WO2021195957A1 - 一种钴催化剂及其制备方法 - Google Patents

一种钴催化剂及其制备方法 Download PDF

Info

Publication number
WO2021195957A1
WO2021195957A1 PCT/CN2020/082418 CN2020082418W WO2021195957A1 WO 2021195957 A1 WO2021195957 A1 WO 2021195957A1 CN 2020082418 W CN2020082418 W CN 2020082418W WO 2021195957 A1 WO2021195957 A1 WO 2021195957A1
Authority
WO
WIPO (PCT)
Prior art keywords
cobalt
catalyst
carrier
preparation
cobalt catalyst
Prior art date
Application number
PCT/CN2020/082418
Other languages
English (en)
French (fr)
Inventor
谌春林
周振强
张建
Original Assignee
中国科学院宁波材料技术与工程研究所
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 中国科学院宁波材料技术与工程研究所 filed Critical 中国科学院宁波材料技术与工程研究所
Priority to US17/915,495 priority Critical patent/US20230220572A1/en
Priority to PCT/CN2020/082418 priority patent/WO2021195957A1/zh
Priority to EP20929417.2A priority patent/EP4129469A4/en
Publication of WO2021195957A1 publication Critical patent/WO2021195957A1/zh

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B11/00—Electrodes; Manufacture thereof not otherwise provided for
    • C25B11/04—Electrodes; Manufacture thereof not otherwise provided for characterised by the material
    • C25B11/051—Electrodes formed of electrocatalysts on a substrate or carrier
    • C25B11/055—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the substrate or carrier material
    • C25B11/057—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the substrate or carrier material consisting of a single element or compound
    • C25B11/061—Metal or alloy
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
    • B01J23/74—Iron group metals
    • B01J23/75—Cobalt
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J25/00—Catalysts of the Raney type
    • B01J35/23—
    • B01J35/33—
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/08—Heat treatment
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/20—Sulfiding
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/34—Irradiation by, or application of, electric, magnetic or wave energy, e.g. ultrasonic waves ; Ionic sputtering; Flame or plasma spraying; Particle radiation
    • B01J37/348—Electrochemical processes, e.g. electrochemical deposition or anodisation
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B11/00—Electrodes; Manufacture thereof not otherwise provided for
    • C25B11/02—Electrodes; Manufacture thereof not otherwise provided for characterised by shape or form
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B11/00—Electrodes; Manufacture thereof not otherwise provided for
    • C25B11/04—Electrodes; Manufacture thereof not otherwise provided for characterised by the material
    • C25B11/051—Electrodes formed of electrocatalysts on a substrate or carrier
    • C25B11/073—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material
    • C25B11/075—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material consisting of a single catalytic element or catalytic compound
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B15/00—Operating or servicing cells
    • C25B15/02—Process control or regulation
    • C25B15/023—Measuring, analysing or testing during electrolytic production
    • C25B15/025—Measuring, analysing or testing during electrolytic production of electrolyte parameters
    • C25B15/029—Concentration
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B15/00—Operating or servicing cells
    • C25B15/08—Supplying or removing reactants or electrolytes; Regeneration of electrolytes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
    • H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
    • H01M2004/027—Negative electrodes

