Reduced-graphene-oxide-supported Ni@Pd core-shell-structure electrocatalyst and preparation method thereof

A technology of electrocatalyst and core-shell structure, applied in the field of electrocatalyst and its preparation, can solve the problems of large amount of precious metals, improved catalyst stability and activity, etc., and achieve the effects of mild experimental conditions, improved activity and stability, and easy realization.

Inactive Publication Date: 2017-06-23
BEIJING INSTITUTE OF TECHNOLOGYGY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to solve the problems in the prior art that the amount of precious metals is large and the catalyst stability and act

Method used

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  • Reduced-graphene-oxide-supported Ni@Pd core-shell-structure electrocatalyst and preparation method thereof
  • Reduced-graphene-oxide-supported Ni@Pd core-shell-structure electrocatalyst and preparation method thereof
  • Reduced-graphene-oxide-supported Ni@Pd core-shell-structure electrocatalyst and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0030] An electrocatalyst with a core-shell structure of Ni@Pd with reduced graphene oxide as a carrier, using reduced graphene oxide as a carrier, assembled on the surface of non-noble metal Ni with a thin-shell precious metal Pd to prepare uniformly dispersed in reduced graphene oxide (rGO) Electrocatalyst Ni@Pd with core-shell structure.

[0031] The mass fraction of Ni in this embodiment is 20% of the obtained electrocatalyst; namely:

[0032] m Ni %=m Ni / (m rGO +m Ni +m Pd )=14.3 / (50+14.3+7.2)=20%

[0033] The mass fraction of Pd in ​​this embodiment is 10% of the obtained electrocatalyst; namely:

[0034] m Pd %=m Pd / (m rGO +m Ni +m Pd )=7.2 / (50+14.3+7.2)=10%

[0035] The Ni precursor used in this example is NiCl 2 ·6H 2 O, the reducing agent is NaBH 4 .

[0036] A preparation method of Ni@Pd core-shell structure electrocatalyst with reduced graphene oxide as a carrier, the specific steps are as follows:

[0037] Step 1. Use Hummers method to prepare graphene oxide ...

Embodiment 2

[0041] 1) Prepare 500 ml of 2.0 mol / L potassium hydroxide solution, and prepare 500 ml of 2.0 mol / L potassium hydroxide and 1.0 mol / L ethanol solution.

[0042] 2) Using 985 μl of ethanol as a solvent and 15 μl of Nafion solution as a binder, 2 mg of Ni@Pd-rGO catalyst was prepared into a 2 mg / ml dispersion, and dispersed by ultrasound.

[0043] 3) Take 10μl of the dispersed liquid drop on the rotating disk electrode (the area of ​​the disk is 0.25cm 2 ), in the 2.0mol / L potassium hydroxide solution, N 2 After purging for 30 min, cyclic voltammetry (CV) was performed. After the CV curve is stable, the solution is replaced with 2.0mol / L potassium hydroxide and 1.0mol / L ethanol solution, N 2 After purging for 30 minutes, the catalytic performance of Ni@Pd-rGO catalyst for ethanol oxidation (EOR) was measured by cyclic linear voltammetry, and the scanning range was -0.9-0.2V vs.Hg / HgO. From image 3 It can be seen that the starting point of Ni@Pd-rGO, a nanoparticle catalyst with a co...

Embodiment 3

[0045] 1) Using n-propanol as a solvent, disperse the non-noble metal catalyst with a mass fraction of 3.5% (the ratio of catalyst to ionomer is 7:3), and ultrasonically disperse. Spray the dispersion evenly on the carbon paper as the cathode of DEFC.

[0046] 2) Using n-propanol as the solvent, dispersing the core-shell structure nanoparticle catalyst Ni@Pd-rGO, using 5% polytetrafluoroethylene (PTFE) as the binder (the mass ratio of Ni@Pd-rGO to PTFE is 9:1), ultrasonic dispersion. Spray the dispersion evenly on the carbon cloth with a mass fraction of 0.5mgPd / cm 2 , As the anode of DEFC.

[0047] 3) Assemble the graphite flow field plate, anode carbon cloth, proton exchange membrane, and cathode carbon paper into a DEFC battery, and connect it with a fuel cell test system (Arbin BT2000) to test the performance of the DEFC battery. The anode fuel is 6.0 mol / L potassium hydroxide and 3.0 mol / L ethanol solution, and the cathode gas is oxygen. DEFC was tested for voltage and curr...

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Abstract

The invention relates to a reduced-graphene-oxide-supported Ni@Pd core-shell-structure electrocatalyst and a preparation method thereof, belonging to the field of composite materials. The method comprises the following steps: preparing graphene oxide by a Hummers process; preparing a mixed solution from NiCl2 and GO, and reducing Ni<2+> by using NaBH4 to obtain a Ni simple substance and reduced graphene oxide (rGO); adding a H2PdCl4 solution, and carrying out Ni-Pd<2+> replacement reaction to obtain Pd; and coating the Pd onto the Ni surface to form a Ni@Pd core-shell structure, and supporting the Ni@Pd core-shell structure onto the rGO. The preparation method is simple in steps, and fully utilizes the raw materials. The product has the obvious and unique core-shell structure shape characteristics, and has favorable catalytic properties for ethanol oxidation and oxygen reduction reaction. When being directly used in ethanol fuel cell anode catalysis and cathode oxygen reduction reaction, the electrocatalyst has wide application prospects.

Description

Technical field [0001] The invention relates to an electrocatalyst with a core-shell structure of Ni@Pd with reduced graphene oxide as a carrier and a preparation method thereof, belonging to the field of composite materials. Background technique [0002] Noble metal (such as Pt-based, Pd-based, etc.) nanoparticles are highly efficient electrocatalysts, which are widely used in DEFC anode catalysis and oxygen reduction reactions (ORR). Pd-based catalysts are used as electrocatalysts in alkaline media. , Its preparation methods mainly include: immersion reduction method, colloid method, electrodeposition and chemical displacement reaction. Studies have shown that Pd is expensive and the catalyst cost is high, which is a key factor hindering its wide application, and the stability and activity of Pd-based catalysts still need to be improved. One of the effective ways to reduce the amount of noble metal and improve the catalytic activity is to prepare binary metal core-shell nanopa...

Claims

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Application Information

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IPC IPC(8): B01J23/89H01M4/90
CPCB01J23/892B01J35/0033B01J35/0073H01M4/9041H01M4/9083Y02E60/50
Inventor 孙克宁王芳王珺乔金硕
Owner BEIJING INSTITUTE OF TECHNOLOGYGY
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