A nickel-based alloy catalyst, its preparation method and its application in the field of electrocatalysis
By preparing a nickel-based alloy catalyst, the problems of low efficiency and poor stability of catalysts for the electroreduction of carbon dioxide to ethylene were solved, realizing efficient and low-cost electrocatalytic production of ethylene from carbon dioxide, which has the potential for industrial application.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- WANHUA CHEM GRP CO LTD
- Filing Date
- 2025-01-02
- Publication Date
- 2026-07-03
AI Technical Summary
Existing catalysts for the electroreduction of carbon dioxide to ethylene suffer from low efficiency and poor stability, and catalysts doped with lanthanides are expensive, making industrial application difficult.
A nickel-based alloy catalyst, comprising nickel as the main metal and three or more of the alloy metals copper, cobalt, chromium, iron, manganese, tin, bismuth, and zinc, is loaded onto a carbon-based support and prepared through oxidation and heat treatment to produce a uniformly distributed nanoscale high-entropy alloy catalyst for the electrocatalytic production of ethylene from carbon dioxide.
This method achieves highly active and long-life electrocatalytic production of ethylene from carbon dioxide, improves the kinetic efficiency and stability of CO2RR and ORR reactions, avoids the use of precious metals, and has the potential for large-scale production.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of electrochemistry, specifically relating to a nickel-based alloy catalyst, its preparation method, and its application in the electrocatalytic production of ethylene from carbon dioxide. Background Technology
[0002] With the increasing severity of global climate change and the energy crisis, the reduction and reuse of carbon dioxide emissions has become a research hotspot. Among these, carbon dioxide electroreduction technology has attracted much attention due to its ability to convert carbon dioxide into valuable chemicals. However, the catalyst efficiency and stability of this technology still face significant challenges, making the development of novel and highly efficient catalysts crucial.
[0003] Patent CN 1 18272859A discloses a catalyst for the electrocatalytic reduction of carbon dioxide to produce ethylene and its preparation method. It uses doped lanthanide elements as catalysts, but due to the high doping amount and high cost, it cannot be used in industrial applications.
[0004] Ethylene is one of the most basic raw materials in the petrochemical industry. It is a fundamental chemical feedstock for synthetic fibers, synthetic rubber, synthetic plastics (polyethylene (PE), high-density polyethylene (HDPE), polyvinyl chloride (PVC), and synthetic ethanol (alcohol), among others. Industrially, it is produced through the steam cracking of ethane and naphtha. However, the steam cracking method for producing ethylene has drawbacks such as high energy consumption and high carbon emissions. In contrast, the method of reducing carbon dioxide to ethylene through an electrochemical reaction offers advantages such as being environmentally friendly and producing high purity, and has been a key focus of research in the industry. Summary of the Invention
[0005] To overcome the shortcomings of existing technologies, this invention provides a nickel-based alloy catalyst and its preparation method. Compared with other catalysts, it has a longer service life and exhibits good activity and CO2 conversion rate during electrolysis.
[0006] The present invention also provides the application of the catalyst in the electrocatalytic production of ethylene from carbon dioxide.
[0007] To achieve the objectives of this invention, the following technical solution is provided:
[0008] A nickel-based alloy catalyst includes a support and a metal active component, wherein the metal active component includes three or more of the following: main metal nickel and alloy metals: copper, cobalt, chromium, iron, manganese, tin, aluminum, bismuth, and zinc. Preferably, the alloy metal is copper, manganese, cobalt, and iron, wherein the mass ratio of copper, manganese, cobalt, and iron is 2:1 to 1.5:1 to 3:1 to 3.
[0009] The carrier is a carbon-based carrier, preferably carbon black, including but not limited to conductive carbon black (CcB), acetylene black (AcB), rubber carbon black, pyrolysis carbon black, and special carbon black.
[0010] Preferably, the metal loading is 3-30 wt% of the catalyst mass, more preferably 5-20 wt%.
[0011] Preferably, the mass ratio of the nickel metal to the alloy metal is 1:(1-5), more preferably 1:1.5-2.5.
[0012] This invention also provides a method for preparing a nickel-based alloy catalyst, comprising the following steps:
[0013] (1) Add the carrier to the oxidant solution and mix evenly to oxidize the carrier. Then separate and dry to obtain the modified carrier.
