Fe/Co/N/MWCNTs catalyst

A catalyst, fecl3 6h2o technology, applied in electrical components, battery electrodes, circuits, etc., can solve the problems of low current density, low ORR initial potential, and reduced catalytic activity, achieving good thermal stability and good catalytic activity stability performance, excellent electrocatalytic activity

Inactive Publication Date: 2018-05-29
韩会义
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, in general, this type of C-N catalyst containing Fe or Co has a low onset potential for ORR and a low current density, an

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment example 1

[0011] Fe / Co / N / MWCNTs catalyst preparation raw materials include: sodium hydroxide, concentrated sulfuric acid, concentrated hydrochloric acid (36%-38%), FeCl 3 ·6H 2 O, CO (NO 3 ) 2 ·6H 2 O, aniline, ammonium persulfate, absolute ethanol (analytically pure), ethylenediamine (analytical pure), Nafion solution (5% by mass fraction), etc.; water is deionized water and purified water through secondary distillation; The multi-walled carbon nanotubes were soaked in concentrated hydrochloric acid for 24 hours to remove possible metal impurities. After filtering, they were washed repeatedly with pure water until neutral, and dried for later use. The preparation steps of Fe / Co / N / MWCNTs catalyst are as follows: add 2ml aniline, 0.5mol·L -1 HCl solution 10ml and appropriate amount of ammonium persulfate solid, then add 0.34g FeCl 3 ·6H 2 O solid, stir well to make Fe - Cl 3 ·6H 2 O solid is completely dissolved. Then the mixture was reacted in an environment below 10°C for 24h...

Embodiment example 2

[0013] The electrochemical test was carried out in a traditional three-electrode system, in which the auxiliary electrode was a platinum electrode, the reference electrode was a saturated calomel electrode, the working electrode was connected to a rotating disk electrode, and the electrolyte solution was 0.5mol L -1 H 2 SO 4 Solution or 1mol·L -1 NaOH solution: from the catalyst at 0.5mol L -1 h 2 SO 4 The cyclic voltammogram in the solution shows that the catalysts treated at different temperatures are in O 2 An obvious reduction peak appeared at 0.2V in the saturated solution, indicating that the catalyst has strong catalytic activity for oxygen reduction. In addition, no matter in the solution full of N2 or full of O2, the current density of the oxidation process and the reduction process on the CV diagram gradually increase with the increase of the heating temperature, and the current density reaches the maximum at 500 ° C. The current density begins to decrease at 6...

Embodiment example 3

[0015] Adopt AutolabPGSTAT30 (Netherlands) to test the electrochemical performance of catalyst:

[0016] Determination of polarization curves at different rotational speeds with ATA-IB rotating disk electrode: 0.5mol L -1 H 2 SO 4 In the solution, the catalyst FeN has the least activity for ORR, the ORR onset potential is about 0.15V (vsSCE), and its current density is the lowest; when FeCoNC is heat-treated at different temperatures, the electrical activity for ORR increases significantly. When the heating temperature increased from 200 °C to 500 °C, the onset potential of the catalyst for ORR was shifted continuously, and the current density was also increased, but the activity of ORR decreased when the degree of ORR was further increased. When the heating temperature is 500°C, the initial ORR potential of the catalyst is about 0.63V (vsSCE), and then the electric density increases rapidly. The density is the highest, reaching 7mA cm-2@-0.3V (vsSCE). From the catalyst at 1...

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PUM

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Abstract

A Fe/Co/N/MWCNTs catalyst is obtained as follows: an iron-ion-doped polyaniline (PANI) and carbon nanotube (MWCNT) compound is heated at 900DEG C to obtain an iron-containing catalyst FeNC; and the FeNC containing a cobalt salt is calcined at different temperatures to obtain the composite catalyst FeCoNC. With the increase of calcination temperature, the surface structure of the catalyst tends tobe uniform. The surface structure of the catalyst with the calcination temperature of 500DEG C is most even and smooth, and sintering occurs when the temperature is above 500DEG C. A higher nitrogen content can improve the ORR electroactivity of the catalyst. The catalyst with the calcination temperature of 500 DEG C has highest ORR electrocatalytic activity. ORR initial potentials in acidic and alkaline solutions are 0.63 and-0.12V (vsSCE), respectively, current densities are 11.67 and 9. 83mAmg-1@-0.3V(vsSCE) respectively, and the catalyst has good thermal stability and catalytic activity stability. The catalyst obtained by stepwise adding Fe and Co and calcining at 500 DEG C after addition of the Co has excellent ORR electrocatalytic activity.

Description

technical field [0001] The invention relates to a catalyst, in particular to a Fe / Co / N / MWCNTs catalyst. Background technique [0002] Fuel cells are one of the alternative power sources for portable electronic devices due to their high efficiency, low pollution and fast start-up. Catalysts used in the cathode reaction (ORR) of fuel cells are mostly Pt and Pt-based metals. Pt is expensive, and the diffusion of methanol to the cathode catalyst is easy to poison it. Therefore, it is of great significance to develop new ORR catalysts based on non-noble metals. [0003] Since Jasinski discovered the electroactivity of nitrogen-containing metal macrocycles for oxygen reduction, the catalytic activity of transition metal macrocycles for oxygen reduction has become a research hotspot. The catalytic active sites of such catalysts mainly come from TM-N4 fragments, or C-N structural units. However, this transition metal macrocycle catalyst has poor stability in acidic environment, ...

Claims

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Application Information

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IPC IPC(8): H01M4/90H01M4/88
CPCH01M4/8825H01M4/9041H01M4/9091Y02E60/50
Inventor 韩会义
Owner 韩会义
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