A method for preparing a bis-carbon alkane compound

Abstract

The application discloses a copper-gallium alloy, wherein the mass percentage of gallium in the copper-gallium alloy is 3% to 10%. The copper-gallium alloy can be used as a cathode electrode for electro-reducing carbon dioxide after being subjected to rapid electro-reduction treatment, and is used for preparing ethane. In the application, the addition of Ga element enables the copper alloy sheet to electrocatalytically reduce carbon dioxide to prepare ethane at a low potential, and a new technical route is provided for subsequent industrialization of electrocatalytic reduction of carbon dioxide.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of electrocatalytic reduction of carbon dioxide, and particularly relates to a method for preparing ethane by electrocatalytic reduction of carbon dioxide at a low potential using a Cu-Ga alloy. BACKGROUND

[0002] The process of electrocatalytic reduction of carbon dioxide is essentially that carbon dioxide obtains electrons on the surface of a cathode and combines with various ions (OH- and H+, etc.) in an electrolyte to form various products such as CO, HCOOH, CH4, etc., and this process is also an important way for carbon dioxide to be reused. Catalysts can be divided into metal materials and non-metal materials. Metal electrode cathode materials can be mainly divided into four categories: the first category is represented by Au, Ag, Zn, Ga, etc., and the main product is CO; the second category is represented by Pb, Hg, In, etc., and the main product is HCOOH; the third category is represented by Ni, Fe, Pt, etc., and the main product is H2; and the fourth category is represented only by Cu, which can produce C1 type products as well as C2 and C3 products. However, the selectivity and efficiency of products prepared by electrocatalytic reduction of carbon dioxide using a single metal are low, and cannot meet the demand for producing a large amount of products in production.

[0003] At present, there have been many reports on the research of cathode materials for electro-reduction of carbon dioxide, including Cu foam, Cu-Sn alloy, Cu-Zn alloy, etc., which are surface-modified by a simple heat treatment-electro-reduction process, so that the alloy sheet has a rough surface with different morphologies, thereby obtaining a high-efficiency cathode material for electrocatalytic reduction of carbon dioxide. However, there are few reports on the research of Cu-Ga alloy, a kind of bimetallic cathode electrode, by the heat treatment-electro-reduction process. Secondly, in the current literature reports, the products prepared by the electro-reduction of carbon dioxide by Cu foam, Cu-Zn alloy and Cu-Sn alloy are CO, CH4 and HCOOH, etc., and there are few literature reports on alloy cathode materials capable of preparing ethane. SUMMARY

[0004] In view of the lack of research on the electrocatalytic reduction of carbon dioxide at a low potential by Cu-Ga alloy to prepare ethane, the application prepares a Cu-Ga alloy by vacuum arc melting of pure Cu and pure Ga, and processes the surface of the alloy under different heat treatment-electro-reduction conditions to obtain nanoparticles or nanoclusters on the surface, thereby improving the catalytic activity of the alloy. The application aims to provide a formula and a preparation method for preparing a copper alloy cathode material capable of electrocatalytically reducing carbon dioxide to generate ethane at a low potential by adding Ga element to cooperate with Cu; and the specific technical scheme is as follows:

[0005] A copper-gallium alloy, wherein the mass percentage of gallium in the composition of the copper-gallium alloy is 3% to 10%.

[0006] Further, the mass percentage of gallium in the copper-gallium alloy component is 4.7% to 5.2%.

[0007] The application further discloses a preparation method of a cathode electrode material.

[0008] (1) batching: taking copper particles with a purity of 99.99 wt.% and liquid gallium with a purity of 99.99 wt.% as raw materials, the mass percentage of the liquid gallium in the batching is 3% to 10%, and the balance is the copper particles;

[0009] (2) smelting: placing the copper particles and the liquid gallium in an electric arc smelting furnace crucible tank, vacuumizing first, then introducing argon protection, repeatedly smelting for multiple times, and cooling to form an ingot;

[0010] (3) oxidation heat treatment: placing the ingot into a vacuum tube furnace, introducing argon first, then introducing dry air to perform heat oxidation treatment, and the oxidation heat treatment temperature is 120℃~500℃;

[0011] (4) rapid electric reduction: placing the cooled ingot into a three-electrode H-type electrolytic cell, the working electrode is the ingot treated in the step (3), the counter electrode is a platinum electrode, the reference electrode is saturated Ag / AgCl, the exchange membrane is an anion membrane, the electrolyte is a 0.5M KHCO3 solution, the reduction electrode is-0.8~-1.3V vs. Ag / AgCl voltage, and the reduction reaction is ended after the curve tends to be flat; and the cathode electrode material is generated.

