阅读说明：本技术 一种Pt/Ni3N@Mo2C氢氧化氢析出电催化剂制备方法 (Pt/Ni alloy3N@Mo2Preparation method of C hydrogen hydroxide evolution electrocatalyst ) 是由 杨秀林 杨玉婷 刘奕 于 2021-09-02 设计创作，主要内容包括：本发明涉及碱性交换膜燃料电池以及电催化水分解技术领域,具体为一种Pt/Ni-(3)N@Mo-(2)C氢氧化氢析出电催化剂的制备方法,本发明通过合成Mo-PDA前驱体,将所述Mo-PDA前驱体在氩气气氛下进行高温碳化处理得到Mo-(2)C。所述氮化是将合成的Ni(OH)-(2)与Mo-(2)C混合氮化得到Ni-(3)N@Mo-(2)C,所述湿化学是通过在室温下利用氢气在溶液中将Pt簇还原到Ni-(3)N@Mo-(2)C。本发明制备方法简单,Pt/Ni-(3)N@Mo-(2)C复合材料在碱性条件下具有优异的电催化氢氧化氢析出性能,且优于商业Pt/C催化剂。其作为锌-水电池的阴极催化剂时,展现了良好的稳定性和较高的功率密度,证实了本发明制备的Pt/Ni-(3)N@Mo-(2)C复合材料在锌-水电池方面具有良好的应用前景。(The invention relates to the technical field of alkaline exchange membrane fuel cells and electrocatalytic water decomposition, in particular to Pt/Ni 3 N@Mo 2 The invention relates to a preparation method of an electrocatalyst for separating out hydrogen hydroxide C, which comprises the steps of synthesizing a Mo-PDA precursor, and carrying out high-temperature carbonization treatment on the Mo-PDA precursor in an argon atmosphere to obtain Mo 2 C. The nitridation is to synthesize Ni (OH) 2 And Mo 2 Mixed nitridation of C to obtain Ni 3 N@Mo 2 C, the wet chemistry is to reduce Pt clusters to Ni in solution with hydrogen at room temperature 3 N@Mo 2 C. The preparation method is simple, and the Pt/Ni 3 N@Mo 2 C composite material in alkalineHas excellent electrocatalytic hydrogen hydroxide evolution performance under the condition and is superior to a commercial Pt/C catalyst. When the catalyst is used as a cathode catalyst of a zinc-water battery, good stability and higher power density are shown, and the Pt/Ni prepared by the method is proved 3 N@Mo 2 The C composite material has good application prospect in the aspect of zinc-water batteries.)

1. Pt/Ni alloy₃[email protected]₂The preparation method of the electrocatalyst for hydrogen hydroxide precipitation is characterized by comprising the following steps: comprises the steps of preparing a Mo-PDA precursor by a stirring method at room temperature, and carbonizing the precursor in an argon atmosphere to obtain Mo₂C, preparation of Ni (OH) by hydrothermal method₂Mixing said Ni (OH)₂And said Mo₂Mixing C and nitriding to obtain Ni₃[email protected]₂C, a composite carrier; then reducing Pt cluster loaded on the Ni at room temperature by using a wet chemical method₃[email protected]₂On a C composite carrier to obtain Pt/Ni₃[email protected]₂And C, a composite material.

2. The method of claim 1, wherein: the preparation method of the Mo-PDA precursor comprises the steps of ultrasonically dissolving ammonium molybdate in a mixed solution of ethanol and deionized water, and then dropwise adding ammonia water to adjust the pH value to 7-8 to form a solution A; dissolving dopamine hydrochloride in a mixed solution of deionized water to form a solution B, dropwise adding the solution B into the solution A, stirring at room temperature for 12 hours, and centrifugally drying to obtain the Mo-PDA precursor.

3. The method of claim 2, wherein: the carbonization treatment is to heat to 850 ℃ under the argon atmosphere, keep for 3 hours, and then naturally cool to room temperature.

4. The production method according to claim 3, characterized in that: the temperature of the hydrothermal reaction is 100 ℃, the reaction time is 4 h, and the Ni (OH) is obtained₂。

5. The method of claim 4, wherein: the nitriding treatment is carried out by reacting the Ni (OH)₂And said Mo₂C was mixed in an acetone solution, stirred for 4 h, acetone was removed by a rotary evaporator, and then calcined at 370 ℃ for 3 h in an ammonia atmosphere.

