CN103801342A - Method for preparing porous material through animal bone and application of porous material as electrode catalyst of fuel cell - Google Patents

Abstract

The invention provides a method for preparing porous materials from animal bones, which is to remove the impurities on the surface of the animal bones and then mash them, treat them at 500-1000°C for 1-3 hours under the protection of nitrogen, and then ball-mill them in a ball mill for 6 hours. ~10h; then acid treatment for 12~72h; washed with distilled water until neutral, then dried. Experimental determination shows better oxygen reduction performance with the porous material of the present invention as the electrode of the fuel cell than the traditional commercial XC-72 carbon powder electrode, and the catalytic activity of oxygen reduction is obviously improved. Therefore, as the electrode catalyst of the fuel cell, it has low cost. , high performance and other characteristics, it is helpful for the popularization and application of fuel cells. In addition, the porous material of the present invention uses discarded animal bones as raw materials, which not only reduces the production cost of the porous material, but also solves the problem of waste disposal in real life, reduces environmental pollution, and truly realizes the resource utilization of turning waste into treasure idea.

Description

Method for preparing porous material from animal bone and its application as fuel cell electrode catalyst

technical field

The invention belongs to the technical field of new materials, and relates to a method for preparing porous materials from animal bones; the invention also relates to the application of the porous materials as fuel cell electrode catalysts. the

Background technique

Fuel cell is a new type of power generation device with high working efficiency, environmental friendliness and fast response speed. It can directly convert chemical energy into electrical energy, so it has become the main energy source in the 21st century. In addition, fuel cells also have unique advantages: use at room temperature, convenient fuel carrying and replenishment, high volume and weight specific energy density, weak infrared signal, etc. , communications and other fields have excellent potential application prospects.

The electrode catalyst is an important part of the fuel cell, which directly affects the performance, efficiency, stability and service life of the fuel cell. Pt catalyst is a relatively mature commercial catalyst, which has many applications in fuel cell catalysis, especially for methanol catalytic oxidation, and has better stability in acidic environment. However, Pt is an expensive rare metal, and the cost of the catalyst accounts for 30% to 45% of the cost of the low-temperature fuel cell. Therefore, the development of fuel cell catalysts with low cost and high performance has become a hot spot in fuel cell research. the

Porous material is a material with a network structure of interpenetrating or closed pores, and the boundaries or surfaces of the pores are composed of pillars or plates. A typical pore structure is a two-dimensional structure formed by the aggregation of a large number of polygonal pores on a plane, which is called a "honeycomb" material because of its shape similar to the hexagonal structure of a honeycomb. More generally, a three-dimensional structure formed by the accumulation of a large number of polyhedral-shaped pores in space is usually called a "foam" material. Porous materials have unique optical properties, so they have good application prospects in making porous electrodes for fuel cells.

my country is the world's largest carnivorous country, with more than 15 million tons of animal bones produced every year. At present, the processing of these animal bones is mainly discarded as waste, which not only pollutes the environment, but also causes waste of origin. Therefore, the resource utilization of these animal bones is of great significance. Animal bone (ie, bone tissue) is composed of a mixture of living cells and minerals (mainly calcium and scale), mainly calcium hydroxyphosphate (Ca ₁₀ (PO ₄ ) ₆ (OH) ₂ ), which give bone its The solid physical properties make calcium hydroxyphosphate not easy to decompose during the calcination process, and the gas generated during the calcination process penetrates into it to make a porous structure. Therefore, the use of animal bones to prepare porous materials can not only reduce the cost of porous materials, but also The resource utilization of animal bones can also be realized.

Contents of the invention

The first object of the present invention is to provide a method for preparing porous materials from animal bones;

Another object of the present invention is to provide the application of the porous material as a fuel cell electrode catalyst.

The preparation method of the porous material of the present invention is to remove the impurities on the surface of the animal flesh and blood, put it in a tube furnace, and under the protection of nitrogen, treat it at a high temperature of 500-1000 °C for 1-3 hours, and then put it in a ball mill. Ball milling for 6-10 hours; then acid treatment for 12-72 hours; washing with distilled water to make it neutral, and then drying.

The animal bones are pig bones, beef bones, fish bones, and sheep bones.

The acid treatment is first treated with 1-5 mol/L HNO ₃ for 12-72 h, and then treated with 1-5 mol/L HCl for 12-72 h;

The drying is carried out in a blast oven at 50-70°C.

The physical characterization and performance test of the porous material prepared by the present invention are carried out below.

1. X-ray diffraction

Fig. 1 is an X-ray diffraction diagram of the porous material prepared in the present invention. It can be seen from Figure 1 that many peaks appear after direct carbonization, among which the peak corresponding to "◆" is the peak of calcium hydroxyphosphate.