[0014] (2) Mix the nickel salt and alloy metal salt solution, add the modified carrier, stir and mix evenly, load the nickel metal and alloy metal onto the modified carrier, separate and dry to obtain the nickel-based alloy support carrier.
[0015] Preferably, the oxidant is one or more selected from hydrogen peroxide, sodium hypochlorite, potassium hypochlorite, potassium dichromate, potassium permanganate, and sodium persulfate, and the concentration of the oxidant is preferably 0.5-1 mol / L.
[0016] (3) In an N2 atmosphere, the precursor powder is heat-treated, cooled, cleaned and dried to obtain carbon black-loaded nickel-based alloy material.
[0017] Preferably, the mass ratio of the carrier to the oxidant solution is 0.05-0.05:1;
[0018] In step (1), the modified carrier can be obtained by centrifugation at a speed of 2000-10000 rpm / min for 5-20 min. Preferably, in step (1), the carrier is soaked in the oxidant for 6-24 h. After centrifugation, the carrier is washed by alternating washing with water and ethanol.
[0019] The mixing speed in step (1) is 200-1000 rpm / min, and the mixing time is 6-24 h. Preferably, the drying temperature in step (1) is 50-70℃, and the drying time is 2-8 h.
[0020] In step (2), the nickel salt is nickel chloride, nickel nitrate, nickel sulfate, or nickel carbonate.
[0021] Copper salts include copper chloride, copper sulfate, copper nitrate, basic copper sulfate, or basic copper carbonate.
[0022] The cobalt salts are cobalt chloride, cobalt hydroxide, cobalt sulfate, cobalt carbonate, or cobalt neodecanoate.
[0023] The chromium salt is chromium chloride, potassium chromate, chromic anhydride, or potassium dichromate.
[0024] The iron salts are ferric chloride, ferric sulfate, or ferric nitrate.
[0025] Manganese salts include manganese chloride, manganese sulfate, manganese carbonate, or manganese stearate.
[0026] Tin salts are tin tetrachloride, tin nitrate, tin methanesulfonate, or tin sulfate.
[0027] Aluminum salts include aluminum chloride, aluminum sulfate, alum, or aluminum nitrate.
[0028] The bismuth salts are bismuth trichloride, bismuth isooctanoate, bismuth laurate, and bismuth neodecanoate.
[0029] The zinc salts are zinc chloride, zinc sulfate, zinc nitrate, zinc fluorosilicate, zinc fluoroborate, or zinc acetate.
[0030] In step (2), the nickel salt or alloy metal salt is dissolved in a polar solvent, which is one or more of ethanol, ethylene glycol, isopropanol, chloroform, and hexane.
[0031] In step (2), the stirring speed is 200-1000 rpm / min and the stirring time is 6-24h; preferably, step (2) is performed under ultrasonic conditions, with an ultrasonic power of 30-100W and an ultrasonic time of 0.5-2h.
[0032] In step (2), the nickel-based alloy support can be separated by rotary evaporation at a temperature of 50-70°C.
[0033] In step (2), the drying temperature is 50-70℃ and the drying time is 6-12h.
[0034] The heat treatment temperature in step (3) is 650-850℃, the treatment time is 5-20s, and the cooling method is natural cooling in N2 atmosphere.
[0035] In step (3), water and ethanol can be used for alternating washing, the drying temperature is 50-70℃, and the drying time is 6-12h.
[0036] The present invention also provides the application of the nickel-based alloy catalyst in the electrocatalytic production of ethylene from carbon dioxide.
[0037] This invention provides a method for preparing ethylene by reducing CO2 to C2H4 via electrocatalysis.
[0038] In this invention, the cathode electrode in the electrocatalytic reaction is loaded with the nickel-based alloy catalyst described in this invention.
[0039] In this invention, the anode is a nickel electrode, preferably a nickel foam electrode.
[0040] In this invention, the electrocatalysis is preferably carried out in a gas diffusion electrode flow cell;
[0041] In this invention, the electrolyte in the electrocatalytic process is an aqueous KOH solution, preferably a 1-3 mol / L aqueous KOH solution;
[0042] Preferably, the cathode electrolyte and the anolyte are the same.
[0043] Preferably, the cathode and anode are separated by a cation exchange membrane.
[0044] In this invention, the CO2 gas flow rate in the electrocatalytic process is 10-30 sccm, preferably 10 sccm;
[0045] In this invention, the current density is 100-500 mA / cm². 2 300mA / cm is preferred 2 The electrolysis reaction temperature is room temperature.