[0012] The application further discloses a cathode electrode, and the material of the cathode electrode is prepared from the copper-gallium alloy and by the preparation method of the cathode electrode material.

[0013] The application further discloses a method for preparing double-carbon alkanes by electrically reducing carbon dioxide, which comprises the following steps:

[0014] (1) placing the cathode electrode into a container containing 0.5M KHCO3;

[0015] (2) the constant voltage potential is between-0.45 V vs. RHE and-0.65 V vs. RHE;

[0016] (3) continuously introducing carbon dioxide near the side of the cathode electrode; and performing an electrically catalytic reduction reaction of carbon dioxide.

[0017] In the application, the addition of Ga elements enables the copper alloy sheet to prepare ethane by electrically catalytic reduction of carbon dioxide at a low potential, which also provides a new technical route for subsequent realization of industrialization of the electrically catalytic reduction of carbon dioxide. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 The morphology change of Cu-Ga alloy in the process of annealing oxidation-quick electro-reduction; the annealing oxidation temperature is 500℃;

[0019] Figure 2 The schematic diagram of ethane generation efficiency in the process of electro-catalysis after the Cu-Ga alloy sheet is annealed and oxidized at 120-500℃ and then electro-reduced;

[0020] Figure 3 The XPS spectrum of surface element composition of Cu-Ga alloy in the process of annealing oxidation-quick electro-reduction; (a) Cu (b) Ga (c) O, the change from bottom to top corresponds to steps (2), (3) and (4) in Example 5, respectively;

[0021] Figure 4 The morphology change of Cu-Ga alloy in the process of annealing oxidation-quick electro-reduction; (a) Example 1: step (4) 120℃; (b) Example 2: step (4) 200℃; (c) Example 3: step (4) 300℃; (d) Example 4: step (4) 400℃. DETAILED DESCRIPTION

[0022] The application will be described in more detail below with examples. The application can be embodied in various different forms and should not be understood as being limited to the exemplary examples described herein. Example 1

[0023] A preparation method of a Ga-containing copper alloy cathode material is provided, and the percentage content of each component of the alloy is Ga: 4.7%; the balance is Cu and inevitable impurities.

[0024] The preparation steps of the copper alloy cathode material are as follows:

[0025] (1) batching: taking copper particles with a purity of 99.99 wt.% and liquid gallium with a purity of 99.99 wt.% as raw materials. The total mass of a single sample is 30g, and the above Ga and Cu are weighed according to the mass percentage.

[0026] (2) Melting-cutting-ultrasonic cleaning: pure Cu particles and pure Ga liquid metal were placed in the arc melting furnace crucible tank, and vacuumized for 40 min, at which time the gas pressure in the arc furnace was 3.2 Pa, and then argon was introduced to make the gas pressure in the furnace reach 0.05 MPa. The arc current was adjusted to 120 A, and after repeated melting for 3 times by using the arc, a Cu-Ga alloy ingot with uniform composition was obtained. The Cu-Ga alloy sheet was cut into a size of 10 mm x 10 mm x 0.5 mm by a wire cutting instrument, and finally sequentially cleaned by ultrasonic cleaning in acetone, alcohol, dilute hydrochloric acid and deionized water for 10 min, to obtain a clean and neat Cu-Ga alloy sheet.

[0027] (3) Oxidation heat treatment: the Cu-Ga alloy sheet obtained by melting, cutting and cleaning was subjected to oxidation heat treatment in a vacuum tube furnace. Before heating, 30 min of argon was introduced to remove impurity gases in the furnace tube, and the argon flow rate was 800 mL / min; then dry air was introduced until the end of the heat preservation, and the dry air flow rate was 600 mL / min; then the tube furnace program was set, the heat treatment temperature was 120°C, the heat preservation time was 2 h, and the Cu-Ga alloy sheet was cooled with the furnace.

