Oxygen reduction catalyst for zinc-air battery and preparation method thereof

Abstract

The invention belongs to the field of chemical power source and electrochemical catalysis, and more specifically relates to an oxygen reduction catalyst for a zinc-air battery and a preparation method thereof. The oxygen reduction catalyst is a supported catalyst, and is composed of nano Ag particles and carbon nanotubes, wherein the mass ratio of nano Ag particles and carbon nanotubes is 1:1 to 1:50, the particle size of nano Ag particles is 10 to 20nm, and the specific surface area of carbon nanotubes is 100 to 500m2 / g. The preparation method comprises following steps: Ag+ of AgNO3 solution is reduced to nano Ag particles by using solution reduction method, carbon nanotube carriers are treated by mixed acid, and then nano Ag particles are loaded on the carbon nanotube carriers. The size distribution of the nano Ag particles is uniform, and the nano Ag particles distribute on the surface of the carbon nanotubes uniformly, so that the oxygen reduction catalyst possesses excellent electrochemical performances, and can be used for oxygen reduction of the cathode of the zinc-air battery; and the oxygen reduction in an alkaline environment is mainly four-electron reaction.

Description

technical field

[0001] The invention relates to the fields of chemical power sources and electrochemical catalysis, in particular to an oxygen reduction catalyst for a zinc-air battery and a preparation method thereof. Background technique

[0002] As a metal fuel cell, zinc-air battery has a high specific energy (its theoretical specific energy is as high as 1350WhKg -1 ), low cost, environmental friendliness, and mechanical replacement (fast charging of zinc-air batteries by replacing fully discharged zinc anodes), etc., have attracted the attention of domestic and foreign researchers in recent years. A zinc-air battery consists of three parts: a zinc metal anode, an alkaline electrolyte, and an air cathode. During battery discharge, zinc dissolution occurs at the zinc anode and oxygen reduction reaction (ORR) occurs at the air cathode. The ORR process is relatively complicated. It is generally believed that the oxygen reduction reaction mainly includes a four-electron p...

Examples

Embodiment 1

[0033]To prepare an Ag / CNT catalyst with an Ag content of 5wt%, firstly take a certain amount of CNT and disperse it into a mixed acid solution of 100ml of concentrated sulfuric acid (98wt%) and 33ml of concentrated nitric acid (65wt%), then magnetically stir for 6 hours at room temperature, and use a vacuum pump Suction filtration, repeated washing with deionized water and absolute ethanol, and dry the filter cake in a vacuum drying oven at 80°C for 12 hours when the filtrate is neutral. Take 160mg of the above-mentioned treated CNT, disperse it into 100ml of deionized water, and ultrasonicate for 30min to obtain a CNT solution; then take 13.8mg of silver nitrate and dissolve it in 20ml of deionized water, and take 0.119g of sodium citrate dihydrate solution into 15ml of deionized water , the silver nitrate solution, the sodium citrate dihydrate solution and the CNT solution were mixed and stirred for 20 minutes, and then the mixed solution was put into an ice-water bath and s...

Embodiment 2

[0035] To prepare an Ag / CNT catalyst with an Ag content of 10wt%, first take a certain amount of CNT and disperse it into a mixed acid solution of 100ml of concentrated sulfuric acid (98wt%) and 33ml of concentrated nitric acid (65wt%), then magnetically stir for 6 hours at room temperature, and use a vacuum pump Suction filtration, repeated washing with deionized water and absolute ethanol, and dry the filter cake in a vacuum drying oven at 80°C for 12 hours when the filtrate is neutral. Take 160 mg of the above-mentioned treated CNT, disperse it into 100 ml of deionized water, and ultrasonicate for 30 minutes to obtain a CNT solution; then take 28.0 mg of silver nitrate and dissolve it in 20 ml of deionized water, and at the same time, take 0.242 g of sodium citrate dihydrate solution into 20 ml of deionized water , the silver nitrate solution, the sodium citrate dihydrate solution and the CNT solution were mixed and stirred for 30 minutes, and then the mixed solution was put...