[0046] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0047] (1) Compared with common methods for preparing nano-high entropy alloy materials, such as electrodeposition, this invention can stably, greenly, and cost-effectively synthesize nano-high entropy alloy catalysts on a large scale, avoiding the use of precious metals. The prepared high entropy alloy particles are uniform and uniformly loaded on single-point carbon black carbon materials, exhibiting excellent activity in the electrocatalytic production of ethylene from carbon dioxide, improving the kinetic efficiency and stability of CO2RR, CORR and ORR reactions, and achieving high activity and low cost.
[0048] (2) In terms of preparation method, the present invention has the advantages of simple preparation process, low equipment requirements and large-scale synthesis; in terms of catalyst morphology, the prepared FeCoCuMnNi-CcB has a very small alloy particle diameter, which is only 10nm as measured, and is very uniformly distributed on the surface of conductive carbon black.
[0049] (3) In terms of catalytic activity and stability, FeCoCuMnNi-CcB exhibits excellent electrocatalytic performance in alkaline media, with high Faradaic efficiency in the electrocatalytic production of ethylene from carbon dioxide and a current density of 300 mA / cm². 2 This catalyst has been operating stably for over 130 hours under certain conditions, and it is expected to enable large-scale application of carbon dioxide electrocatalytic production of ethylene. Attached Figure Description
[0050] Figure 1These are the LSV curves of the electrocatalytic production of ethylene from carbon dioxide in Examples 1-6 and Comparative Examples 1 and 2.
[0051] Figure 2 This is a graph showing the Faraday efficiency versus operating time in the electrocatalytic reduction of carbon dioxide to ethylene applications of Examples 1-6 and Comparative Examples 1 and 2. Detailed Implementation
[0052] To better understand the process of this invention, further explanation will be provided below in conjunction with embodiments.
[0053] Unless otherwise specified, all raw materials and equipment used in this invention are commercially available or commonly used in the field.
[0054] Unless otherwise specified, the methods described in the embodiments are conventional methods in the art.
[0055] Example 1
[0056] A nickel-based alloy catalyst, FeCoCuMnNi-CcB, is prepared using the following method:
[0057] Step 1: Add 285 mg of conductive carbon black (CcB) to 14.25 g of 0.5 M hydrogen peroxide aqueous solution, soak and stir at 1000 rpm / min for more than 6 hours, wash three times with deionized water and ethanol alternately, centrifuge at 3000 rpm / min for 15 minutes, and dry in an oven at 60℃ for more than 4 hours to obtain conductive carbon black (CcB) carrier.
[0058] Step 2: Add 40 mg ferric sulfate, 18.6 mg cobalt hydroxide, 32 mg copper sulfate, 39 mg nickel chloride, and 12.6 mg manganese chloride to an ethanol solution, then add 285 mg conductive carbon black (CcB) carrier. Stir at 1000 rpm / min for more than 6 hours, use an ultrasonic power of 50 W for 45 minutes, rotary evaporation at 60℃, and vacuum oven drying at 60℃ for 6 hours to obtain high-entropy alloy precursor powder.
[0059] Step 3: In a tube furnace under N2 atmosphere, the precursor powder was rapidly heat-treated at 800℃ for 10 seconds using an electrically triggered Joule heating device. After cooling to room temperature, it was washed three times alternately with deionized water and ethanol. The powder was then dried in a vacuum oven at 60℃ for 6 hours to obtain carbon black-supported nickel-based nano-high-entropy alloy material (FeCoCuMnNi-CcB). The mass ratio of each metal was approximately 1:2:2:1:4.
[0060] The prepared nanocatalyst FeCoCuMn-CcB (10 mg) and 5 μL of a 5% Nafion 117 perfluorinated resin ionomer solution (Merck, water as solvent) were uniformly dispersed in 5 mL of isopropanol (Beijing Inokai Technology Co., Ltd., purity ≥99.5%). The dispersion was then uniformly sprayed onto carbon paper (Toray carbon paper, TGP-H-6) using a spray gun and dried at room temperature for 4 h to obtain a black gas diffusion electrode (reaction area 1 cm²). 2 The samples were collected and stored in a desiccator filled with argon gas for later use.