[0028] (4) Rapid electro-reduction: the alloy sheet obtained by heat treatment in step (3) was reduced in a three-electrode H-type electrolytic cell built, the working electrode was the alloy sheet obtained in step (3), the counter electrode was a platinum electrode, the reference electrode was a saturated Ag / AgCl, the exchange membrane was an anion membrane, the electrolyte was a 0.5 M KHCO3 solution, a constant voltage CA curve was set, the reduction electrode was -0.8 V vs. Ag / AgCl voltage, and the reduction reaction ended after the curve tended to be flat. At this time, a rough surface was obtained as shown in Figure 4 (a).

[0029] (5) Electro-catalytic reduction of carbon dioxide; the Cu-Ga alloy sheet obtained in step (4) was subjected to electro-catalytic reduction of carbon dioxide under a constant voltage system, CO2 was introduced into the solution at the working electrode end for 30 min until the solution pH value reached 7.5. Then, under the condition of constant potential at -0.45 V vs. RHE, the reaction time was 1 h.

[0030] (6) After the Cu-Ga alloy obtained finally was subjected to electrochemical reaction, the gas phase products were calculated to be CH4, C2H6 and H2 by using Agilent 7890B / 5977B gas chromatograph, and the liquid phase products were HCOOH by using a 600 MHz liquid nuclear magnetic resonance instrument. Example 2

[0031] A method for preparing a Ga-containing copper alloy cathode material is provided, and the percentage content of each component of the alloy is Ga: 4.8%; the balance is Cu and unavoidable impurities.

[0032] The copper alloy cathode material preparation steps are as follows:

[0033] (1) batching: taking copper particles with a purity of 99.99 wt.% and liquid gallium with a purity of 99.99 wt.% as raw materials. The total mass of a single sample is 30 g, and the above Ga and Cu mass percentages are weighed.

[0034] (2) melting-cutting-ultrasonic cleaning: place pure Cu particles with a diameter of 3 mm and pure Ga liquid metal in the arc melting furnace crucible tank, and vacuumize for 45 min, at which time the gas pressure in the arc furnace is 3.2 Pa, then introduce argon to make the furnace gas pressure reach 0.05 MPa. Adjust the arc current to 130 A, and after repeated melting for 4 times, obtain a homogeneous Cu-Ga alloy ingot, cut the Cu-Ga alloy sheet into a size of 10 mm x 10 mm x 0.5 mm by a wire cutting instrument, and finally sequentially ultrasonic clean in acetone, alcohol, dilute hydrochloric acid and deionized water for 15 min, to obtain a clean and neat Cu-Ga alloy sheet.

[0035] (3) oxidation heat treatment: the Cu-Ga alloy sheet after melting, cutting and cleaning is subjected to oxidation heat treatment in a vacuum tube furnace. Before heating, introduce argon for 35 min to remove impurity gases in the furnace tube, and the argon flow rate is 700 mL / min; then introduce dry air until the end of the heat preservation, and the dry air flow rate is 650 mL / min; then set the tube furnace program, the heat treatment temperature is 200°C, the heat preservation time is 2h, and the Cu-Ga alloy sheet is cooled with the furnace.

[0036] (4) rapid electric reduction: the alloy sheet obtained by heat treatment in step (3) is reduced in a three-electrode H-type electrolytic cell built, the working electrode is the alloy sheet obtained in step (3), the counter electrode is a platinum electrode, the reference electrode is a saturated Ag / AgCl, the exchange membrane is an anion membrane, and the electrolyte is a 0.5M KHCO3 solution. The reduction electrode is -0.9V vs. Ag / AgCl voltage by setting constant voltage CA curve, and the reduction reaction ends after the curve tends to be flat. At this time, a rough surface with fine particles such as Figure 4 (b) is obtained, and the average particle size of the fine particles is 105 nm.