6. The method of claim 5, wherein: the wet chemical method is to mix the Ni₃[email protected]₂And dispersing the C composite carrier into a mixed solution of deionized water and hydrochloric acid, reducing potassium chloroplatinate at room temperature in a hydrogen atmosphere, standing at room temperature, centrifuging and drying.

Technical Field

The invention belongs to alkalinityAn exchange membrane fuel cell and the field of electrocatalytic water decomposition, in particular to Pt/Ni₃[email protected]₂C, preparing the electrocatalyst for hydrogen hydroxide precipitation.

Background

The water electrolyzer and the fuel cell play a vital role in sustainable energy conversion, can slow down global warming and reduce the use of traditional fossil fuels. Hydrogen (H)₂) Is considered an attractive clean energy carrier, which can be obtained by water splitting, and water is the only product in the hydrogen oxidation process. In fact, the oxidation reaction of Hydrogen (HOR) and the evolution reaction of Hydrogen (HER) are key determinants of the energy efficiency of these devices, since they operate in reversible fuel cells, including fuel cell mode and electrolysis mode. However, the slow alkaline hydrogen oxidation reaction hinders the development of fuel cells. In order to solve the above problems, the development of a high-performance basic medium hydrogen oxidation/hydrogen evolution electrocatalyst is urgently required.

Disclosure of Invention

The invention aims to provide Pt/Ni₃[email protected]₂A preparation method of an electrocatalyst for hydrogen hydroxide precipitation, which solves the problems in the background technology.

In order to achieve the purpose, the invention provides the following technical scheme:

Pt/Ni alloy₃[email protected]₂The preparation method of the C hydrogen hydroxide evolution electrocatalyst comprises the steps of preparing a Mo-PDA precursor by a stirring method at room temperature, and carbonizing the precursor in an argon atmosphere to obtain Mo₂C, preparation of Ni (OH) by hydrothermal method₂Mixing said Ni (OH)₂And said Mo₂Mixing C and nitriding to obtain Ni₃[email protected]₂C, a composite carrier; then reducing Pt cluster loaded on the Ni at room temperature by using a wet chemical method₃[email protected]₂On a C composite carrier to obtain Pt/Ni₃[email protected]₂And C, a composite material.

Further, preparing the Mo-PDA precursor by ultrasonically dissolving ammonium molybdate in a mixed solution of ethanol and deionized water, and then dropwise adding ammonia water to adjust the pH value to 7-8 to form a solution A; dissolving dopamine hydrochloride in a mixed solution of deionized water to form a solution B, dropwise adding the solution B into the solution A, stirring at room temperature for 12 hours, and centrifugally drying to obtain the Mo-PDA precursor.

Further, the carbonization treatment is carried out by heating to 850 ℃ under an argon atmosphere, holding for 3 hours, and then naturally cooling to room temperature.

Further, the temperature of the hydrothermal reaction is 100 ℃, the reaction time is 4 h, and the Ni (OH) is obtained₂。

Further, the nitriding treatment is to mix the Ni (OH)₂And said Mo₂C was mixed in an acetone solution, stirred for 4 h, acetone was removed by a rotary evaporator, and then calcined at 370 ℃ for 3 h in an ammonia atmosphere.

Further, the wet chemical method is to mix the Ni₃[email protected]₂And dispersing the C composite carrier into a mixed solution of deionized water and hydrochloric acid, reducing potassium chloroplatinate at room temperature in a hydrogen atmosphere, standing at room temperature, centrifuging and drying.

Compared with the prior art, the invention has the beneficial effects that:

the preparation method is simple, and Pt/Ni is obtained by self-assembly, nitridation and wet chemistry methods₃[email protected]₂The C composite material has excellent electro-catalytic hydrogen hydroxide precipitation performance under the alkaline condition, shows good long-term stability and higher power density when being used as an air cathode catalyst of a zinc-water battery, and confirms that the Pt/Ni prepared by the invention₃[email protected]₂The C composite material has good application prospect in the aspect of zinc-water batteries.

