained in stage 2) is deposited on a metallic or metallic-type conductive support or collector.

14 . An electrolysis device comprising an anode, a cathode and an electrolyte, said device being characterized in that one at least of the anode or of the cathode is an electrode as claimed in claim 13 .

15 . A method comprising performing an electrochemical reaction with the electrolysis device as claimed in claim 14 .

16 . A method as in claim 15 , wherein said electrolysis device is used as:
a water electrolysis device for the production of a gaseous mixture of hydrogen and oxygen and/or the production of hydrogen alone; a carbon dioxide electrolysis device for the production of formic acid; a nitrogen electrolysis device for the production of ammonia; a fuel cell device for the production of electricity from hydrogen and oxygen.

Assignees

• Ifp Energies Now

Inventors

• Bonduelle-Skrzypczak Audrey
• Belaid Sofiane
• Pasquier David
• Trela-Baudot Emmanuelle

Classifications

• C25B1/044

  producing mixed hydrogen and oxygen gas, e.g. Brown's gas [HHO] · CPC title

• C25B11/057

  consisting of a single element or compound · CPC title

• C25B1/04 Primary

  by electrolysis of water · CPC title

• C25B13/00

  Diaphragms; Spacing elements · CPC title

• Y02E60/50

  Fuel cells · CPC title