Definitions

  • This application relates to a cobalt catalyst and a preparation method thereof.
  • cobalt itself has a certain catalytic performance, which is rich in reserves and low in price relative to precious metals.
  • Practical cobalt-based catalysts are mostly cobalt oxides, sulfides and borides, etc. The catalytic ability in some reactions is comparable to that of precious metals.
  • Cobalt-based catalysts are usually supported catalysts, which are prone to fall off and loss of active components during use, leading to gradual deactivation of the catalyst and difficulty in product separation and purification, which increases the operating steps and production costs of the entire process of the catalytic reaction.
  • the present application provides a cobalt catalyst and a preparation method thereof.
  • the catalytically active material grows on the surface of the cobalt-based substrate material, which improves the binding force of the active material on the carrier, and can prolong the service life of the catalyst and reduce the active composition. Points lost.
  • a cobalt catalyst in one aspect of this application, includes a carrier and a catalytically active material;
  • the carrier is a cobalt-based substrate material
  • the catalytically active substance grows on the surface of the carrier
  • the morphology of the catalytically active material is hydrangea-like nanospheres.
  • the catalytically active material uses the carrier as the cobalt source and grows on the surface of the carrier.
  • the cobalt-based base material is selected from at least one of cobalt foam, cobalt sheet, cobalt foil, and cobalt wire.
  • the diameter of the nanosphere is 100-500 nm.
  • the thickness of the surface sheet of the nanosphere is 1-10 nm.
  • the catalytically active substance is cobalt oxyhydroxide.
  • a method for preparing a cobalt catalyst is proposed.
  • the method at least includes:
  • step S100 is:
  • the dry powder and the carrier are heated and reacted in a protective gas atmosphere to obtain a precursor.
  • step a is: drying the sulfur source in an atmosphere of a certain flow of protective gas at a certain temperature for a certain period of time.
  • a certain temperature refers to 20°C ⁇ 40°C;
  • the protective gas is at least one of nitrogen, argon, and helium;
  • Shielding gas flow rate 50mL/min ⁇ 150mL/min;
  • the sulfur source is dried in a 100 mL/min nitrogen atmosphere at 30° C. for a certain period of time to remove the moisture content.
  • the drying time of the selected sulfur source there is no particular limitation on the drying time of the selected sulfur source.
  • the drying time is preferably 1h-5h.
  • the lotion is selected from at least one of absolute ethanol and acetone;
  • the washing method is: ultrasonic cleaning for 5 ⁇ 30min;
  • the drying conditions are: drying at 40°C ⁇ 60°C for 2h ⁇ 6h.
  • step b is: immersing the carrier in absolute ethanol for ultrasonic cleaning for 10 minutes, and then drying at 60° C. for 4 hours.
  • the carrier should be a cobalt-based material.
  • a carrier such as cobalt foam, cobalt sheet, and cobalt foil with its own supporting properties meets the above requirements.
  • a heating furnace is used as the reaction device.
  • the precursor is obtained through the vulcanization process.
  • the heating furnace is preferably a tube furnace with a built-in quartz tube or corundum tube, and the protective gas is preferably one of nitrogen, argon, and helium. Many kinds.
  • the flow rate of the shielding gas should not be too large, and the flow rate is preferably 10 mL/min to 100 mL/min. At this flow rate, the dry sulfur source powder can be prevented from being blown away directly, and the ablation of the product can be prevented, and the quality of the product is improved, thereby enhancing the mechanical and chemical properties of the product.
  • the upper limit of the flow rate of the shielding gas is independently selected from 60mL/min, 70mL/min, 80mL/min, 90mL/min, and 100mL/min; the lower limit of the flow rate of the shielding gas is independently selected from 10mL/min, 20mL/min, and 30mL/min. , 40mL/min, 50mL/min.
  • the mass ratio of the sulfur source to the carrier is 2-10:1;
  • the sulfur source is at least one of sublimed sulfur, sodium sulfide, and thiourea.
  • the upper limit of the mass ratio of the sulfur source to the carrier is independently selected from 4:1, 5:1, 7:1, 8:1, 10:1; the lower limit of the mass ratio of the sulfur source to the carrier is independently selected from 2:1, 3. :1, 3.8:1, 4.3:1, 5.4:1.
  • step S100 the temperature of the heating reaction is 300° C. to 400° C., and the reaction time is 0.25 h to 2 h;
  • the heating speed should not be too fast.
  • the heating rate of the heating reaction is 5°C/min-10°C/min.
  • the upper limit of the heating reaction temperature is independently selected from 350°C, 360°C, 370°C, 380°C, and 400°C; the lower limit of the heating reaction temperature is independently selected from 300°C, 310°C, 320°C, 330°C, and 340°C.
  • the upper limit of the reaction time is independently selected from 1h, 1.2h, 1.5h, 1.7h, and 2h; the lower limit of the reaction time is independently selected from 0.25h, 0.5h, 0.75h, 1h, and 1.25h.
  • the upper limit of the heating rate is independently selected from 7.5°C/min, 8°C/min, 8.5°C/min, 9°C/min, and 10°C/min; the lower limit of the heating rate is independently selected from 5°C/min, 5.5°C/min. min, 6°C/min, 6.5°C/min, 7°C/min.
  • step S200 is:
  • the precursor is used as an anode, electrically activated in an electrolyte, washed and dried to obtain a cobalt catalyst.
  • the precursor can be used as the anode, and the cathode and the reference electrode can be assembled to form a three-electrode electrolytic cell, which is electrically activated in the electrolyte, washed and dried to obtain a cobalt catalyst.
  • the cathode is: at least one of a graphite rod, a platinum wire, a platinum mesh, and a platinum sheet;
  • the reference electrode is any one of mercury/mercury oxide electrode, saturated calomel electrode, silver/silver chloride electrode;
  • the electrolyte is at least one of potassium hydroxide solution and sodium hydroxide solution;
  • the concentration of the electrolyte is 0.01M to 1M.
  • step S200 is: the precursor is used as the anode, the graphite rod is used as the cathode, and the mercury/mercury oxide electrode is used as the reference electrode to jointly assemble a three-electrode electrolytic cell, which is electrically activated in an electrolyte with a concentration of 1M, washed and dried. , The monolithic hydrangea-like cobalt oxyhydroxide nanosphere catalyst is obtained.
  • the upper limit of the electrolyte concentration is independently selected from 0.6M, 0.7M, 0.8M, 0.9M, and 1M; the lower limit of the electrolyte concentration is independently selected from 0.01M, 0.05M, 0.1M, 0.3M, and 0.5M.
  • the electro-activation method includes cyclic voltammetry, linear voltammetry, galvanostatic method, chronopotentiometry and other methods capable of applying positive potential oxidation to convert the cobalt sulfide precursor into cobalt oxyhydroxide.
  • the electro-activation speed should not be too fast, and the time should not be too short or too long.
  • the electro-activation parameter is: -0.3V vs. RHE ⁇ 1.4V vs. RHE voltage window, activation for 0.5h-4h.
  • the upper limit of the window voltage is independently selected from 0.8Vvs.RHE, 0.9Vvs.RHE, 1.0Vvs.RHE, 1.2Vvs.RHE, 1.4Vvs.RHE;
  • the lower limit of the window voltage is independently selected from -0.3V vs. RHE, -0.2V vs. RHE, -0.1V vs. RHE, 0.5V vs. RHE, 0.7V vs. RHE.
  • the upper limit of the activation time is independently selected from 2h, 2.5h, 3h, 3.5h, and 4h; the lower limit of the activation time is independently selected from 0.5h, 0.75h, 1h, 1.25h, and 1.5h.
  • the conditions for electro-activation by the constant current method are: set the current density to 0.1-100 mA/cm 2 , apply constant current to activate until the potential is stable, and activate for 1-60 min.
  • the upper limit of the current density is independently selected from 50mA/cm 2 , 60mA/cm 2 , 70mA/cm 2 , 80mA/cm 2 , and 100mA/cm 2 ;
  • the lower limit of the current density is independently selected from 0.1mA/cm 2 , 1mA/cm 2 cm 2 , 10mA/cm 2 , 20mA/cm 2 , 30mA/cm 2 .
  • the upper limit of the activation time is independently selected from 25 min, 30 min, 40 min, 50 min, and 60 min; the lower limit of the activation time is independently selected from 1 min, 5 min, 10 min, 15 min, and 20 min.
  • the conditions for the electrical activation of the chronopotentiometric method are: within the potential range of 1 to 1.6 V (relative to the reversible hydrogen electrode), the current is maintained for 1 to 60 minutes.
  • the upper limit of the potential range is independently selected from 1.3V, 1.35V, 1.4V, 1.5V, and 1.6V; the lower limit of the potential range is independently selected from 1.0V, 1.1V, 1.15V, 1.2V, and 1.25V.
  • the upper limit of the activation time is selected from 25 min, 30 min, 40 min, 50 min, and 60 min; the lower limit of the activation time is selected from 1 min, 5 min, 10 min, 15 min, and 20 min.
  • the surface of the catalyst obtained by activation is impregnated with a small amount of electrolyte.
  • a washing operation is required.
  • the washing method is: washing the catalyst with deionized water for 2 to 3 times. After the catalyst is washed, in order to prolong the service life of the catalyst, a drying operation is required.
  • the drying conditions are: drying at 40°C-60°C for 6h-12h.
  • the upper limit of the drying temperature is independently selected from 51°C, 53°C, 55°C, 57°C, and 60°C; the lower limit of the drying temperature is independently selected from 40°C, 42°C, 45°C, 48°C, and 50°C.