Drawings

FIG. 1 Pt/Ni prepared according to example 4 of the present invention₃[email protected]₂An X-ray powder diffraction pattern of C;

FIG. 2 shows Mo (a) in example 4 of the present invention₂C precursor, (b) Ni₃[email protected]₂C composite precursor and (C) Pt/Ni₃[email protected]₂Scanning electron microscope picture of C composite material, (d) transmission electron microscope picture, (e) transmission electron microscope picture and particle sizeThe distribution picture, (f) the high-resolution transmission electron microscope picture, (g) the high-angle annular dark field transmission electron microscope picture and all elements are uniformly distributed in the composite material;

FIG. 3 shows Pt/Ni prepared in example 4 of the present invention₃[email protected]₂C, preparing an X-ray photoelectron energy spectrum from the composite material;

FIG. 4 shows Pt/Ni prepared by the present invention₃[email protected]₂C composite material, Pt/Mo₂C、Pt/Ni₃N、Ni₃[email protected]₂Electrocatalytic hydrogen oxidation linear scan curves for C and commercial Pt/C under alkaline conditions;

FIG. 5 shows Pt/Ni prepared by the present invention₃[email protected]₂C composite material, Pt/Mo₂C、Pt/Ni₃N、Ni₃[email protected]₂Electrocatalytic hydrogen evolution linear scan curves for C and commercial Pt/C under alkaline conditions;

FIG. 6 (a) shows Pt/Ni prepared by the present invention₃[email protected]₂The polarization curve and the power density curve of the zinc-water battery of the composite material C under the alkaline condition are shown in fig. 6 (b), and the stability of the zinc-water battery of the embodiment 4 of the invention under the alkaline condition is shown.

Detailed Description

The technical solution in the embodiment of the present invention will be described below with reference to fig. 1 to 6 in the embodiment of the present invention.

First, commercial Pt/C was selected as an electrode sample for comparison with the examples of the present invention: weighing 4 mg of commercial Pt/C, ultrasonically dispersing in 495 muL deionized water, 495 muL isopropyl alcohol and 10 muL Nafion solution, ultrasonically treating for 1 hour, and dripping the Pt/C catalyst ink after uniform dispersion on a glassy carbon electrode with the diameter of 5 mm (the loading amount is 30.6 mug cm)²) And drying at room temperature for later use.

II, zinc-water battery cathode catalyst:

commercial Pt/C was prepared as an electrode sample for comparison with the inventive examples: weighing 2 mg of commercial Pt/C, ultrasonically dispersing the Pt/C in 145 muL deionized water, 145 muL isopropyl alcohol and 10 muL Nafion solution, ultrasonically treating for 1 hour, and dripping the uniformly dispersed Pt/C catalyst ink into 1.5 x 2 cm²On carbon paper (loading 2 mg cm)²) And drying at room temperature for later use.

Third, example 1: preparation of Pt/Ni₃N composite material

Preparing a solution in step (1): 6 mmol of nickel nitrate hexahydrate, 12 mmol of ammonium fluoride and 30 mmol of urea are weighed, dissolved in 70 mL of deionized water by ultrasonic waves, and stirred for 30 min.

Step (2) hydrothermal reaction: transferring the solution obtained in the step (1) into a 90 mL reaction kettle, and keeping the temperature in an oven at 100 ℃ for 4 h. After natural cooling, the green powder was washed centrifugally with deionized water and ethanol and dried at 60 ℃ to give Ni (OH)₂And (5) standby.

Step (3), nitriding treatment: weighing 80 mg of the green powder, heating to 370 ℃ in an ammonia atmosphere, keeping for 3 hours, and naturally cooling to room temperature to obtain Ni₃And (3) N material.

Step (4), wet chemical method: weighing 20 mg of Ni₃The N material was dissolved in 50 mL of a mixture of deionized water and 1 mM HCl by sonication to form solution A, and 0.34 mM K was weighed₂PtCl₆The solution B was dissolved in 50 mL of deionized water by sonication. At H₂Slowly dripping the solution B into the solution A under the atmosphere, continuously stirring for 20 min after dripping, standing for 5 h at room temperature, centrifuging, and drying in an oven at 60 ℃ to obtain Pt/Ni₃N composite material.