[0061] The electrocatalytic reduction of CO2 to prepare C2H4: The nickel-based alloy electrode obtained above was used as the cathode, nickel foam as the anode, 3 mol / L KOH solution as the electrolyte, and a perfluorosulfonic acid resin cation exchange membrane (Dongyue, DM8115A) was used as the separator. The electrolyte was prepared in a gas diffusion electrolysis cell (Gaoshi Ruilian, model 101012-1) at 300 mA / cm². 2 The current density was reduced; the electrolyte flow rate was 15 ml / min; and the carbon dioxide flow rate was 10 sccm / min.
[0062] Electrochemical workstation measurements: The current was controlled using an electrochemical workstation (Metroën Autolab PGSTAT101), with a silver / silver chloride electrode as the reference electrode. Cyclic CV tests were performed at a scan rate of 10 mV / s, typically for 15 cycles until the CV curve stabilized. Then, the LSV polarization curve was measured. The scan rate for the LSV polarization curve was generally chosen to be 10 mV / s, and the potential was typically -0.7 to -0.1 V vs Ag / AgCl. IR compensation was set to 85%. The stability of the working electrode also needed to be tested, here using the chronoamperometry method. The results are as follows... Figure 1 As shown.
[0063] Gas phase products were analyzed using gas chromatography (Shimadzu Corporation, model GC2030), and liquid phase products were analyzed using liquid chromatography (Agilent, model 1260Ⅱ).
[0064] The Faraday efficiency versus running time of the electrode in this embodiment in the electrocatalytic reduction of carbon dioxide to ethylene is shown in the figure. Figure 2 The gas diffusion electrode of the nickel-based alloy catalyst prepared in Example 1 of this invention can achieve highly selective electrocatalytic reduction of CO2 to C2H4 at high current density under normal temperature and pressure, and the Faraday efficiency of the product C2H4 reaches up to 86.4%. After 134 hours of stable operation, the catalyst efficiency did not decrease.
[0065] Example 2
[0066] The specific preparation method of the high-entropy alloy CoCuMnNi-CcB for the electrocatalytic production of ethylene from carbon dioxide is as follows:
[0067] Step 1: Add 285 mg of conductive carbon black (CcB) to 14.25 g of 0.5 M hydrogen peroxide aqueous solution, soak and stir at 1000 rpm / min for more than 6 hours, wash three times with deionized water and ethanol alternately, centrifuge at 3000 rpm / min for 15 min, and dry in an oven at 60℃ for more than 4 hours to obtain conductive carbon black (CcB) carrier.
[0068] Step 2: Add 30 mg of nickel chloride, 18.6 mg of cobalt hydroxide, 32 mg of copper sulfate, and 12.6 mg of manganese chloride to an ethanol solution, then add 285 mg of conductive carbon black (CcB) carrier. Stir at 1000 rpm / min for more than 6 hours, use an ultrasonic power of 50 W for 45 minutes, a rotary evaporation temperature of 60℃, and a vacuum oven drying temperature of 60℃ for 6 hours to obtain high-entropy alloy precursor powder.
[0069] Step 3: In a tube furnace under N2 atmosphere, the precursor powder is rapidly heat-treated at 800℃ for 10 seconds using an electrically triggered Joule heating device. After cooling to room temperature, it is washed three times alternately with deionized water and ethanol. The powder is then dried in a vacuum oven at 60℃ for 6 hours to obtain a carbon black-supported nickel-based alloy material (FeCoCuMn-CcB). The mass ratio of each metal is Co:Cu:Mn:Ni = 1:3:3:3.
[0070] The nickel-based alloy electrode was prepared using the same method as in Example 1, except that the nickel-based alloy catalyst prepared in Example 2 was used instead of the nickel-based alloy catalyst prepared in Example 1.
[0071] The same method as in Example 1 was used to prepare C2H4 by electrocatalytic reduction of CO2. The main difference was that the electrode prepared in this example was used as the cathode and the carbon dioxide flow rate was 20 sccm / min.
[0072] The performance was tested using the same method as in Example 1, and the Faraday efficiency of the generated product C2H4 reached a maximum of 77.1%.
[0073] Example 3
[0074] The specific preparation method of the high-entropy alloy CoCuMnNi-CcB for the electrocatalytic production of ethylene from carbon dioxide is as follows:
[0075] Step 1: Add 285 mg of conductive carbon black (CcB) to 14.25 g of 0.5 M hydrogen peroxide aqueous solution, soak and stir at 1000 rpm / min for more than 6 hours, wash three times with deionized water and ethanol alternately, centrifuge at 3000 rpm / min for 15 min, and dry in an oven at 60℃ for more than 4 hours to obtain conductive carbon black (CcB) carrier.