Embodiment 3

[0037] To prepare an Ag / CNT catalyst with an Ag content of 15wt%, firstly take a certain amount of CNT and disperse it into a mixed acid solution of 100ml of concentrated sulfuric acid (98wt%) and 33ml of concentrated nitric acid (65wt%), then magnetically stir for 6 hours at room temperature, and use a vacuum pump Suction filtration, repeated washing with deionized water and absolute ethanol, and dry the filter cake in a vacuum drying oven at 80°C for 12 hours when the filtrate is neutral. Take 160mg of the above-mentioned treated CNT, disperse it into 100ml of deionized water, and ultrasonicate for 30min to obtain a CNT solution; then take 44.4mg of silver nitrate and dissolve it in 25ml of deionized water, and at the same time take 0.355g of sodium citrate dihydrate solution into 25ml of deionized water , after mixing and stirring the silver nitrate solution, the sodium citrate dihydrate solution and the CNT solution for 40 minutes, put the mixed solution into an ice-water b...

technical field

[0001] The invention relates to the fields of chemical power sources and electrochemical catalysis, in particular to an oxygen reduction catalyst for a zinc-air battery and a preparation method thereof. Background technique

[0002] As a metal fuel cell, zinc-air battery has a high specific energy (its theoretical specific energy is as high as 1350WhKg -1 ), low cost, environmental friendliness, and mechanical replacement (fast charging of zinc-air batteries by replacing fully discharged zinc anodes), etc., have attracted the attention of domestic and foreign researchers in recent years. A zinc-air battery consists of three parts: a zinc metal anode, an alkaline electrolyte, and an air cathode. During battery discharge, zinc dissolution occurs at the zinc anode and oxygen reduction reaction (ORR) occurs at the air cathode. The ORR process is relatively complicated. It is generally believed that the oxygen reduction reaction mainly includes a four-electron p...

Examples

Embodiment 1

[0033]To prepare an Ag / CNT catalyst with an Ag content of 5wt%, firstly take a certain amount of CNT and disperse it into a mixed acid solution of 100ml of concentrated sulfuric acid (98wt%) and 33ml of concentrated nitric acid (65wt%), then magnetically stir for 6 hours at room temperature, and use a vacuum pump Suction filtration, repeated washing with deionized water and absolute ethanol, and dry the filter cake in a vacuum drying oven at 80°C for 12 hours when the filtrate is neutral. Take 160mg of the above-mentioned treated CNT, disperse it into 100ml of deionized water, and ultrasonicate for 30min to obtain a CNT solution; then take 13.8mg of silver nitrate and dissolve it in 20ml of deionized water, and take 0.119g of sodium citrate dihydrate solution into 15ml of deionized water , the silver nitrate solution, the sodium citrate dihydrate solution and the CNT solution were mixed and stirred for 20 minutes, and then the mixed solution was put into an ice-water bath and s...

Embodiment 2

[0035] To prepare an Ag / CNT catalyst with an Ag content of 10wt%, first take a certain amount of CNT and disperse it into a mixed acid solution of 100ml of concentrated sulfuric acid (98wt%) and 33ml of concentrated nitric acid (65wt%), then magnetically stir for 6 hours at room temperature, and use a vacuum pump Suction filtration, repeated washing with deionized water and absolute ethanol, and dry the filter cake in a vacuum drying oven at 80°C for 12 hours when the filtrate is neutral. Take 160 mg of the above-mentioned treated CNT, disperse it into 100 ml of deionized water, and ultrasonicate for 30 minutes to obtain a CNT solution; then take 28.0 mg of silver nitrate and dissolve it in 20 ml of deionized water, and at the same time, take 0.242 g of sodium citrate dihydrate solution into 20 ml of deionized water , the silver nitrate solution, the sodium citrate dihydrate solution and the CNT solution were mixed and stirred for 30 minutes, and then the mixed solution was put...

Embodiment 3

[0037] To prepare an Ag / CNT catalyst with an Ag content of 15wt%, firstly take a certain amount of CNT and disperse it into a mixed acid solution of 100ml of concentrated sulfuric acid (98wt%) and 33ml of concentrated nitric acid (65wt%), then magnetically stir for 6 hours at room temperature, and use a vacuum pump Suction filtration, repeated washing with deionized water and absolute ethanol, and dry the filter cake in a vacuum drying oven at 80°C for 12 hours when the filtrate is neutral. Take 160mg of the above-mentioned treated CNT, disperse it into 100ml of deionized water, and ultrasonicate for 30min to obtain a CNT solution; then take 44.4mg of silver nitrate and dissolve it in 25ml of deionized water, and at the same time take 0.355g of sodium citrate dihydrate solution into 25ml of deionized water , after mixing and stirring the silver nitrate solution, the sodium citrate dihydrate solution and the CNT solution for 40 minutes, put the mixed solution into an ice-water b...

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