  • the upper limit of the drying time is independently selected from 9h, 10h, 10.5h, 11h, and 12h; the lower limit of the drying time is independently selected from 6h, 6.5h, 7h, 7.5h, and 8h.
  • the cobalt catalyst provided by this application has strong catalytic performance, the active components are not easy to agglomerate and fall off during the application process, and the catalyst is easy to separate after use.
  • the surface of the self-grown monolithic hydrangea-like nanosphere catalyst surface is a three-dimensional structure assembled by nanosheets, with a high specific surface area, which can fully expose the catalytic active sites , Improve catalytic efficiency.
  • the number and thickness of the surface sheets of the nanospheres can be controlled by adjusting the preparation conditions to provide effective mass transfer channels for different reactants to meet the needs of multiple reactions.
  • the nanosphere catalyst with a rough surface has better self-supporting properties, is not easy to agglomerate during the application process, and has a longer service life.
  • the preparation method of the cobalt catalyst provided by the present application induces the formation of nano-spherical morphology through vulcanization, and controls the number and size of nano-spheres by changing the vulcanization conditions, and then activates them into hydrangea-like cobalt oxyhydroxide nano-spheres without
  • the addition of additional templates saves costs and is innovative.
  • the preparation method of the cobalt catalyst provided by this application has abundant raw materials, simple operation, high production efficiency, and the product prepared by the method has high yield and low cost.
  • Figure 1 is a scanning electron microscope image of the self-grown monolithic hydrangea-like cobalt oxyhydroxide catalyst prepared in Example 1 of the application, with a scale of 500 ⁇ m;
  • Example 2 is a scanning electron micrograph of the self-grown monolithic hydrangea-like cobalt oxyhydroxide catalyst prepared in Example 1 of the application, and the scale bar is 20 ⁇ m;
  • Figure 3 is a scanning electron microscope image of the self-grown monolithic hydrangea-like cobalt oxyhydroxide catalyst prepared in Example 1 of the application, with a scale of 1 ⁇ m;
  • FIG. 4 is a distribution diagram of EDX elements of the self-grown monolithic hydrangea-like cobalt oxyhydroxide catalyst prepared in Example 1 of the application; wherein (a) is cobalt element and (b) is oxygen element;
  • Example 5 is a transmission electron microscope image of the self-grown monolithic hydrangea-like cobalt oxyhydroxide catalyst prepared in Example 1 of the application; wherein (a) the scale bar is 50 nm, and (b) the scale bar is 10 nm;
  • FIG. 7 is a schematic diagram of the device structure in Embodiment 11 of this application.
  • FIG. 8 is a graph of anodic current density-voltage of different electrolytes in a three-electrode system using sample 1 as an anode catalyst prepared in Example 1 of this application;
  • Example 10 is a graph of current density-voltage under different electrolyte conditions in a dual-electrode system where sample 1 prepared in Example 1 of the application is used as a cathode catalyst and an anode catalyst at the same time;
  • FIG. 11 is a graph showing the concentration-electrical quantity of the raw material BHMF and the anode product in a two-electrode system where the sample 1 prepared in Example 1 is used as a cathode catalyst and an anode catalyst at the same time.
  • the HITACHI S-4800 scanning electron microscope was used for EDX analysis at 20.0kV.
  • the FEI F20 transmission electron microscope was used for TEM analysis at 200kV.
  • the FEI F20 transmission electron microscope was used for the selected area electron diffraction analysis at 200kV.
  • step (3) Put the dry sublimated sulfur powder obtained in step (1) and the cobalt foam obtained in step (2) together in the corundum boat of the tube furnace, and then pass in high-purity nitrogen gas as a full protective gas after sealing.
  • the flow rate is 50mL/min; the temperature is raised to 350°C at a rate of 5°C/min, after holding for 0.5h, it is naturally cooled to room temperature to obtain the precursor.
  • the mass ratio of sublimated sulfur powder to cobalt foam is 5.4:1.
  • step (3) The precursor obtained in step (3) is used as the anode, the graphite rod is used as the cathode, the mercury/mercury oxide electrode is used as the reference electrode, and the three-electrode electrolytic cell is assembled together, which is circulated in a potassium hydroxide solution with a concentration of 1M Voltammetry was activated under the voltage window of -0.3V vs.RHE ⁇ 1.4V vs.RHE for 1h, rinsed with deionized water twice, dried at 60°C for 10h, and obtained self-grown monolithic hydrangea-like cobalt oxyhydroxide Nanosphere catalyst, denoted as sample 1.
  • step (3) Put the dry sublimated sulfur powder obtained in step (1) and the cobalt foam obtained in step (2) together in the corundum boat of the tube furnace, and then pass in high-purity nitrogen gas as a full protective gas after sealing.
  • the flow rate is 50mL/min; the temperature is raised to 350°C at a rate of 5°C/min, after holding for 0.5h, it is naturally cooled to room temperature to obtain the precursor.
  • the mass ratio of sublimated sulfur powder to cobalt foam is 3:1.
  • step (3) The precursor obtained in step (3) is used as the anode, the graphite rod is used as the cathode, the mercury/mercury oxide electrode is used as the reference electrode, and a three-electrode electrolytic cell is assembled together, and it is circulated in a potassium hydroxide solution with a concentration of 1M. Voltammetry was activated under the voltage window of -0.3V vs.RHE ⁇ 1.4V vs.RHE for 1h, rinsed with deionized water twice, dried at 60°C for 10h, and obtained self-grown monolithic hydrangea-like cobalt oxyhydroxide Nanosphere catalyst, denoted as sample 2.
  • Example 1 Compared with Example 1, the quality of the carrier used in this example has changed, and the rest of the preparation conditions are unchanged. With the increase of the carrier quality, the number of cobalt oxyhydroxide nanospheres of the finally obtained catalyst decreases.
  • step (3) Put the dry sublimated sulfur powder obtained in step (1) and the cobalt foam obtained in step (2) together in a corundum boat of a tube furnace, and then pass in high-purity nitrogen gas as a full protective gas after sealing.
  • the flow rate is 50 mL/min; the temperature is raised to 350° C. at a rate of 5° C./min, and after holding for 0.5 h, it is naturally cooled to room temperature to obtain a precursor.
  • the mass ratio of sublimated sulfur powder to cobalt foam is 2:1.
  • step (3) The precursor obtained in step (3) is used as the anode, the graphite rod is used as the cathode, the mercury/mercury oxide electrode is used as the reference electrode, and a three-electrode electrolytic cell is assembled together, and it is circulated in a potassium hydroxide solution with a concentration of 1M. Voltammetry was activated under the voltage window of -0.3V vs.RHE ⁇ 1.4V vs.RHE for 1h, rinsed with deionized water twice, dried at 60°C for 10h, and obtained self-grown monolithic hydrangea-like cobalt oxyhydroxide Nanosphere catalyst, denoted as sample 3.
  • Example 1 Compared with Example 1, the quality of the sulfur source used in this example has changed, and the rest of the preparation conditions are unchanged. As the quality of the sulfur source decreases, the number of cobalt oxyhydroxide nanospheres in the finally obtained catalyst decreases.
  • step (3) Put the dry sublimated sulfur powder obtained in step (1) and the cobalt foam obtained in step (2) together in the corundum boat of the tube furnace, and then pass in high-purity nitrogen gas as a full protective gas after sealing.
  • the flow rate is 100 mL/min; the temperature is raised to 350° C. at a rate of 5° C./min, and after holding for 1 hour, it is naturally cooled to room temperature to obtain a precursor.
  • the mass ratio of sublimated sulfur powder to cobalt foam is 4.3:1.
  • step (3) The precursor obtained in step (3) is used as the anode, the graphite rod is used as the cathode, the mercury/mercury oxide electrode is used as the reference electrode, and the three-electrode electrolytic cell is assembled together, which is circulated in a potassium hydroxide solution with a concentration of 1M Voltammetry was activated under the voltage window of -0.3V vs.RHE ⁇ 1.4V vs.RHE for 1.5h, rinsed with deionized water twice, dried at 60°C for 12h, and obtained self-grown monolithic hydrangea-like hydroxyl oxidation Cobalt nanosphere catalyst, denoted as sample 4.
  • step (3) Put the dry sodium sulfide powder obtained in step (1) and the cobalt foam obtained in step (2) together in the corundum boat of the tube furnace, and then pass in high-purity argon gas as a full protective gas after sealing.
  • the gas flow rate is 50mL/min; the temperature is raised to 350°C at a rate of 5°C/min, after holding for 0.5h, it is naturally cooled to room temperature to obtain the precursor.
  • the mass ratio of sodium sulfide powder to cobalt foam is 4:1.
  • step (3) The precursor obtained in step (3) is used as the anode, the graphite rod is used as the cathode, the mercury/mercury oxide electrode is used as the reference electrode, and the three-electrode electrolytic cell is assembled together, which is circulated in a sodium hydroxide solution with a concentration of 1M Voltammetry was activated under the voltage window of -0.3V vs.RHE ⁇ 1.4V vs.RHE for 1h, rinsed with deionized water for 3 times, dried at 60°C for 10h, and obtained self-grown monolithic hydrangea-like cobalt oxyhydroxide Nanosphere catalyst, denoted as sample 5.