[0076] Step 2: Add 18.6 mg cobalt hydroxide, 32 mg copper sulfate, 39 mg nickel chloride, and 12.6 mg manganese chloride to an ethanol solution, then add 285 mg conductive carbon black (CcB) carrier. Stir at 1000 rpm / min for more than 6 hours, use an ultrasonic power of 50 W for 45 minutes, rotary evaporation at 60℃, and vacuum oven drying at 60℃ for 6 hours to obtain high-entropy alloy precursor powder.
[0077] Step 3: In a tube furnace under N2 atmosphere, the precursor powder was rapidly heat-treated at 800℃ for 10 seconds using an electrically triggered Joule heating device. After cooling to room temperature, it was washed three times alternately with deionized water and ethanol. The powder was then dried in a vacuum oven at 60℃ for 6 hours to obtain a carbon black-supported nickel-based nano-high-entropy alloy material (CoCuMnNi-CcB). The mass ratio of each metal was Mn:Co:Cu:Ni = 1:2:3:4.
[0078] The nickel-based alloy electrode was prepared using the same method as in Example 1, except that the nickel-based alloy catalyst prepared in Example 3 was used instead of the nickel-based alloy catalyst prepared in Example 1.
[0079] The same method as in Example 1 was used to prepare C2H4 by electrocatalytic reduction of CO2. The main difference was that the electrode prepared in this example was used as the cathode and the carbon dioxide flow rate was 20 sccm / min.
[0080] The performance was tested using the same method as in Example 1, and the Faraday efficiency of the generated product C2H4 reached up to 70.2%.
[0081] Example 4
[0082] The specific preparation method of the high-entropy alloy FeCuMnNi-CcB for the electrocatalytic production of ethylene from carbon dioxide is as follows:
[0083] Step 1: Add 285 mg of conductive carbon black (CcB) to 14.25 g of 0.5 M hydrogen peroxide aqueous solution, soak and stir at 1000 rpm / min for more than 6 hours, wash three times with deionized water and ethanol alternately, centrifuge at 3000 rpm / min for 15 min, and dry in an oven at 60℃ for more than 4 hours to obtain conductive carbon black (CcB) carrier.
[0084] Step 2: Add 40mg ferric sulfate, 32mg copper sulfate, 39mg nickel chloride, and 12.6mg manganese chloride to an ethanol solution, then add 285mg conductive carbon black (CcB) carrier. Stir at 1000rpm / min for more than 6 hours, use an ultrasonic power of 50W for 45 minutes, rotary evaporation at 60℃, and vacuum oven drying at 60℃ for 6 hours to obtain high-entropy alloy precursor powder.
[0085] Step 3: In a tube furnace under N2 atmosphere, the precursor powder was rapidly heat-treated at 800℃ for 10 seconds using an electrically triggered Joule heating device. After cooling to room temperature, it was washed three times alternately with deionized water and ethanol. The powder was then dried in a vacuum oven at 60℃ for 6 hours to obtain carbon black-supported nickel-based nano-high-entropy alloy material (FeCuMnNi-CcB). The mass ratio of each metal was Fe:Cu:Mn:Ni = 1:3:2:4.
[0086] The nickel-based alloy electrode was prepared using the same method as in Example 1, except that the nickel-based alloy catalyst prepared in Example 4 was used instead of the nickel-based alloy catalyst prepared in Example 1.
[0087] The same method as in Example 1 was used to prepare C2H4 by electrocatalytic reduction of CO2. The main difference was that the electrode prepared in this example was used as the cathode and the carbon dioxide flow rate was 20 sccm / min.
[0088] The performance was tested using the same method as in Example 1, and the Faraday efficiency of the generated product C2H4 reached up to 70.4%.
[0089] Example 5
[0090] The specific preparation method of the high-entropy alloy FeCoMnNi-CcB for the electrocatalytic production of ethylene from carbon dioxide is as follows:
[0091] Step 1: Add 285 mg of conductive carbon black (CcB) to 14.25 g of 0.5 M hydrogen peroxide aqueous solution, soak and stir at 1000 rpm / min for more than 6 hours, wash three times with deionized water and ethanol alternately, centrifuge at 3000 rpm / min for 15 min, and dry in an oven at 60℃ for more than 4 hours to obtain conductive carbon black (CcB) carrier.