[0037] (5) electrocatalytic reduction of carbon dioxide; the Cu-Ga alloy sheet obtained in step (4) is subjected to electrocatalytic reduction of carbon dioxide under a constant voltage system, CO2 is introduced into the solution at the working electrode end for 30 min until the solution PH value reaches 7.4. Then under the condition of constant potential at -0.45V vs. RHE potential, the reaction time is 1h.

[0038] (6) The Cu-Ga alloy obtained finally is subjected to electrochemical reaction, and the gas-phase products are CH4, C2H6 and H2, which are measured by Agilent 7890B / 5977B gas chromatograph, and the liquid-phase products are HCOOH, which are measured by 600 MHz liquid-phase nuclear magnetic resonance instrument. Example 3

[0039] A Ga-containing copper alloy cathode material preparation method is provided, and the percentage content of each component of the alloy is Ga: 5%; the balance is Cu and unavoidable impurities.

[0040] The copper alloy cathode material preparation steps are as follows:

[0041] (1) Ingredients: pure copper particles with a purity of 99.99 wt.% and pure liquid gallium with a purity of 99.99 wt.% are used as raw materials. The total mass of a single sample is 30 g, and the above Ga and Cu mass percentages are weighed.

[0042] (2) Melting - cutting - ultrasonic cleaning: the pure Cu particles and the pure Ga liquid metal are placed in the arc melting furnace crucible tank, vacuumized for 50 min, at this time the gas pressure in the arc furnace is 3.1 Pa, then argon is introduced to make the gas pressure in the furnace reach 0.05 MPa. Adjust the arc current to 130 A, repeatedly melt 4 times by using the arc, then get the composition uniform Cu-Ga alloy ingot, cut the Cu-Ga alloy sheet into 10 mm x 10 mm x 0.5 mm in size by a wire cutting instrument, and finally sequentially clean the Cu-Ga alloy sheet by ultrasonic cleaning in acetone, alcohol, dilute hydrochloric acid and deionized water for 15 min, to obtain a clean and tidy Cu-Ga alloy sheet.

[0043] (3) Oxidation heat treatment: the Cu-Ga alloy sheet melted, cut and cleaned is subjected to oxidation heat treatment in a vacuum tube furnace. Before heating, 40 min of argon is introduced to remove impurity gases in the furnace tube, the argon flow rate is 900 mL / min; then dry air is introduced until the end of the heat preservation, the dry air flow rate is 700 mL / min; then the tube furnace program is set, the heat treatment temperature is 300℃, the heat preservation time is 2 h, and the Cu-Ga alloy sheet is cooled with the furnace.

[0044] (4) Rapid electro-reduction: the alloy sheet obtained by heat treatment in step (3) is subjected to reduction in a three-electrode H-type electrolytic cell built, the working electrode is the alloy sheet obtained in step (3), the counter electrode is a platinum electrode, the reference electrode is a saturated Ag / AgCl electrode, the exchange membrane is an anion membrane, and the electrolyte is a 0.5 M KHCO3 solution. The reduction electrode is -1.0 V vs. Ag / AgCl voltage by setting a constant voltage CA curve, and the reduction reaction ends after the curve tends to be flat. At this time, the surface obtains uneven nanoparticles like Figure 4 (c), and the average particle size of the nanoparticles is 180 nm.

[0045] (5) Electro-catalytic reduction of carbon dioxide; the Cu-Ga alloy sheet obtained in step (4) is subjected to electro-catalytic reduction of carbon dioxide under a constant voltage system, CO2 is introduced into the solution at the working electrode end for 30 min until the PH value of the solution reaches 7.3. Then, under the potential of -0.45 V vs. RHE, the reaction time is 1 h under the condition of constant potential.

[0046] (6) After the Cu-Ga alloy obtained finally is subjected to electrochemical reaction, the gas phase products are CH4, C2H6 and H2, which are calculated by using Agilent 7890B / 5977B gas chromatograph, and the liquid phase products are HCOOH, which are measured by using 600 MHz liquid nuclear magnetic resonance instrument. Example 4

[0047] A preparation method of a Ga-containing copper alloy cathode material is provided, and the percentage content of each component of the alloy is as follows: Ga: 5%; the balance is Cu and inevitable impurities.