  • step (3) Put the dry thiourea powder obtained in step (1) and the cobalt foam obtained in step (2) together in a corundum boat of a tube furnace, and then pass in high-purity argon as a full protective gas after sealing.
  • the gas flow rate is 40 mL/min; the temperature is increased to 300° C. at a rate of 6.5° C./min, and after holding for 1 hour, it is naturally cooled to room temperature to obtain the precursor.
  • the mass ratio of thiourea powder to cobalt foam is 3:1.
  • step (3) The precursor obtained in step (3) is used as the anode, the graphite rod is used as the cathode, the mercury/mercury oxide electrode is used as the reference electrode, and a three-electrode electrolytic cell is assembled together, and it is circulated in a potassium hydroxide solution with a concentration of 1M. Voltammetry was activated under the voltage window of -0.3V vs.RHE ⁇ 1.4V vs.RHE for 2h, rinsed with deionized water 3 times, dried at 60°C for 8h, and obtained self-grown monolithic hydrangea-like cobalt oxyhydroxide Nanosphere catalyst, denoted as sample 6.
  • step (3) Put the dry sublimated sulfur powder obtained in step (1) and the cobalt flakes obtained in step (2) together in the corundum boat of the tube furnace, and then pass in high-purity argon as the full protective gas after sealing.
  • the gas flow rate is 80mL/min; the temperature is raised to 400°C at a rate of 8°C/min, after holding for 0.5h, it is naturally cooled to room temperature to obtain the precursor.
  • the mass ratio of sublimated sulfur powder to cobalt flakes is 3.8:1.
  • step (3) The precursor obtained in step (3) is used as the anode, the graphite rod is used as the cathode, the mercury/mercury oxide electrode is used as the reference electrode, and a three-electrode electrolytic cell is assembled together, and it is circulated in a potassium hydroxide solution with a concentration of 1M. Voltammetry was activated under the voltage window of -0.3V vs.RHE ⁇ 1.4V vs.RHE for 2h, rinsed with deionized water for 3 times, dried at 60°C for 8h, and obtained self-grown monolithic hydrangea-like cobalt oxyhydroxide Nanosphere catalyst, denoted as sample 7.
  • step (3) Put the dry sublimated sulfur powder obtained in step (1) and the cobalt foil obtained in step (2) together in a corundum boat of a tube furnace, and then pass high-purity argon gas as a full protective gas after sealing.
  • the gas flow rate is 50mL/min; the temperature is raised to 350°C at a rate of 7°C/min, and after holding for 1 hour, it is naturally cooled to room temperature to obtain the precursor.
  • the mass ratio of sublimated sulfur powder to cobalt foil is 3:1.
  • step (3) The precursor obtained in step (3) is used as the anode, the graphite rod is used as the cathode, and the mercury/mercury oxide electrode is used as the reference electrode. A current density of 5mA/cm 2 is applied to the electric current. After the electric potential is stable and maintained for 10 minutes, it is washed twice with deionized water and dried at 50°C for 12 hours to obtain self-growing monolithic hydrangea-like cobalt oxyhydroxide nanospheres. Catalyst, denoted as sample 8.
  • step (3) Put the dry sublimated sulfur powder obtained in step (1) and the cobalt flakes obtained in step (2) together in the corundum boat of the tube furnace, and then pass in high-purity argon as the full protective gas after sealing.
  • the gas flow rate is 60mL/min; the temperature is raised to 380°C at a rate of 5°C/min, and after holding for 1 hour, it is naturally cooled to room temperature to obtain the precursor.
  • the mass ratio of sublimed sulfur powder to cobalt flakes is 3:1.
  • step (3) The precursor obtained in step (3) is used as the anode, the graphite rod is used as the cathode, and the mercury/mercury oxide electrode is used as the reference electrode to form a three-electrode electrolytic cell.
  • the time is measured in a potassium hydroxide solution with a concentration of 1M After the potentiometric method was activated under a voltage window of 1.4V (relative to the reversible hydrogen electrode) for 60 minutes, rinsed with deionized water 3 times and dried at 40°C for 12 hours to obtain a self-grown monolithic hydrangea-like cobalt oxyhydroxide nanosphere catalyst. Recorded as sample 9.
  • Samples 1 to 9 were tested by SEM, EDX and TEM.
  • Figure 1 is a scanning electron microscope image of sample 1. It can be seen from the figure that the microstructure of the catalyst is hydrangea-like nanospheres, and the surface of the nanospheres is composed of a three-dimensional structure assembled from nanosheets, which has good mechanical properties.
  • Figure 2 is the element distribution diagram of the EDX test of sample 1. It can be seen from the figure that the cobalt and oxygen are uniformly distributed.
  • Figure 3 is a transmission electron micrograph of sample 1. It can be seen from the figure that the surface of the nanosphere of the catalyst is composed of a three-dimensional structure assembled by nanosheets, and the characterization results are consistent with the scanning electron micrograph results.
  • Figure 4 shows the selected area electron diffraction pattern of sample 1.
  • the electron diffraction rings in the figure correspond to (0 0 2), (2 4 0), (1 4 0), (0 2 1) of the cobalt oxyhydroxide standard card 26-0480. It is proved that the catalyst phase is cobalt oxyhydroxide.
  • SEM images, element distribution images, and TEM images of samples 2 to 9 are similar to those of sample 1, except for the difference between the number of nanospheres and the size of the nanospheres.
  • Preparation of working electrode Prepare working electrodes by fixing samples 1 to 9 and pure cobalt foam through stainless steel electrode clamps.
  • Counter electrode Use a graphite rod as the counter electrode.
  • the working electrode is used as the anode
  • the counter electrode is used as the cathode
  • the mercury/mercury oxide electrode is used as the reference electrode, fixed in a PTFE plug and fixed on a 10mL reaction cell.
  • Two-electrode symmetric electrolysis cell the cathode and anode are two identical working electrodes, and the reactor volume is more than 10 mL.
  • the assembled two-electrode system was used to control the voltage of the electrolytic cell to 1.7V, and the electrocatalytic performance was tested with potassium hydroxide (1M) solution and 10mM BHMF potassium hydroxide (1M) solution.
  • the test device is shown in Figure 7.
  • An electrolytic cell including a power source 1, an electrolyte 4, an anode 2, a cathode 3, and a current loop is constructed.
  • the electrolyte is placed in a closed reactor, and the gas generated by the cathode is introduced into the gas through the gas pipe 5. Collect the device and use the drainage method to obtain the gas volume.
  • the gas collection device includes a measuring cylinder 6 filled with water and standing upside down in a water tank 7 containing water 8, and the outlet of the air duct is located in the measuring cylinder 6.
  • the electrolyte is a 10mM potassium hydroxide (1M) solution of BHMF, only a lower voltage is required to drive the coupling reaction.
  • Samples 1 to 9 were used as anode catalysts to conduct electrocatalytic oxidation of 2,5-furandimethanol (BHMF) to prepare 2,5-furandicarboxylic acid (FDCA).
  • BHMF 2,5-furandimethanol
  • FDCA 2,5-furandicarboxylic acid
  • the catalytic effects of each sample were similar, and they all had good catalytic effects.
  • a typical example is sample 1 for illustration.
  • Figure 8 shows that in the three-electrode system, the self-grown monolithic hydrangea-like cobalt oxyhydroxide nanosphere catalyst is used as the anode catalyst, and has better oxygen evolution performance than pure foamed cobalt as the anode.
  • the voltage is lower and the curve is closer to the Y axis), used for electrocatalytic oxidation of 2,5-furandimethanol (BHMF) to prepare 2,5-furandicarboxylic acid (FDCA).
  • BHMF 2,5-furandimethanol
  • FDCA 2,5-furandicarboxylic acid
  • Figure 9 shows that in the three-electrode system, the self-grown monolithic hydrangea-like cobalt oxyhydroxide nanosphere catalyst also has far better than pure foamed cobalt as the cathode in the electrolysis of water hydrogen production capacity (that is to achieve the same current density required voltage Lower, the curve is closer to the Y axis), the addition of 10mM BHMF to the electrolyte has no significant effect on its hydrogen production performance (the curve has no obvious deviation and basically overlaps), indicating that the catalyst has high hydrogen evolution reaction selectivity.
  • the sample hydrangea-like cobalt oxyhydroxide nanosphere catalyst prepared in Example 1 was used as a cathode catalyst and an anode catalyst to form a two-electrode symmetrical electrolytic cell.
  • the electrocatalytic reaction was carried out in a BHMF-free electrolyte and a 10mM BHMF electrolyte.
  • the sample hydrangea-like cobalt oxyhydroxide nanosphere catalyst prepared in Example 1 was used as a cathode catalyst and an anode catalyst to assemble a two-electrode symmetric electrolytic cell, electrocatalytic oxidation of BHMF to prepare FDCA, the result is shown in Figure 11, the anode product includes HMF, FDCA, HMFCA, FFCA and DFF.
  • the concentration of HMF, HMFCA, FFCA and DFF at the end of the reaction is extremely low, indicating that the catalyst has high selectivity to FDCA.
  • the high selectivity of FDCA not only guarantees the high purity of the product , And make the product yield very high.
  • the FDCA Faraday efficiency is close to 100%, the energy utilization rate is high, and there is almost no energy waste.