[0092] Step 2: Add 40 mg of ferric sulfate, 18.6 mg of cobalt hydroxide, 39 mg of nickel chloride, and 12.6 mg of manganese chloride to an ethanol solution, then add 285 mg of conductive carbon black (CcB) carrier. Stir at 1000 rpm / min for more than 6 hours, use an ultrasonic power of 50 W for 45 minutes, rotary evaporation at 60℃, and vacuum oven drying at 60℃ for 6 hours to obtain high-entropy alloy precursor powder.
[0093] Step 3: In a tube furnace under N2 atmosphere, the precursor powder was rapidly heat-treated at 800℃ for 10 seconds using an electrically triggered Joule heating device. After cooling to room temperature, it was washed three times alternately with deionized water and ethanol, and then dried in a vacuum oven at 60℃ for 6 hours to obtain carbon black-supported nickel-based nano-high-entropy alloy material (FeCoMnNi-CcB). The mass ratio of each metal was Fe:Co:Mn:Ni = 1:3:3:5.
[0094] The nickel-based alloy electrode was prepared using the same method as in Example 1, except that the nickel-based alloy catalyst prepared in Example 5 was used instead of the nickel-based alloy catalyst prepared in Example 1.
[0095] C2H4 was prepared by CO2 electrocatalytic reduction using the same method as in Example 1. The main difference is that the electrode prepared in this example was used as the cathode, and the carbon dioxide flow rate was 30 sccm / min.
[0096] The performance was tested using the same method as in Example 1, and the Faraday efficiency of the generated product C2H4 reached up to 69.5%.
[0097] Example 6
[0098] The specific preparation method of the high-entropy alloy FeCoCuNi-CcB for the electrocatalytic production of ethylene from carbon dioxide is as follows:
[0099] Step 1: Add 285 mg of conductive carbon black (CcB) to 14.25 g of 0.5 M hydrogen peroxide aqueous solution, soak and stir at 1000 rpm / min for more than 6 hours, wash three times with deionized water and ethanol alternately, centrifuge at 3000 rpm / min for 15 min, and dry in an oven at 60℃ for more than 4 hours to obtain conductive carbon black (CcB) carrier.
[0100] Step 2: Add 40 mg of ferric sulfate, 18.6 mg of cobalt hydroxide, 32 mg of copper sulfate, and 39 mg of nickel chloride to an ethanol solution, then add 285 mg of conductive carbon black (CcB) carrier. Stir at 1000 rpm / min for more than 6 hours, use an ultrasonic power of 50 W for 45 minutes, rotary evaporation at 60℃, and vacuum oven drying at 60℃ for 6 hours to obtain high-entropy alloy precursor powder.
[0101] Step 3: In a tube furnace under N2 atmosphere, the precursor powder was rapidly heat-treated at 800℃ for 10 seconds using an electrically triggered Joule heating device. After cooling to room temperature, it was washed three times alternately with deionized water and ethanol. The powder was then dried in a vacuum oven at 60℃ for 6 hours to obtain carbon black-supported nickel-based nano-high-entropy alloy material (FeCoCuNi-CcB). The mass ratio of each metal was Fe:Co:Cu:Ni = 1:2:3:4.
[0102] The nickel-based alloy electrode was prepared using the same method as in Example 1, except that the nickel-based alloy catalyst prepared in Example 6 was used instead of the nickel-based alloy catalyst prepared in Example 1.
[0103] The same method as in Example 1 was used to prepare C2H4 by electrocatalytic reduction of CO2. The main difference was that the electrode prepared in this example was used as the cathode and the carbon dioxide flow rate was 20 sccm / min.
[0104] The performance was tested using the same method as in Example 1, and the Faraday efficiency of the generated product C2H4 reached up to 70.3%.
[0105] Comparative Example 1
[0106] The specific preparation method of the high-entropy alloy FeNi-CcB for the electrocatalytic production of ethylene from carbon dioxide is as follows:
[0107] Step 1: Add 285 mg of conductive carbon black (CcB) to 14.25 g of 0.5 M hydrogen peroxide aqueous solution, soak and stir at 1000 rpm / min for more than 6 hours, wash three times with deionized water and ethanol alternately, centrifuge at 3000 rpm / min for 15 min, and dry in an oven at 60℃ for more than 4 hours to obtain conductive carbon black (CcB) carrier.