2. Scanning electron microscope (SEM) image

Fig. 2 is a scanning electron microscope (SEM) image of the porous material prepared in the present invention. It can be seen from Figure 2 that the material prepared by the present invention has a porous structure.

3. Nitrogen adsorption and desorption curve and pore size distribution diagram

Fig. 3 is the nitrogen elution adsorption curve and the pore size distribution diagram (BET) figure of the porous material prepared by the present invention. It can be seen from the figure that the pore diameter of the material is about 3.18 nm, and it can be seen that the material is a mesoporous material. In addition, Its specific surface area is 294.074 m ² g ^-1 .

4. ORR test

Fig. 3 is the ORR test of the porous material prepared by the present invention in a 0.1 mol/L KOH solution. It can be seen from Figure 3 that compared with the traditional XC-72, the porous material prepared by the present invention has better ORR performance, and its onset potential is advanced by 111.7 mV.

In summary, the porous material prepared by the present invention has an obvious pore structure, which contributes to the increase of the specific surface area; the oxygen-containing functional groups in it are increased by _HNO3 treatment, and the presence of P element also plays a role in its ORR performance. A certain boost. Experimental determination, with porous material of the present invention as the electrode material of fuel cell, show better oxygen reduction performance than traditional commercial XC-72 carbon powder electrode, oxygen reduction catalytic activity obviously improves, therefore, as the electrode catalyst of fuel cell, The invention has the characteristics of low cost and high performance, and is helpful for popularizing and applying the fuel cell. In addition, the porous material of the present invention uses discarded animal bones as raw materials, which not only reduces the production cost of porous materials, but also solves the problem of waste disposal in real life, reduces environmental pollution, and truly realizes the resource utilization of turning waste into treasure idea.

Description of drawings

Fig. 1 is an X-ray diffraction diagram of the porous material prepared in the present invention.

Fig. 2 is a scanning electron microscope (SEM) image of the porous material prepared in the present invention.

Fig. 3 is the nitrogen adsorption-desorption curve and pore size distribution diagram (BET) figure of the porous material prepared by the present invention

Fig. 4 is a comparison chart of the ORR test of the porous material prepared by the present invention in 0.1 mol/L KOH solution and the traditional XC-72.

Detailed ways

Taking pig bones as an example, the preparation method of the porous material of the present invention will be further described through specific examples.

Example 1

The collected pig bones were crushed after removing the surface impurities, placed in a tube furnace, under the protection of nitrogen, treated at 800 °C for 2 h at high temperature, and then ball milled in a ball mill for 6-10 h; the obtained samples were washed with 3 mol /L of HNO ₃ for 24 h, then washed with distilled water to make it neutral, and dried in a blast oven at 60 °C.

When ORR was tested in 0.1 mol/L KOH solution, it was found that the onset potential was 35 mV earlier than that of XC-72, which may be due to the incomplete dissolution of calcium phosphate in the bone.

Example 2

The collected pig bones were crushed after removing the surface impurities, placed in a tube furnace, under the protection of nitrogen, treated at 800 °C for 2 h at high temperature, and then ball milled in a ball mill for 6-10 h; the obtained samples were first used for 3 mol/L HNO ₃ was treated for 24 h, and then treated with 2 mol/L HCl for 72 h, then washed with distilled water to make it neutral, and dried in a blast oven at 60 °C.

When ORR was tested in 0.1 mol/L KOH solution, it was found that the onset potential was 111.7 mV earlier than that of XC-72. This is mainly because the oxygen-containing functional groups were increased by treatment with _HNO3 , followed by HCl treatment to completely dissolve calcium phosphate, forming a larger pore structure, thereby increasing its specific surface area, and finally further improving the ORR performance.

Example 3

The collected pig bones were crushed after removing the surface impurities, placed in a tube furnace, under the protection of nitrogen, treated at 800 °C for 2 h at high temperature, and then ball milled in a ball mill for 6-10 h; the obtained samples were used for 2 mol/L HCl for 72 h, then washed with distilled water to make it neutral, and dried in a blast oven at 60 °C.

Testing ORR in 0.1 mol/L KOH solution found that compared with XC-72, its onset potential was advanced by 68.4 mV, which was mainly due to the complete dissolution of calcium phosphate by HCl treatment, forming a pore structure, thereby increasing its The specific surface area finally increases the performance, but it is not as good as the sample obtained after nitric acid treatment and then hydrochloric acid treatment.

Example 4

The collected pig bones were crushed after removing the impurities on the surface, placed in a tube furnace, treated at 700 °C for 2 h under the protection of nitrogen, and then ball milled in a ball mill for 6 h; /L HNO ₃ for 24 h, and then 3 mol/L HCl for 72 h, then washed with distilled water to make it neutral, and dried in a blast oven at 60 °C.

When ORR was tested in 0.1 mol/L KOH solution, compared with XC-72, its onset potential was advanced by 98.4 mV.