Abstract

本申请公开了一种钴催化剂及其制备方法，所述钴催化剂包括载体和催化活性物质；载体为钴基基底材料；催化活性物质生长于载体表面；催化活性物质的形貌为绣球花状纳米球。本申请催化剂为自源生长的整体式纳米球催化剂，催化剂表面为纳米片组装而成的三维结构，比表面积高，能够充分暴露催化活性位点，提升催化效率。与纳米线状催化剂相比，本申请催化剂具有更好的自支撑性，活性组分不易在应用过程中发生集聚和脱落，具有更长的使用寿命。

Description

一种钴催化剂及其制备方法 技术领域
本申请涉及一种钴催化剂及其制备方法。
背景技术
贵金属具有优异的催化性能，是催化领域中的明星。但诸如钯、铂、金、钌、铱等贵金属可用储量有限，而且价格高昂，因此大规模使用贵金属进行工业催化并不是长久之计。面对上述问题，人们将目光聚焦到具有多种价态的过渡金属的开发利用中。
钴作为过渡金属之一，本身具有一定的催化性能，相对于贵金属储量丰富、价格低廉。实用钴基催化剂多为钴的氧化物、硫化物和硼化物等，在某些反应中催化能力可与贵金属媲美。
钴基催化剂通常为负载型催化剂，使用过程中容易发生活性组分的脱落与流失，导致催化剂逐步失活，并引起产物分离纯化困难，增加了催化反应整个过程的操作步骤和生产成本。
发明内容
为了解决上述技术问题，本申请提供了一种钴催化剂及其制备方法，催化活性物质生长于钴基基底材料表面，提高了活性物质在载体上的结合力，可以延长催化剂使用寿命和降低活性组分流失。
为实现上述目的，本申请采用的技术方案如下：
本申请一方面，提出了一种钴催化剂，所述钴催化剂包括载体和催化活性物质；
载体为钴基基底材料；
催化活性物质生长于载体表面；
催化活性物质的形貌为绣球花状纳米球。
可选地，催化活性材料以载体为钴源、自源生长在载体表面。
可选地，钴基基底材料选自钴泡沫、钴片、钴箔、钴丝中的至少 一种。
可选地，纳米球直径为100～500nm。
可选地，纳米球表面片层厚度为1～10nm。
可选地，催化活性物质为羟基氧化钴。
本申请另一方面，提出了一种钴催化剂的制备方法，所述方法至少包括：
S100、将载体和硫源在保护气体气氛中，加热反应，得到前驱体；
S200、将前驱体在电解液中，电活化，得到所述钴催化剂。
可选地，步骤S100为：
a、获得作为硫源的干燥粉末；
b、将载体浸没于洗液中，洗涤，干燥；
c、将干燥粉末与载体在保护气体的气氛中，加热反应，得到前驱体。
具体地，步骤a为：将硫源在一定温度下于一定流量的保护气体的气氛中干燥一定时间。
其中一定温度是指20℃～40℃；
保护气体为氮气、氩气、氦气中的至少一种；
保护气体流量为：50mL/min～150mL/min；
优选地，将硫源在30℃下于100mL/min氮气气氛中干燥一定时间，去除所含水分。
本申请中，对于所选硫源的干燥时间没有特殊限定。为了制备出性能优异的整体式绣球花状羟基氧化钴纳米球催化剂，保证产品纯度，较佳地，干燥时间为1h～5h。
具体地，步骤b中，洗液选自无水乙醇、丙酮中的至少一种；
洗涤方式为：超声清洗5～30min；
干燥条件为：40℃～60℃下干燥2h～6h。
优选地，步骤b为：将载体浸没于无水乙醇中超声清洗10min，然后在60℃下干燥4h。
为了成功制备出整体式催化剂，载体应为钴基材料，较佳地，自 身具有支撑性的钴泡沫、钴片、钴箔等载体满足上述要求。
具体地，步骤S100采用加热炉作为反应装置。本步骤通过硫化过程得到前驱体，其中，为方便保护气体的通入，加热炉优选为内置石英管或刚玉管的管式炉，保护气体优选为氮气、氩气和氦气中的一种或多种。保护气体的流量不宜过大，其流量优选为10mL/min～100mL/min。该流量下，既能防止干燥的硫源粉末被直接吹离，又能防止产物的烧蚀，提高了产物的质量，进而增强了产物的机械性能与化学性能。
具体地，保护气体的流量上限独立选自60mL/min、70mL/min、80mL/min、90mL/min、100mL/min；保护气体的流量下限独立选自10mL/min、20mL/min、30mL/min、40mL/min、50mL/min。
可选地，在步骤S100中，硫源与载体的质量比为2～10:1；
优选地，硫源为升华硫、硫化钠和硫脲中的至少一种。
具体地，硫源与载体的质量比上限独立选自4:1、5:1、7:1、8:1、10:1；硫源与载体的质量比下限独立选自2:1、3:1、3.8:1、4.3:1、5.4:1。
可选地，在步骤S100中，所述加热反应的温度为300℃～400℃，反应时间为0.25h～2h；
为保证产物质量，加热速度不宜过快，优选地，所述加热反应的升温速率为5℃/min～10℃/min。
具体地，加热反应温度的上限独立选自350℃、360℃、370℃、380℃、400℃；加热反应温度的下限独立选自300℃、310℃、320℃、330℃、340℃。
具体地，反应时间的上限独立选自1h、1.2h、1.5h、1.7h、2h；反应时间的下限独立选自0.25h、0.5h、0.75h、1h、1.25h。
具体地，升温速率的上限独立选自7.5℃/min、8℃/min、8.5℃/min、9℃/min、10℃/min；升温速率的下限独立选自5℃/min、5.5℃/min、6℃/min、6.5℃/min、7℃/min。
可选地，步骤S200为：
将前驱体作为阳极，在电解液中电活化，洗涤、干燥后，得到钴催化剂。
具体地，可以将前驱体作为阳极，与阴极、参比电极，组装成三电极电解池，在电解液中电活化，洗涤、干燥后，得到钴催化剂。
可选地，阴极为：石墨棒、铂丝、铂网、铂片中的至少一种；
参比电极为：汞/氧化汞电极、饱和甘汞电极、银/氯化银电极中的任意一种；
电解液为氢氧化钾溶液、氢氧化钠溶液中的至少一种；
电解液的浓度为0.01M～1M。
优选地，步骤S200为：前驱体作为阳极，石墨棒作为阴极，汞/氧化汞电极作为参比电极，共同组装成三电极电解池，在浓度为1M的电解液中电活化，洗涤、干燥后，得到整体式绣球花状羟基氧化钴纳米球催化剂。
具体地，电解液浓度的上限独立选自0.6M、0.7M、0.8M、0.9M、1M；电解液浓度的下限独立选自0.01M、0.05M、0.1M、0.3M、0.5M。
步骤S200中，电活化方法包括循环伏安法、线性伏安法、恒电流法、计时电位法等能够施加正电位氧化，将硫化钴前驱体转变为羟基氧化钴的方法。为保证产品催化性能和稳定性，电活化速度不宜过快、时间不宜过短或过长。
优选地，采用循环伏安法或线性伏安法，较佳地，电活化参数为：-0.3V vs.RHE～1.4V vs.RHE电压窗口下，活化0.5h～4h。
具体地，窗口电压的上限独立选自0.8V vs.RHE、0.9V vs.RHE、1.0V vs.RHE、1.2V vs.RHE、1.4V vs.RHE；窗口电压的下限独立选自-0.3V vs.RHE、-0.2V vs.RHE、-0.1V vs.RHE、0.5V vs.RHE、0.7V vs.RHE。
具体地，活化时间的上限独立选自2h、2.5h、3h、3.5h、4h；活化时间的下限独立选自0.5h、0.75h、1h、1.25h、1.5h。
优选地，恒电流法电活化的条件为：设定电流密度为0.1～100mA/cm 2，通入恒电流活化至电势稳定，活化1～60min。
具体地，电流密度的上限独立选自50mA/cm 2、60mA/cm 2、70mA/cm 2、80mA/cm 2、100mA/cm 2；电流密度的下限独立选自0.1mA/cm 2、1mA/cm 2、10mA/cm 2、20mA/cm 2、30mA/cm 2。
具体地，活化时间的上限独立选自25min、30min、40min、50min、60min；活化时间的下限独立选自1min、5min、10min、15min、20min。
优选地，所述计时电位法电活化的条件为：在1～1.6V(相对于可逆氢电极)电位范围内，保持通入电流，并保持1～60min。
具体地，电位范围上限独立选自1.3V、1.35V、1.4V、1.5V、1.6V；电位范围下限独立选自1.0V、1.1V、1.15V、1.2V、1.25V。
具体地，活化时间的上限选自25min、30min、40min、50min、60min；活化时间的下限选自1min、5min、10min、15min、20min。
活化得到的催化剂表面浸有少量电解液，为去除电解液，需进行洗涤操作，较佳地，洗涤方法为：将所述催化剂使用去离子水冲洗2～3次。催化剂冲洗完后，为延长催化剂使用寿命，需进行烘干操作。