[0108] Step 2: Add 40 mg of ferric sulfate and 39 mg of nickel chloride to an ethanol solution, then add 285 mg of conductive carbon black (CcB) carrier, stir at 1000 rpm / min for more than 6 hours, use an ultrasonic power of 50 W for 45 minutes, use a rotary evaporation temperature of 60℃, and use a vacuum oven drying temperature of 60℃ for 6 hours to obtain high-entropy alloy precursor powder.
[0109] Step 3: In a tube furnace under N2 atmosphere, the precursor powder was rapidly heat-treated at 800℃ for 10 seconds using an electrically triggered Joule heating device. After cooling to room temperature, it was washed three times alternately with deionized water and ethanol. The powder was then dried in a vacuum oven at 60℃ for 6 hours to obtain carbon black-supported nickel-based nano-high-entropy alloy material (FeNi-CcB). The mass ratio of each metal was Fe:Ni = 8:2.
[0110] The nickel-based alloy electrode was prepared using the same method as in Example 1, except that the nickel-based alloy catalyst prepared in Comparative Example 1 was used instead of the nickel-based alloy catalyst prepared in Example 1.
[0111] C2H4 was prepared by CO2 electrocatalytic reduction using the same method as in Example 1. The main difference was that the electrode prepared in this comparative example was used as the cathode, and the carbon dioxide flow rate was 20 sccm / min.
[0112] The performance was tested using the same method as in Example 1, and the Faraday efficiency of the generated product C2H4 reached up to 46%.
[0113] Comparative Example 2
[0114] The specific preparation method of the high-entropy alloy FeCoNi-CcB for the electrocatalytic production of ethylene from carbon dioxide is as follows:
[0115] Step 1: Add 285 mg of conductive carbon black (CcB) to 14.25 g of 0.5 M hydrogen peroxide aqueous solution, soak and stir at 1000 rpm / min for more than 6 hours, wash three times with deionized water and ethanol alternately, centrifuge at 3000 rpm / min for 15 min, and dry in an oven at 60℃ for more than 4 hours to obtain conductive carbon black (CcB) carrier.
[0116] Step 2: Add 40 mg of ferric sulfate, 18.6 mg of cobalt hydroxide, and 39 mg of nickel chloride to an ethanol solution, then add 285 mg of conductive carbon black (CcB) carrier. Stir at 1000 rpm / min for more than 6 hours, use an ultrasonic power of 50 W for 45 minutes, a rotary evaporation temperature of 60℃, and a vacuum oven drying temperature of 60℃ for 6 hours to obtain high-entropy alloy precursor powder.
[0117] Step 3: In a tube furnace under N2 atmosphere, the precursor powder was rapidly heat-treated at 800℃ for 10 seconds using an electrically triggered Joule heating device. After cooling to room temperature, it was washed three times alternately with deionized water and ethanol. The powder was then dried in a vacuum oven at 60℃ for 6 hours to obtain carbon black-supported nickel-based nano-high-entropy alloy material (FeCoNi-CcB). The mass ratio of each metal was Co:Fe:Ni = 4:1:5.
[0118] The nickel-based alloy electrode was prepared using the same method as in Example 1, except that the nickel-based alloy catalyst prepared in Comparative Example 2 was used instead of the nickel-based alloy catalyst prepared in Example 1.
[0119] C2H4 was prepared by CO2 electrocatalytic reduction using the same method as in Example 1. The main difference was that the electrode prepared in Comparative Example 2 was used as the cathode, and the carbon dioxide flow rate was 20 sccm / min.
[0120] The performance was tested using the same method as in Example 1, and the Faraday efficiency of the generated product C2H4 reached up to 69%.
[0121] Figure 1 The figures show the LSV curves of the nickel-based high-entropy alloys supported on different carbon blacks prepared in Examples 1-6 and the electrocatalytic production of ethylene from carbon dioxide in Comparative Examples 1 and 2. It can be seen from the figures that the electrolysis performance of the alloy of the present invention as a catalyst is better than that of the comparative examples.
[0122] The prepared FeCoCuMnNi-CcB exhibits high CO2RR electrocatalytic activity and excellent stability in alkaline media, and its performance at 300 mA / cm² is also remarkable. 2 The catalyst activity did not decrease after 134 hours of continuous operation (e.g.) Figure 2 As shown in the figure, this provides an excellent catalyst that can replace precious metals for the electrocatalytic production of ethylene from carbon dioxide in alkaline media.