[0048] The preparation steps of the copper alloy cathode material are as follows:

[0049] (1) Dosing: pure copper particles with a purity of 99.99 wt.% and pure liquid gallium with a purity of 99.99 wt.% are used as raw materials. The total mass of a single sample is 30 g, and the above Ga and Cu are weighed according to the mass percentage.

[0050] (2) Melting-cuting-ultrasonic cleaning: the pure Cu particles and the pure Ga liquid metal are placed in the arc melting furnace crucible tank, vacuumized for 50 min, at this time the gas pressure in the arc furnace is 3.1 Pa, then argon is introduced to make the gas pressure in the furnace reach 0.05 MPa. The arc current is adjusted to 140 A, the Cu-Ga alloy ingot with uniform composition is obtained after repeated arc melting for 5 times, the Cu-Ga alloy sheet is cut into a size of 10 mm x 10 mm x 0.5 mm by a wire cutting instrument, and finally sequentially ultrasonic cleaned in acetone, alcohol, dilute hydrochloric acid and deionized water for 15 min to obtain a Cu-Ga alloy sheet with clean and tidy surface.

[0051] (3) Oxidation heat treatment: the Cu-Ga alloy sheet after melting, cutting and cleaning is subjected to oxidation heat treatment in a vacuum tube furnace, 45 min of argon is introduced before heating to remove impurity gases in the furnace tube, the argon flow rate is 900 mL / min; then dry air is introduced until the end of heat preservation, the dry air flow rate is 750 mL / min; then the tube furnace program is set, the heat treatment temperature is 400℃, the heat preservation time is 2 h, and the Cu-Ga alloy sheet is cooled with the furnace.

[0052] (4) Fast electro-reduction: the alloy sheet obtained by the heat treatment of step (3) is reduced in a three-electrode H-type electrolytic cell, the working electrode is the alloy sheet obtained by step (3), the counter electrode is a platinum electrode, the reference electrode is a saturated Ag / AgCl electrode, the exchange membrane is an anion membrane, the electrolyte is a 0.5M KHCO3 solution, the reduction electrode is -1.1V vs. Ag / AgCl voltage by setting a constant voltage CA curve, and the reduction reaction is completed after the curve tends to be flat. At this time, the surface obtains uneven nanoparticles such as Figure 4 (d), and the average particle size of the nanoparticles is 225nm.

[0053] (5) Electro-catalytic reduction of carbon dioxide; the Cu-Ga alloy sheet obtained by step (4) is subjected to electro-catalytic reduction of carbon dioxide under a constant voltage system, CO2 is introduced into the solution at the working electrode end for 30min until the solution PH value reaches 7.3. Then under the condition of -0.45V vs. RHE potential, the reaction time is 1h under constant potential.

[0054] (6) After the final Cu-Ga alloy is subjected to electrochemical reaction, the gas phase products are CH4, C2H6 and H2 measured by Agilent 7890B / 5977B gas chromatograph, and the liquid phase products are HCOOH measured by a 600MHz liquid nuclear magnetic resonance instrument. Example 5

[0055] A Ga-containing copper alloy cathode material preparation method is provided, and the percentage content of each component of the alloy is Ga: 5%; the balance is Cu and unavoidable impurities.

[0056] The preparation steps of the copper alloy cathode material are as follows:

[0057] (1) batching: pure copper particles with a purity of 99.99 wt.% and pure liquid gallium with a purity of 99.99 wt.% are used as raw materials. The total mass of a single sample is 30g, and the above Ga and Cu are weighed according to the mass percentage.

[0058] (2) melting-cutting-ultrasonic cleaning: the pure Cu particles and the pure Ga liquid metal are placed in the arc melting furnace crucible slot, vacuumized for 40min, at this time the gas pressure in the arc furnace is 3.2 Pa, then argon gas is introduced to make the gas pressure in the furnace reach 0.05MPa. Adjust the arc current to 150A, repeatedly melt 5 times by arc, obtain a uniform Cu-Ga alloy ingot, cut the Cu-Ga alloy sheet into a size of 10mm×10mm×0.5mm by a wire cutting instrument, and finally sequentially ultrasonic clean in acetone, alcohol, dilute hydrochloric acid and deionized water for 10min, to obtain a clean and tidy Cu-Ga alloy sheet.