可选地，干燥条件为：40℃～60℃下干燥6h～12h。
具体地，干燥温度的上限独立选自51℃、53℃、55℃、57℃、60℃；干燥温度的下限独立选自40℃、42℃、45℃、48℃、50℃。
具体地，干燥时间的上限独立选自9h、10h、10.5h、11h、12h；干燥时间的下限独立选自6h、6.5h、7h、7.5h、8h。
本申请的有益效果在于：
1)本申请所提供的钴催化剂催化性能强，活性组分不易在应用过程中发生集聚和脱落，催化剂用后易分离。
2)本申请所提供的自源生长的整体式钴催化剂，自源生长的整体式绣球花状纳米球催化剂表面为纳米片组装而成的三维结构，比表面积高，能够充分暴露催化活性位点，提升催化效率。同时，可以通过制备条件的调整来控制纳米球表面片层的数量以及厚度，为不同反应物提供有效传质通道以满足多种反应的需要。与纳米线状催化剂相比，带有粗糙表面的纳米球催化剂具有更好的自支撑性，不易在应用过程中发生集聚，具有更长的使用寿命。
3)本申请所提供的钴催化剂的制备方法，通过硫化诱导纳米球状形貌的生成，通过硫化条件的改变控制纳米球数量、大小的改变，随后活化为绣球花状羟基氧化钴纳米球，无需额外模板的加入，节约 了成本，具有创新性。
4)本申请所提供的钴催化剂的制备方法，原料丰富，操作简单，生产效率高，而且采用该方法制备出的产品产量高，成本低。
附图说明
图1为本申请实施例1中制得的自源生长的整体式绣球花状羟基氧化钴催化剂的扫描电镜图，比例尺为500μm；
图2为本申请实施例1中制得的自源生长的整体式绣球花状羟基氧化钴催化剂的扫描电镜图，比例尺为20μm；
图3为本申请实施例1中制得的自源生长的整体式绣球花状羟基氧化钴催化剂的扫描电镜图，比例尺为1μm；
图4为本申请实施例1中制得的自源生长的整体式绣球花状羟基氧化钴催化剂的EDX元素分布图；其中，(a)为钴元素，(b)为氧元素；
图5为本申请实施例1中制得的自源生长的整体式绣球花状羟基氧化钴催化剂的透射电镜图；其中，(a)比例尺为50nm，(b)比例尺为10nm；
图6为本申请实施例1中制得的自源生长的整体式绣球花状羟基氧化钴催化剂的选区电子衍射图；
图7为本申请实施例11中的装置结构示意图；
图8为本申请实施例1制得的样品1作为阳极催化剂三电极体系中不同电解液阳极电流密度-电压图；
图9为本申请实施例1制得的样品1作为阴极催化剂三电极体系中不同电解液阴极电流密度-电压图；
图10为本申请实施例1制得的样品1同时作为阴极催化剂和阳极催化剂双电极体系中不同电解液条件下电流密度-电压图；
图11为本申请实施例1制得的样品1同时作为阴极催化剂和阳极催化剂在两电极体系中原料BHMF和阳极产物浓度-电量图。
部件和附图标记列表：
1、电源；2、阳极；3、阴极；4、电解液；5、导气管；6、量筒；7、水槽；8、水。
具体实施方式
下面结合附图和具体实施例，进一步阐述本申请。
下述实施例中所使用的实验方法如无特殊说明，均为常规方法；下述实施例中所用的试剂、材料等，如无特殊说明，均可从商业途径得到。下述实施例中所用的仪器，如无特殊说明，使用时采用的参数均为厂家推荐参数。
实施例中样品分析所采用的仪器和参数如下：
利用HITACHI S-4800扫描电子显微镜在8.0kV下进行SEM分析。
利用HITACHI S-4800扫描电子显微镜在20.0kV下进行EDX分析。
利用FEI F20透射电子显微镜在200kV下进行TEM分析。
利用FEI F20透射电子显微镜在200kV下进行选区电子衍射分析。
实施例1
(1)将1500mg升华硫粉末置于管式炉的刚玉舟里，密封后在30℃下于100mL/min氮气气氛中干燥2h，去除所含水分。
(2)将280mg钴泡沫浸没于无水乙醇中超声清洗10min，然后再60℃下干燥4h。
(3)将步骤(1)得到的干燥升华硫粉末与步骤(2)中得到的钴泡沫共同置于管式炉的刚玉舟里，密封后通入高纯氮气作为全程保护气，其中氮气的流量为50mL/min；以5℃/min的速度升温至350℃，保温0.5h后，自然冷却至室温，得到前驱体。其中，升华硫粉末与钴泡沫质量比为5.4：1。
(4)将步骤(3)得到的前驱体作为阳极，石墨棒作为阴极，汞/氧化汞电极作为参比电极，共同组装成三电极电解池，在浓度为1M的氢氧化钾溶液中以循环伏安法在-0.3V vs.RHE～1.4V vs.RHE电压 窗口下活化1h后，用去离子水冲洗2次，在60℃干燥10h后得到自源生长的整体式绣球花状羟基氧化钴纳米球催化剂，记为样品1。
实施例2
(1)将1500mg升华硫粉末置于管式炉的刚玉舟里，密封后在30℃下于100mL/min氮气气氛中干燥2h，去除所含水分。
(2)将500mg钴泡沫浸没于无水乙醇中超声清洗10min，然后再60℃下干燥4h。
(3)将步骤(1)得到的干燥升华硫粉末与步骤(2)中得到的钴泡沫共同置于管式炉的刚玉舟里，密封后通入高纯氮气作为全程保护气，其中氮气的流量为50mL/min；以5℃/min的速度升温至350℃，保温0.5h后，自然冷却至室温，得到前驱体。其中，升华硫粉末与钴泡沫质量比为3：1。
(4)将步骤(3)得到的前驱体作为阳极，石墨棒作为阴极，汞/氧化汞电极作为参比电极，共同组装成三电极电解池，在浓度为1M的氢氧化钾溶液中以循环伏安法在-0.3V vs.RHE～1.4V vs.RHE电压窗口下活化1h后，用去离子水冲洗2次，在60℃干燥10h后得到自源生长的整体式绣球花状羟基氧化钴纳米球催化剂，记为样品2。
与实施例1相比，本实施例所使用的载体质量发生了变化，其余制备条件均未改变，随着载体质量的增加，最终得到的催化剂的羟基氧化钴纳米球数量变少。
实施例3
(1)将500mg升华硫粉末置于管式炉的刚玉舟里，密封后在30℃下于100mL/min氮气气氛中干燥2h，去除所含水分。
(2)将250mg钴泡沫浸没于无水乙醇中超声清洗10min，然后再60℃下干燥4h。
(3)将步骤(1)得到的干燥升华硫粉末与步骤(2)中得到的钴泡沫共同置于管式炉的刚玉舟里，密封后通入高纯氮气作为全程保护气，其中氮气的流量为50mL/min；以5℃/min的速度升温至350℃， 保温0.5h后，自然冷却至室温，得到前驱体。其中，升华硫粉末与钴泡沫质量比为2：1。
(4)将步骤(3)得到的前驱体作为阳极，石墨棒作为阴极，汞/氧化汞电极作为参比电极，共同组装成三电极电解池，在浓度为1M的氢氧化钾溶液中以循环伏安法在-0.3V vs.RHE～1.4V vs.RHE电压窗口下活化1h后，用去离子水冲洗2次，在60℃干燥10h后得到自源生长的整体式绣球花状羟基氧化钴纳米球催化剂，记为样品3。
与实施例1相比，本实施例所使用的硫源质量发生了变化，其余制备条件均未改变，随着硫源质量的减少，最终得到的催化剂的羟基氧化钴纳米球数量变少。
实施例4
(1)将1500mg升华硫粉末置于管式炉的刚玉舟里，密封后在30℃下于100mL/min氮气气氛中干燥4h，去除所含水分。
(2)将350mg钴泡沫浸没于无水乙醇中超声清洗10min，然后再60℃下干燥4h。
(3)将步骤(1)得到的干燥升华硫粉末与步骤(2)中得到的钴泡沫共同置于管式炉的刚玉舟里，密封后通入高纯氮气作为全程保护气，其中氮气的流量为100mL/min；以5℃/min的速度升温至350℃，保温1h后，自然冷却至室温，得到前驱体。其中，升华硫粉末与钴泡沫质量比为4.3：1。
(4)将步骤(3)得到的前驱体作为阳极，石墨棒作为阴极，汞/氧化汞电极作为参比电极，共同组装成三电极电解池，在浓度为1M的氢氧化钾溶液中以循环伏安法在-0.3V vs.RHE～1.4V vs.RHE电压窗口下活化1.5h后，用去离子水冲洗2次，在60℃干燥12h后得到自源生长的整体式绣球花状羟基氧化钴纳米球催化剂，记为样品4。
实施例5
(1)将1000mg硫化钠粉末置于管式炉的刚玉舟里，密封后在30℃下于100mL/min氮气气氛中干燥5h，去除所含水分。
(2)将250mg钴泡沫浸没于无水乙醇中超声清洗10min，然后再60℃下干燥4h。
(3)将步骤(1)得到的干燥硫化钠粉末与步骤(2)中得到的钴泡沫共同置于管式炉的刚玉舟里，密封后通入高纯氩气作为全程保护气，其中氩气的流量为50mL/min；以5℃/min的速度升温至350℃，保温0.5h后，自然冷却至室温，得到前驱体。其中，硫化钠粉末与钴泡沫质量比为4：1。