[0123] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the present invention.
Claims
1. A nickel-based alloy catalyst, comprising a support and a metallic active component, characterized in that, The active metal component includes three or more of the main metal nickel and alloy metals copper, cobalt, chromium, iron, manganese, tin, aluminum, bismuth, and zinc. Preferably, the alloy metal is copper, manganese, cobalt, and iron, wherein the mass ratio of copper, manganese, cobalt, and iron is 2:1 to 1.5:1 to 3:1 to 3.
2. The catalyst according to claim 1, characterized in that, The carrier is a carbon-based carrier, preferably carbon black, including but not limited to conductive carbon black, acetylene black, rubber black, pyrolysis carbon black, and special carbon black; Preferably, the metal loading is 3-30 wt% of the catalyst mass, more preferably 5-20 wt%. Preferably, the mass ratio of the nickel metal to the alloy metal is 1:(1-5), more preferably 1:1.5-2.
5.
3. A method for preparing the catalyst according to claim 1 or 2, characterized in that, Includes the following steps: (1) Add the carrier to the oxidant solution and mix evenly to oxidize the carrier, then separate and dry to obtain the modified carrier; (2) Mix the nickel salt and alloy metal salt solution, add the modified carrier, stir and mix evenly, load the metallic nickel and alloy metal on the modified carrier, separate and dry to obtain the precursor; (3) In an N2 atmosphere, the precursor is heat-treated, cooled, cleaned and dried to obtain a carbon black-loaded nickel-based alloy material.
4. The preparation method according to claim 3, characterized in that, The oxidant is one or more of hydrogen peroxide, sodium hypochlorite, potassium hypochlorite, potassium dichromate, potassium permanganate, and sodium persulfate, and the concentration of the oxidant is preferably 0.5-1 mol / L; Preferably, the mass ratio of the carrier to the oxidant solution is 0.05-0.05:1; Preferably, in step (1), the modified carrier can be obtained by centrifugation, with a centrifugation speed of 2000-10000 rpm / min and a centrifugation time of 5-20 min; Preferably, in step (1), the carrier is immersed in the oxidant for 6-24 hours; Preferably, the stirring speed in step (1) is 200-1000 rpm / min, and the stirring time is 6-24 h; Preferably, the drying temperature in step (1) is 50-70℃ and the drying time is 2-8h.
5. The preparation method according to claim 3 or 4, characterized in that, In step (2), the nickel salt or alloy metal salt is dissolved in a polar solvent, which is one or more of ethanol, ethylene glycol, isopropanol, chloroform, and hexane. Preferably, in step (2), the stirring speed is 200-1000 rpm / min and the stirring time is 6-24 h; Preferably, step (2) is performed under ultrasonic conditions, with an ultrasonic power of 30-100W and an ultrasonic time of 0.5-2h. Preferably, in step (2), the nickel-based alloy support can be separated by rotary evaporation at a temperature of 50-70°C. Preferably, in step (2), the drying temperature is 50-70℃ and the drying time is 6-12h.
6. The preparation method according to any one of claims 3-5, characterized in that, Step (3) involves heat treatment at a temperature of 650-850℃ for 5-20 seconds, using a natural N2 atmosphere for cooling; and / or, In step (3), water and ethanol are used for alternating washing, the drying temperature is 50-70℃, and the drying time is 6-12h.
7. The nickel-based alloy catalyst according to any one of claims 1-6 is applied to the electrocatalytic production of ethylene from carbon dioxide.
8. A method for preparing ethylene, comprising the electrocatalytic reduction of CO2 to C2H4; wherein, In the electrocatalytic reaction, the cathode electrode is supported with the nickel-based alloy catalyst according to any one of claims 1-6.
9. The preparation method according to claim 8, characterized in that, The anode is a nickel electrode, preferably a nickel foam electrode; Preferably, the electrocatalysis is carried out in a gas diffusion electrode flow cell; Preferably, the electrolyte in the electrocatalytic process is an aqueous solution of KOH; Preferably, the cathode electrolyte and the anolyte are the same; Preferably, the cathode and anode are separated by a cation exchange membrane; Preferably, the CO2 gas flow rate in the electrocatalytic process is 10–30 sccm; Preferably, the current density is 100-500 mA / cm 2 .