[0059] (3) Oxidation heat treatment: the Cu-Ga alloy sheet after smelting, cutting and cleaning is subjected to oxidation heat treatment in a vacuum tube furnace. Before heating, 50 min of argon is passed to remove impurity gas in the furnace tube, the argon flow rate is 1000 mL / min; dry air is then introduced until the end of the heat preservation, the dry air flow rate is 800 mL / min; and then the tube furnace program is set, the heat treatment temperature is 500°C, the heat preservation time is 2 h, and the Cu-Ga alloy sheet is cooled with the furnace.

[0060] (4) Fast electro-reduction: the alloy sheet obtained by the heat treatment in step (3) is subjected to reduction in a three-electrode H-type electrolytic cell. The working electrode is the alloy sheet obtained in step (3), the counter electrode is a platinum electrode, the reference electrode is a saturated Ag / AgCl, the exchange membrane is an anion membrane, the electrolyte is a 0.5M KHCO3 solution, the reduction electrode is -1.2V vs. Ag / AgCl voltage by setting a constant voltage CA curve, and the reduction reaction ends after the curve tends to be flat. At this time, uneven nanoparticles are obtained on the surface as shown in Figure 1 (c), and the average size of the nanoparticles is 900 nm.

[0061] (5) Electro-catalytic reduction of carbon dioxide: the Cu-Ga alloy sheet obtained in step (4) is subjected to electro-catalytic reduction of carbon dioxide under a constant voltage system. CO2 is introduced into the solution at the working electrode end for 30 min until the solution PH value reaches 7.3. Then, under the condition of -0.45 vs. RHE potential, the reaction time is 1 h under constant potential.

[0062] (6) After the electrochemical reaction of the finally obtained Cu-Ga alloy, the gas phase products are calculated to be CH4, C2H6 and H2 by using Agilent 7890B / 5977B gas chromatograph. The C2H6 faradic efficiency is 36% at -0.45V vs. RHE. Example 6

[0063] A method for preparing a Ga-containing copper alloy cathode material is provided. The percentage content of each component of the alloy is Ga: 5.1%; the balance is Cu and unavoidable impurities.

[0064] The preparation steps of the copper alloy cathode material are as follows:

[0065] (1) batching: copper particles with a purity of 99.99 wt.% and liquid gallium with a purity of 99.99 wt.% are used as raw materials. The total mass of a single sample is 30 g, and the above Ga and Cu are weighed according to the mass percentage.

[0066] (2) Melting-cutting-ultrasonic cleaning: pure Cu particles and pure Ga liquid metal were placed in the arc melting furnace crucible tank, and vacuumized for 60 min, at which time the gas pressure in the arc furnace was 3.0 Pa, and then argon was introduced to make the furnace gas pressure reach 0.05 MPa. The arc current was adjusted to 140 A, and after repeated melting for 4 times, a Cu-Ga alloy ingot with uniform composition was obtained. The Cu-Ga alloy sheet was cut into a size of 10 mm x 10 mm x 0.5 mm by a wire cutting instrument, and finally sequentially cleaned by ultrasonic cleaning in acetone, alcohol, dilute hydrochloric acid and deionized water for 20 min, to obtain a clean and neat Cu-Ga alloy sheet.

[0067] (3) Oxidation heat treatment: the Cu-Ga alloy sheet after melting, cutting and cleaning was subjected to oxidation heat treatment in a vacuum tube furnace. Before heating, 50 min of argon was introduced to remove impurity gases in the furnace tube, and the argon flow rate was 1000 mL / min; dry air was then introduced until the end of the heat preservation, and the dry air flow rate was 800 mL / min; and then the tube furnace program was set, the heat treatment temperature was 500°C, the heat preservation time was 2h, and the Cu-Ga alloy sheet was cooled with the furnace.