(4)将步骤(3)得到的前驱体作为阳极，石墨棒作为阴极，汞/氧化汞电极作为参比电极，共同组装成三电极电解池，在浓度为1M的氢氧化钠溶液中以循环伏安法在-0.3V vs.RHE～1.4V vs.RHE电压窗口下活化1h后，用去离子水冲洗3次，在60℃干燥10h后得到自源生长的整体式绣球花状羟基氧化钴纳米球催化剂，记为样品5。
实施例6
(1)将1500mg硫脲粉末置于管式炉的刚玉舟里，密封后在30℃下于100mL/min氮气气氛中干燥5h，去除所含水分。
(2)将300mg钴泡沫浸没于无水乙醇中超声清洗10min，然后再60℃下干燥4h。
(3)将步骤(1)得到的干燥硫脲粉末与步骤(2)中得到的钴泡沫共同置于管式炉的刚玉舟里，密封后通入高纯氩气作为全程保护气，其中氩气的流量为40mL/min；以6.5℃/min的速度升温至300℃，保温1h后，自然冷却至室温，得到前驱体。其中，硫脲粉末与钴泡沫质量比为3：1。
(4)将步骤(3)得到的前驱体作为阳极，石墨棒作为阴极，汞/氧化汞电极作为参比电极，共同组装成三电极电解池，在浓度为1M的氢氧化钾溶液中以循环伏安法在-0.3V vs.RHE～1.4V vs.RHE电压窗口下活化2h后，用去离子水冲洗3次，在60℃干燥8h后得到自源生长的整体式绣球花状羟基氧化钴纳米球催化剂，记为样品6。
实施例7
(1)将1500mg升华硫粉末置于管式炉的刚玉舟里，密封后在30℃下于100mL/min氮气气氛中干燥3h，去除所含水分。
(2)将400mg钴片浸没于无水乙醇中超声清洗10min，然后再60℃下干燥4h。
(3)将步骤(1)得到的干燥升华硫粉末与步骤(2)中得到的钴片共同置于管式炉的刚玉舟里，密封后通入高纯氩气作为全程保护气，其中氩气的流量为80mL/min；以8℃/min的速度升温至400℃，保温0.5h后，自然冷却至室温，得到前驱体。其中，升华硫粉末与钴片质量比为3.8：1。
(4)将步骤(3)得到的前驱体作为阳极，石墨棒作为阴极，汞/氧化汞电极作为参比电极，共同组装成三电极电解池，在浓度为1M的氢氧化钾溶液中以循环伏安法在-0.3V vs.RHE～1.4V vs.RHE电压窗口下活化2h后，用去离子水冲洗3次，在60℃干燥8h后得到自源生长的整体式绣球花状羟基氧化钴纳米球催化剂，记为样品7。
实施例8
(1)将1200mg升华硫粉末置于管式炉的刚玉舟里，密封后在30℃下于100mL/min氮气气氛中干燥4h，去除所含水分。
(2)将400mg钴箔浸没于无水乙醇中超声清洗10min，然后再60℃下干燥4h。
(3)将步骤(1)得到的干燥升华硫粉末与步骤(2)中得到的钴箔共同置于管式炉的刚玉舟里，密封后通入高纯氩气作为全程保护气，其中氩气的流量为50mL/min；以7℃/min的速度升温至350℃，保温1h后，自然冷却至室温，得到前驱体。其中，升华硫粉末与钴箔质量比为3：1。
(4)将步骤(3)得到的前驱体作为阳极，石墨棒作为阴极，汞/氧化汞电极作为参比电极，共同组装成三电极电解池，在浓度为1M的氢氧化钾溶液中以恒电流的方式通入5mA/cm 2的电流密度活化至电势稳定并保持10min后，用去离子水冲洗2次，在50℃干燥12h后得到自源生长的整体式绣球花状羟基氧化钴纳米球催化剂，记为样 品8。
实施例9
(1)将1500mg升华硫粉末置于管式炉的刚玉舟里，密封后在30℃下于100mL/min氮气气氛中干燥3h，去除所含水分。
(2)将500mg钴片浸没于无水乙醇中超声清洗10min，然后再60℃下干燥4h。
(3)将步骤(1)得到的干燥升华硫粉末与步骤(2)中得到的钴片共同置于管式炉的刚玉舟里，密封后通入高纯氩气作为全程保护气，其中氩气的流量为60mL/min；以5℃/min的速度升温至380℃，保温1h后，自然冷却至室温，得到前驱体。其中，升华硫粉末与钴片质量比为3：1。
(4)将步骤(3)得到的前驱体作为阳极，石墨棒作为阴极，汞/氧化汞电极作为参比电极，共同组装成三电极电解池，在浓度为1M的氢氧化钾溶液中以计时电位法在1.4V(相对于可逆氢电极)电压窗口下活化60min后，用去离子水冲洗3次，在40℃干燥12h后得到自源生长的整体式绣球花状羟基氧化钴纳米球催化剂，记为样品9。
实施例10
将样品1～样品9进行SEM、EDX和TEM测试。
图1为样品1的扫描电镜图，从图中可以看出，催化剂的微观结构为绣球花状纳米球，且纳米球表面由纳米片组装的三维结构构成，有良好的机械性能。
图2为样品1的EDX测试的元素分布图，从图中可知，钴元素、氧元素均匀分布。
图3为样品1的透射电镜图，从图中可以看出，催化剂的纳米球表面由纳米片组装的三维结构构成，表征结果与扫描电镜图结果一致。
图4为样品1的选区电子衍射图，图中电子衍射环分别对应羟基氧化钴标准卡片26-0480的(0 0 2)、(2 4 0)、(1 4 0)、(0 2 1)面，证明催化剂物相为羟基氧化钴。
样品2～样品9的SEM图、元素分布图、TEM图与样品1相似，仅有纳米球数量与纳米球大小的区别。
样品2～样品9的选区电子衍射图与样品1一致，证明催化剂物相均为羟基氧化钴。
实施例11
工作电极制备：分别将样品1～样品9和纯钴泡沫通过不锈钢电极夹固定制备成工作电极。
对电极：将石墨棒作为对电极。
三电极电解池：工作电极作为阳极，对电极作为阴极，汞/氧化汞电极作为参比电极，固定在聚四氟乙烯塞中，并固定在10mL反应池上。
两电极对称电解池：阴极和阳极是两个相同的工作电极，反应器体积10mL以上。
在常温、常压条件下，利用组装的两电极体系，控制电解池电压为1.7V，分别以氢氧化钾(1M)溶液、10mM BHMF的氢氧化钾(1M)溶液，进行电催化性能测试。
测试装置如图7所示，构建了包括电源1、电解液4、阳极2、阴极3和电流回路的电解池，电解液置于封闭的反应器中，阴极产生的气体通过导气管5导入气体收集装置，并用排水法获取气体体积。气体收集装置包括量筒6，量筒6充满水并倒立在盛有水8的水槽7中，导气管出口位于量筒6内。电解液为10mM BHMF的氢氧化钾(1M)溶液时，仅需较低电压即可驱动该耦合反应。
分别以样品1～样品9为阳极催化剂，进行电催化氧化2,5-呋喃二甲醇(BHMF)制备2,5-呋喃二甲酸(FDCA)测试，各样品催化效果相似，均具有良好的催化效果。典型的以样品1为例，进行说明。
采用样品1作为阳极催化剂，测试结果如图8至图11所示。
图8表明，三电极体系中，自源生长的整体式绣球花状羟基氧化钴纳米球催化剂作为阳极催化剂，比纯泡沫钴作为阳极的电解水析氧性能更好(即达到相同电流密度所需电压更低，曲线更靠近Y轴)， 用于电催化氧化2,5-呋喃二甲醇(BHMF)制备2,5-呋喃二甲酸(FDCA)，较低电压即可驱动反应，性能优越。
图9表明，三电极体系中，自源生长的整体式绣球花状羟基氧化钴纳米球催化剂同时还具有远优于纯泡沫钴作为阴极的电解水产氢的能力(即达到相同电流密度所需电压更低，曲线更靠近Y轴)，电解液中添加10mM BHMF，对其产氢性能并无明显影响(曲线无明显偏移，基本重合)，说明催化剂具有高析氢反应选择性。
采用实施例1制备的样品绣球花状羟基氧化钴纳米球催化剂同时作为阴极催化剂和阳极催化剂组装成两电极对称电解池，分别在无BHMF电解液和10mM BHMF的电解液中进行电催化反应，结果如图10所示，同时进行电催化氧化BHMF制备FDCA、电解水产氢，所需过电位比其单纯分解水低279mV(曲线更靠近Y轴)，表明仅需较低能量即可将BHMF氧化生成FDCA和将水还原为氢气，说明本申请催化剂具有更加优异的催化性能。
采用实施例1制备的样品绣球花状羟基氧化钴纳米球催化剂同时作为阴极催化剂和阳极催化剂组装成两电极对称电解池，电催化氧化BHMF制备FDCA，结果如图11所示，阳极产物包括HMF、FDCA、HMFCA、FFCA和DFF，相对于FDCA，反应终点处HMF、HMFCA、FFCA和DFF的浓度极低，说明催化剂对于FDCA具有很高的选择性，高的FDCA选择性不仅保证了产物的高纯度，而且使得产物的产率非常高。同时，FDCA法拉第效率接近100％，能量利用率高，几乎无能量浪费。
其它样品作为阳极催化剂，均能达到相似的催化效果。
以上所述，仅是本申请的几个实施例，并非对本申请做任何形式的限制，虽然本申请以较佳实施例揭示如上，然而并非用以限制本申请，任何熟悉本专业的技术人员，在不脱离本申请技术方案的范围内，利用上述揭示的技术内容做出些许的变动或修饰均等同于等效实施案例，均属于技术方案范围内。