Example 5

The collected pig bones were crushed after removing the impurities on the surface, placed in a tube furnace, treated at 900°C for 2 h under the protection of nitrogen, and then ball milled in a ball mill for 6 h; /L HNO ₃ for 24 h, and then 3 mol/L HCl for 72 h, then washed with distilled water to make it neutral, and dried in a blast oven at 60 °C.

When ORR was tested in 0.1 mol/L KOH solution, compared with XC-72, its onset potential was advanced by 100.1 mV.

Example 6

The collected pig bones were crushed after removing the impurities on the surface, placed in a tube furnace, treated at 800 °C for 1 h under the protection of nitrogen, and then ball milled in a ball mill for 6 h; the obtained samples were first treated with 3 mol /L HNO ₃ for 24 h, and then 3 mol/L HCl for 48 h, then washed with distilled water to make it neutral, and dried in a blast oven at 60 °C.

When ORR was tested in 0.1 mol/L KOH solution, compared with XC-72, its onset potential was advanced by 65.6 mV.

Example 7

The collected pig bones were crushed after removing the impurities on the surface, placed in a tube furnace, treated at 800°C for 3 h under the protection of nitrogen, and then ball milled in a ball mill for 6 h; /L HNO ₃ for 24 h, and then 3 mol/L HCl for 48 h, then washed with distilled water to make it neutral, and dried in a blast oven at 60 °C.

When ORR was tested in 0.1 mol/L KOH solution, compared with XC-72, its onset potential was advanced by 93.1mV.

Example 8

The collected pig bones were crushed after removing the impurities on the surface, placed in a tube furnace, under the protection of nitrogen, treated at 800 °C for 2 h at high temperature, and then ball milled in a ball mill for 6 h; /L HNO ₃ for 24 h, and then 3 mol/L HCl for 72 h, then washed with distilled water to make it neutral, and dried in a blast oven at 60 °C.

When ORR was tested in 0.1 mol/L KOH solution, compared with XC-72, its onset potential was advanced by 76.6 mV.

Example 9

The collected pig bones were crushed after removing the impurities on the surface, placed in a tube furnace, treated at 800 °C for 2 h under the protection of nitrogen, and then ball milled in a ball mill for 6 h; /L HNO ₃ for 24 h, and then 3 mol/L HCl for 72 h, then washed with distilled water to make it neutral, and dried in a blast oven at 60 °C.

When ORR was tested in 0.1 mol/L KOH solution, compared with XC-72, its onset potential was advanced by 110.3mV.

Example 10

The collected pig bones were crushed after removing the impurities on the surface, placed in a tube furnace, under the protection of nitrogen, treated at 800 °C for 2 h at high temperature, and then ball milled in a ball mill for 6 h; /L HNO ₃ for 24 h, and then 3 mol/L HCl for 48 h, then washed with distilled water to make it neutral, and dried in a blast oven at 60 °C.

When ORR was tested in 0.1 mol/L KOH solution, compared with XC-72, its onset potential was advanced by 74.5mV.

Example 11

The collected pig bones were crushed after removing the surface impurities, placed in a tube furnace, under the protection of nitrogen, treated at 800°C for 2 h at high temperature, and then ball milled in a ball mill for 6 h; L of HNO ₃ was treated for 24 h, and then treated with 3 mol/L HCl for 96 h, then washed with distilled water to make it neutral, and dried in a blast oven at 60 °C.

When ORR was tested in 0.1 mol/L KOH solution, compared with XC-72, its onset potential was advanced by 83.6mV.

A large number of experiments have shown that the ORR performance of the porous material prepared by the above method is basically similar to that of pig bone, using bovine bone as raw material. the

Claims (5)

1. utilizing animal bone to prepare the method for porous material, is to smash to pieces after animal kindred is removed to the miscellaneous material on top layer, is placed in tube furnace, under nitrogen protection, processes 1～3 h at 500～1000 ℃, then in ball mill ball milling 6～10 h; Then acid treatment 12～72 h; Wash into neutrality with distillation, dry and get final product.

2. utilize as claimed in claim 1 animal bone to prepare the method for porous material, it is characterized in that: described animal bone is pig bone, Os Bovis seu Bubali, Fishbone, sheep bone.

3. utilize as claimed in claim 1 or 2 animal bone to prepare the method for porous material, it is characterized in that: described acid treatment is the HNO that first uses 1～5 mol/L ₃process 12～72 h, then with HCl processing 12～72 h of 1～5 mol/L.

4. utilize as claimed in claim 1 or 2 animal bone to prepare the method for porous material, it is characterized in that: described oven dry is in convection oven, at 50～70 ℃, carry out.

5. the porous material that as claimed in claim 1 prepared by method is as the application of electrode catalyst of fuel cell.

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