[0068] (4) Fast electro-reduction: the alloy sheet obtained by heat treatment in step (3) was reduced in a three-electrode H-type electrolytic cell, the working electrode was the alloy sheet obtained in step (3), the counter electrode was a platinum electrode, the reference electrode was a saturated Ag / AgCl, the exchange membrane was an anion membrane, and the electrolyte was a 0.5M KHCO3 solution. The reduction electrode was -1.3V vs. Ag / AgCl voltage using CA curve setting, and the reduction reaction ended after the curve tended to be flat. At this time, the surface obtained uneven nanoparticles with an average particle size of 850 nm.

[0069] (5) Electro-catalytic reduction of carbon dioxide; the Cu-Ga alloy sheet obtained in step (4) was subjected to electro-catalytic reduction of carbon dioxide under constant voltage system, CO2 was introduced into the solution at the working electrode end for 30 min until the solution PH value reached 7.3. Then under the condition of constant potential at -0.5 V vs. RHE potential, the reaction time was 1h.

[0070] (6) After the final Cu-Ga alloy was subjected to electrochemical reaction, the gas phase products were calculated to be: CH4, C2H6, H2 using Agilent 7890B / 5977B gas chromatograph, and the liquid phase products were measured to be: HCOOH using a 600MHz liquid nuclear magnetic resonance instrument. Example 7

[0071] A Ga-containing copper alloy cathode material preparation method is provided, and the percentage content of each component of the alloy is Ga: 5.2%; the balance is Cu and unavoidable impurities.

[0072] The copper alloy cathode material preparation steps are as follows:

[0073] (1) batching: taking copper particles with a purity of 99.99 wt.% and liquid gallium with a purity of 99.99 wt.% as raw materials. The total mass of a single sample is 30 g, and the above Ga and Cu mass percentages are weighed.

[0074] (2) melting - cutting - ultrasonic cleaning: place the pure Cu particles and the pure Ga liquid metal in the arc melting furnace crucible tank, and vacuumize for 60 min, at which time the gas pressure in the arc furnace is 3.0 Pa, then introduce argon to make the furnace gas pressure reach 0.05 MPa. Adjust the arc current to 140 A, and after 6 times of repeated melting, obtain a uniform Cu-Ga alloy ingot. Cut the Cu-Ga alloy sheet into a size of 10 mm x 10 mm x 0.5 mm by a wire cutting instrument, and finally sequentially clean it with acetone, alcohol, dilute hydrochloric acid and deionized water for 20 min to obtain a clean and neat Cu-Ga alloy sheet.

[0075] (3) oxidation heat treatment: the Cu-Ga alloy sheet after melting, cutting and cleaning is subjected to oxidation heat treatment in a vacuum tube furnace. Before heating, introduce argon for 50 min to remove impurity gases in the furnace tube, and the argon flow rate is 1000 mL / min; then introduce dry air until the end of the heat preservation, and the dry air flow rate is 800 mL / min; then set the tube furnace program, the heat treatment temperature is 500°C, the heat preservation time is 2h, and the Cu-Ga alloy sheet is cooled with the furnace.

[0076] (4) rapid electric reduction: the alloy sheet obtained by heat treatment in step (3) is subjected to reduction in a three-electrode H-type electrolytic cell built. The working electrode is the alloy sheet obtained in step (3), the counter electrode is a platinum electrode, the reference electrode is a saturated Ag / AgCl, the exchange membrane is an anion membrane, and the electrolyte is a 0.5M KHCO3 solution. The reduction electrode is -1.3V vs. Ag / AgCl voltage using a constant voltage CA curve, and the reduction reaction ends after the curve tends to be flat. At this time, the surface obtains uneven nanoparticles with an average particle size of 880 nm.

[0077] (5) electrocatalytic reduction of carbon dioxide; the Cu-Ga alloy sheet obtained in step (4) is subjected to electrocatalytic reduction of carbon dioxide under a constant voltage system, and CO2 is introduced into the solution at the working electrode end for 30 min until the solution PH value reaches 7.3. Then, under the condition of constant potential at -0.65V vs. RHE potential, the reaction time is 1h.