Claims (13)

  1. 一种钴催化剂，其特征在于，所述钴催化剂包括载体和催化活性物质；
    所述载体为钴基基底材料；
    所述催化活性物质生长于所述载体表面；
    所述催化活性物质的形貌为绣球花状纳米球。
  2. 根据权利要求1所述的钴催化剂，其特征在于，所述催化活性材料以载体为钴源、自源生长在所述载体表面。
  3. 根据权利要求1所述的钴催化剂，其特征在于，所述钴基基底材料选自钴泡沫、钴片、钴箔、钴丝中的至少一种。
  4. 根据权利要求1所述的钴催化剂，其特征在于，所述纳米球直径为100～500nm。
  5. 根据权利要求1所述的钴催化剂，其特征在于，所述纳米球表面片层厚度为1～10nm。
  6. 根据权利要求1-5任一项所述的钴催化剂，其特征在于，所述催化活性物质为羟基氧化钴。
  7. 权利要求1-6任一项所述的钴催化剂的制备方法，其特征在于，所述方法至少包括：
    S100、将载体和硫源在保护气体气氛中，加热反应，得到前驱体；
    S200、将所述前驱体在电解液中，电活化，得到所述钴催化剂。
  8. 根据权利要求7所述的制备方法，其特征在于，在步骤S100中，所述硫源与所述载体的质量比为2～10:1；
    优选地，硫源为升华硫、硫化钠和硫脲中的至少一种。
  9. 根据权利要求7所述的制备方法，其特征在于，在步骤S100中，所述加热反应的温度为300℃～400℃，反应时间为0.25h～2h；
    优选地，所述加热反应的升温速率为5℃/min～10℃/min；
    优选地，所述保护气体的流量为10mL/min～100mL/min。
  10. 根据权利要求7所述的制备方法，其特征在于，所述步骤S200为：
    将所述前驱体作为阳极，在电解液中电活化，洗涤、干燥后，得到所述钴催化剂。
  11. 根据权利要求10所述的制备方法，其特征在于，所述电解液为氢氧化钾溶液、氢氧化钠溶液中的至少一种；
    所述电解液的浓度为0.01M～1M。
  12. 根据权利要求10所述的制备方法，其特征在于，所述电活化方法为循环伏安法、线性伏安法、恒电流法、计时电位法中的任意一种；
    优选地，所述循环伏安法或线性伏安法电活化的条件为：-0.3V vs.RHE～1.4V vs.RHE电压窗口下，活化0.5h～4h；
    优选地，所述恒电流法电活化的条件为：设定电流密度为0.1～100mA/cm 2，通入恒电流活化至电势稳定，活化1～60min；
    优选地，所述计时电位法电活化的条件为：在1～1.6V电位范围内，保持通入电流，并保持1～60min。
  13. 根据权利要求10所述的制备方法，其特征在于，所述干燥条件为：40℃～60℃下干燥6h～12h。
PCT/CN2020/082418 2020-03-31 2020-03-31 一种钴催化剂及其制备方法 WO2021195957A1 (zh)

Priority Applications (3)

Application Number Priority Date Filing Date Title
US17/915,495 US20230220572A1 (en) 2020-03-31 2020-03-31 Cobalt catalyst and preparation method thereof
PCT/CN2020/082418 WO2021195957A1 (zh) 2020-03-31 2020-03-31 一种钴催化剂及其制备方法
EP20929417.2A EP4129469A4 (en) 2020-03-31 2020-03-31 COBALT-BASED CATALYST AND METHOD FOR PREPARING IT

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2020/082418 WO2021195957A1 (zh) 2020-03-31 2020-03-31 一种钴催化剂及其制备方法

Publications (1)

Publication Number Publication Date
WO2021195957A1 true WO2021195957A1 (zh) 2021-10-07

Family

ID=77928166

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2020/082418 WO2021195957A1 (zh) 2020-03-31 2020-03-31 一种钴催化剂及其制备方法

Country Status (3)

Country Link
US (1) US20230220572A1 (zh)
EP (1) EP4129469A4 (zh)
WO (1) WO2021195957A1 (zh)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114232028A (zh) * 2021-12-21 2022-03-25 华东理工大学 一种钴基多层空心异质结电解水催化剂的制备方法

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4846280B2 (ja) * 2005-06-23 2011-12-28 株式会社田中化学研究所 オキシ水酸化コバルト粒子及びその製造方法
CN102712493A (zh) * 2009-08-27 2012-10-03 康宁股份有限公司 氧化锌和氧化钴纳米结构及其制备方法
US20150284259A1 (en) * 2014-04-04 2015-10-08 Samsung Sdi Co., Ltd. Composite precursor of cathode active material, cathode active material, cathode and lithium battery containing the cathode active material, and method of preparing composite precursor
CN108889314A (zh) * 2018-08-08 2018-11-27 湖南理工学院 一种泡沫钴原位硫化纳米花球状Co4S3@Co析氢材料及制备方法

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4846280B2 (ja) * 2005-06-23 2011-12-28 株式会社田中化学研究所 オキシ水酸化コバルト粒子及びその製造方法
CN102712493A (zh) * 2009-08-27 2012-10-03 康宁股份有限公司 氧化锌和氧化钴纳米结构及其制备方法
US20150284259A1 (en) * 2014-04-04 2015-10-08 Samsung Sdi Co., Ltd. Composite precursor of cathode active material, cathode active material, cathode and lithium battery containing the cathode active material, and method of preparing composite precursor
CN108889314A (zh) * 2018-08-08 2018-11-27 湖南理工学院 一种泡沫钴原位硫化纳米花球状Co4S3@Co析氢材料及制备方法

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP4129469A4 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114232028A (zh) * 2021-12-21 2022-03-25 华东理工大学 一种钴基多层空心异质结电解水催化剂的制备方法
CN114232028B (zh) * 2021-12-21 2024-03-29 华东理工大学 一种钴基多层空心异质结电解水催化剂的制备方法

Also Published As

Publication number Publication date
EP4129469A4 (en) 2023-05-17
US20230220572A1 (en) 2023-07-13
EP4129469A1 (en) 2023-02-08

Similar Documents

Publication Publication Date Title
Liu et al. Amorphous Ni (OH) 2 encounter with crystalline CuS in hollow spheres: a mesoporous nano-shelled heterostructure for hydrogen evolution electrocatalysis
Wang et al. Nanostructured amorphous Fe29Co27Ni23Si9B12 high-entropy-alloy: an efficient electrocatalyst for oxygen evolution reaction
Zhu et al. Hydrophilic cobalt sulfide nanosheets as a bifunctional catalyst for oxygen and hydrogen evolution in electrolysis of alkaline aqueous solution
Aftab et al. Mixed CoS2@ Co3O4 composite material: An efficient nonprecious electrocatalyst for hydrogen evolution reaction
WO2021051897A1 (zh) 一种电催化5-羟甲基糠醛氧化制备2,5-呋喃二甲酸同时电解水制氢气的方法
CN109908938A (zh) 一种新型电解水阳极析氧催化剂Co@NC/CNT的制备方法
JP2002512429A (ja) 硫化水素の電気化学的気相酸化法
Ding et al. Mixed Ni–Cu-oxide nanowire array on conductive substrate and its application as enzyme-free glucose sensor
Jin et al. Hierarchical NiCo2O4 and NiCo2S4 nanomaterials as electrocatalysts for methanol oxidation reaction
CN110205636A (zh) 一种自支撑型三维多孔结构双功能催化电极的制备方法
CN110838588A (zh) 一种可充式锌空电池双功能催化剂及其制备方法与应用
Yu et al. Prompt electrodeposition of Ni nanodots on Ni foam to construct a high-performance water-splitting electrode: efficient, scalable, and recyclable
CN112962108B (zh) 锌离子电池的再生电极在二氧化碳电化学还原中的应用
Yan et al. Hierarchical cobalt phosphide hollow nanoboxes as high performance bifunctional electrocatalysts for overall water splitting
Li et al. Graphene supported atomic Co/nanocrystalline Co3O4 for oxygen evolution reaction
CN113457679A (zh) 一种羟基氧化钴催化剂制备方法和应用
Chanda et al. Hydrothermally/electrochemically decorated FeSe on Ni-foam electrode: An efficient bifunctional electrocatalysts for overall water splitting in an alkaline medium
CN107833758A (zh) 一种镍基一体化电极的制备方法、产品及应用
CN111215096A (zh) 一种负载四硫化二钴镍纳米片的石墨烯复合材料的制备及应用
CN111483999A (zh) 一种氮掺杂碳纳米管的制备方法、氮掺杂碳纳米管及其应用
CN109837559A (zh) 一种水热辅助的羟基氧化铁-镍铁水滑石一体化电极的制备方法
Shen et al. Highly active bifunctional catalyst: Constructing FeWO4-WO3 heterostructure for water and hydrazine oxidation at large current density
Dong et al. Selective phosphidation and reduction strategy to construct heterostructured porous nanorod of CoP coated on Mn3O4 as a bifunctional electrocatalyst for overall water splitting
CN109621969A (zh) 一种自支撑双金属镍钨碳化物全解水材料及其制备方法
Liu et al. Valence regulation of Ru/Mo2C heterojunction for efficient acidic overall water splitting

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 20929417

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

ENP Entry into the national phase

Ref document number: 2020929417

Country of ref document: EP

Effective date: 20221028