Fourth, example 2: preparation of Pt/Mo₂C composite material

Preparing a solution in step (1): weighing 0.3 mmol of ammonium molybdate, ultrasonically dissolving the ammonium molybdate in a mixed solution of 18 mL of deionized water and 8mL of absolute ethyl alcohol, and then dropwise adding ammonia water to adjust the pH value to 7-8 to form a solution A; dopamine hydrochloride was dissolved in deionized water to form solution B.

And (2) dropwise adding the solution B into the solution A, stirring for 12 hours at room temperature, and centrifugally drying to obtain a Mo-PDA precursor.

And (3) carbonizing treatment: placing the Mo-PDA precursor in the step (2) in a porcelain boat, heating to 850 ℃ at the speed of 2 ℃/min under the argon atmosphere, keeping for 3 hours, and naturally cooling to room temperature to obtain Mo₂C。

Step (ii) of(4) Wet chemical method: weighing 20 mg of Mo₂C ultrasonic dissolving in 50 mL of a mixture of deionized water and 1 mM HCl to form a solution A, and weighing 0.34 mM K₂PtCl₆The solution B was dissolved in 50 mL of deionized water by sonication. At H₂Slowly dripping the solution B into the solution A under the atmosphere, continuously stirring for 20 min after dripping, standing for 5 h at room temperature, centrifuging, and drying in an oven at 60 ℃ to obtain Pt/Mo₂And C, a composite material.

Fifth, example 3: preparation of Ni₃[email protected]₂C composite material

Preparing a solution in step (1): weighing 40 mg Ni (OH)₂And 100 mg of Mo₂C was dissolved in 40 mL of acetone solution with stirring, and stirring was continued at room temperature for 4 h, after which the acetone was removed by rotary evaporator to give a blue-black powder.

Step (2) nitriding treatment: weighing 80 mg of the bluish black powder, heating to 370 ℃ at 5 ℃/min in an ammonia atmosphere, keeping for 3 hours, and naturally cooling to room temperature to obtain Ni₃[email protected]₂And C, a composite material.

Sixth, example 4: preparation of Pt/Ni₃[email protected]₂C composite material

Preparing a solution in step (1): weighing 20 mg of Ni₃[email protected]₂C ultrasonic dissolving in 50 mL of a mixture of deionized water and 1 mM HCl to form a solution A, and weighing 0.34 mM K₂PtCl₆The solution B was dissolved in 50 mL of deionized water by sonication.

Step (2) wet chemical method: at H₂Slowly dripping the solution B into the solution A under the atmosphere, and continuously stirring for 20 min after dripping. Standing for 5 h at room temperature, centrifuging, and drying in an oven at 60 ℃ to obtain Pt/Ni₃[email protected]₂And C, a composite material.

Electrochemical test

Electrochemical test (1): electrochemical hydrogen oxidation tests were performed on electrochemical workstations (shanghai CHI 760E and U.S. PINE) using a three-electrode system. The catalyst prepared in each example is dropped on a glassy carbon electrode to be used as a working electrode, a carbon rod is used as a counter electrode, a saturated silver-silver chloride electrode is used as a reference electrode, 0.1 mol/L potassium hydroxide solution is used as an electrolyte, the test temperature is 25 ℃, the scanning speed is 10 mV/s, and the scanning range is-1.014 to-0.458V. The electrode potential was obtained for a saturated silver-silver chloride electrode and corrected for a Reversible Hydrogen Electrode (RHE). The hydrogen oxidation potential is obtained according to the following nernst equation:

E_RHE = E_Ag/AgCl+ 0.197 + 0.059pH

electrochemical test (2): electrochemical hydrogen evolution tests were performed on an electrochemical workstation (shanghai CHI 760E and U.S. PINE) using a three-electrode system. The catalyst prepared in each example is dropped on a glassy carbon electrode to be used as a working electrode, a carbon rod is used as a counter electrode, a saturated silver-silver chloride electrode is used as a reference electrode, 1 mol/L potassium hydroxide solution is used as an electrolyte, the test temperature is 25 ℃, the scanning speed is 10 mV/s, and the scanning range is-0.973 to-1.423V. The electrode potential was obtained for a saturated silver-silver chloride electrode and corrected for a Reversible Hydrogen Electrode (RHE). The hydrogen oxidation potential is obtained according to the following nernst equation:

ERHE = EAg/AgCl + 0.197+0.059pH

electrochemical test (3): zinc-water cell testing was performed on an electrochemical workstation (shanghai CHI 760E) and a blue cell testing system (BT 2016A). The Pt/Ni prepared in example 1 was added₃[email protected]₂The C composite material is used as an air cathode of a zinc-water battery, a zinc plate is used as an anode, a mixed solution of 6 mol/L potassium hydroxide and 0.2 mol/L zinc acetate is used as an electrolyte, and the test temperature is 25 ℃. The power density is obtained according to the following equation:

P = UI

sixthly, analysis of test results

FIG. 1 shows that the samples prepared in example 4 each have Mo₂C、 Ni₃Characteristic peaks of typical X-ray powder diffraction of N and Pt. The material is obtained by carbonizing at high temperature, and therefore has a characteristic diffraction peak of 002 surface typical of graphitized carbon.

FIG. 2 (a) Mo₂C precursor, FIG. 2 (b) Ni₃[email protected]₂C composite precursor and FIG. 2 (C) Pt/Ni₃[email protected]₂Scanning electron microscope pictures of the C composite material, it can be seen that the morphology of example 4 is substantially maintained with Mo₂C, the shape of the flower-shaped microspheres is similar; fig. 2 (d) transmission electron microscope picture, fig. 2 (e) transmission electron microscope picture and corresponding particle size distribution picture, fig. 2 (f) high resolution transmission electron microscope picture, fig. 2 (g) high angle annular dark field transmission electron microscope picture and each element is uniformly distributed in the composite material.

FIG. 3 (a) shows the results in Pt/Ni₃[email protected]₂The presence of C, N, Mo, Ni, Pt in the C composite, fig. 3 (C) demonstrates that molybdenum is present in the form of carbide. FIG. 3 (d) demonstrates that nickel is present in the form of nitride, FIG. 3 (e) demonstrates that platinum is present in the form of simple substance, and Ni is 3 in the low wavenumber regionpThe strong interaction of platinum with nickel is demonstrated, thereby increasing the conductivity and intrinsic catalytic activity of the catalyst.

FIG. 4 shows Pt/Ni prepared by the present invention₃[email protected]₂C composite material, Pt/Mo₂C、Pt/Ni₃N、Ni₃[email protected]₂The electrocatalytic hydrogen oxidation linear scanning curves of C and commercial Pt/C under alkaline conditions, compared with other samples, demonstrate that the Pt/Ni prepared by the invention has higher limiting current density₃[email protected]₂C has excellent hydrogen oxidation activity.

FIG. 5 shows Pt/Ni prepared by the present invention₃[email protected]₂C composite material, Pt/Mo₂C、Pt/Ni₃N、Ni₃[email protected]₂Electrocatalytic hydrogen evolution linear scanning curves of C and commercial Pt/C under alkaline condition when the current density reaches 10 mA/cm²The overpotential for hydrogen evolution needs only 11 mV, and has lower overpotential compared with other samples, which confirms that the Pt/Ni prepared by the method has low overpotential₃[email protected]₂C has excellent hydrogen evolution activity.

FIG. 6 (a) shows Pt/Ni₃[email protected]₂The power density of a zinc-water battery assembled by using the C composite material as an air cathode is obviously higher than that of a commercial Pt/C catalyst; FIG. 6 (b) shows that it exhibits good stability as a cathode catalyst for a zinc-water battery, confirming that Pt/Ni prepared according to the present invention₃[email protected]₂C composite in zinc-waterHas good application prospect in the aspect of batteries.

In conclusion, the Pt/Ni is obtained by the methods of self-assembly, nitridation and wet chemistry₃[email protected]₂And C, a composite material. Processing the obtained Pt/Ni₃[email protected]₂A C composite exhibiting electrocatalytic hydrogen oxidation and hydrogen evolution properties comparable to commercial Pt/C under alkaline conditions; when the catalyst is used as a cathode catalyst of a zinc-water battery, good stability and higher power density are shown, and the Pt/Ni prepared by the method is proved₃[email protected]₂The C composite material not only has excellent hydrogen oxidation and hydrogen precipitation performances, but also has good application prospect in the aspect of zinc-water batteries.

While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.