[0078] (6) The final Cu-Ga alloy after electrochemical reaction, using Agilent 7890B / 5977B gas chromatograph to calculate the gas phase products: CH4, C2H6, H2, using 600 MHz liquid nuclear magnetic resonance instrument to measure the liquid phase product: HCOOH.

[0079]

[0080] Table 1 Comparison of Faraday efficiency of products generated by examples

[0081] The above specific examples are further detailed descriptions of the present application, and cannot be considered as limiting the specific embodiments of the present application to only these. Without departing from the alloy composition range and the heat treatment-electro-reduction, electro-catalytic process proposed in the present application, appropriate component adjustment and improvement can be made, but all should be considered as belonging to the protection range of the claims submitted in the present application.

Claims

1. A copper-gallium alloy, characterized by, The mass percentage of gallium in the composition of the copper-gallium alloy is 3% to 10%, and the balance is copper and unavoidable impurities; the preparation method comprises the following steps: (1) batching: taking copper particles with a purity of 99.99 wt.% and liquid gallium with a purity of 99.99 wt.% as raw materials, the mass percentage of the liquid gallium in the batching is 3% to 10%, and the balance is pure copper particles; (2) smelting: placing the copper particles and the liquid gallium in an electric arc smelting furnace crucible tank, first vacuumizing, then introducing argon protection, repeatedly smelting by electric arc for multiple times, and cooling to form an ingot; (3) oxidation heat treatment: placing the ingot into a vacuum tube furnace, first introducing argon, then introducing dry air for heat oxidation treatment, and the oxidation heat treatment temperature is 120℃~500℃; (4) rapid electric reduction: placing the cooled ingot into a three-electrode H-type electrolytic cell, the working electrode is the ingot treated by step (3); the counter electrode is a platinum electrode, the reference electrode is saturated Ag / AgCl, the exchange membrane is an anion membrane, the electrolyte is a 0.5MKHCO3 solution, the reduction electrode is-0.8V~-1.3 V vs. Ag / AgCl voltage by setting a constant voltage CA curve, and the reduction reaction ends after the curve tends to a platform; the copper-gallium alloy is generated.

2. The copper-gallium alloy of claim 1, wherein, The mass percentage of gallium in the composition of the copper-gallium alloy is 4.7% to 5.2%.

3. A method for producing a cathode electrode material, characterized by, Comprising the following steps: (1) batching: taking copper particles with a purity of 99.99 wt.% and liquid gallium with a purity of 99.99 wt.% as raw materials, the mass percentage of the liquid gallium in the batching is 3% to 10%, and the balance is pure copper particles; (2) smelting: placing the copper particles and the liquid gallium in an electric arc smelting furnace crucible tank, first vacuumizing, then introducing argon protection, repeatedly smelting by electric arc for multiple times, and cooling to form an ingot; (3) oxidation heat treatment: placing the ingot into a vacuum tube furnace, first introducing argon, then introducing dry air for heat oxidation treatment, and the oxidation heat treatment temperature is 120℃~500℃; (4) rapid electric reduction: placing the cooled ingot into a three-electrode H-type electrolytic cell, the working electrode is the ingot treated by step (3); the counter electrode is a platinum electrode, the reference electrode is saturated Ag / AgCl, the exchange membrane is an anion membrane, the electrolyte is a 0.5MKHCO3 solution, the reduction electrode is-0.8V~-1.3 V vs. Ag / AgCl voltage by setting a constant voltage CA curve, and the reduction reaction ends after the curve tends to a platform; the cathode electrode material is generated.

4. A cathode electrode, characterized by The cathode electrode material adopts the copper-gallium alloy according to claim 1 or 2.

5. A method for the production of ethane by the electroreduction of carbon dioxide, characterized by: The cathode electrode adopts the cathode electrode according to claim 4, comprising the following steps: (1) placing the cathode electrode into a container containing 0.5M KHCO3; (2) the constant voltage potential is between-0.45 vs. RHE and-0.65 vs. RHE; (3) continuously introducing carbon dioxide near the cathode electrode side; and performing the electrocatalytic reduction of carbon dioxide reaction.

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