Carbon-based non-metallic catalyst, its preparation method and application in fuel cell cathode

Abstract

The application provides a carbon-based non-metallic catalyst and a preparation method and application in a fuel cell cathode thereof, and relates to the technical field of fuel cell catalysts.The preparation method comprises the following steps: mixing a molecular sieve, a carbon source, a nitrogen source and concentrated sulfuric acid in a liquid environment, and then evaporating dry to obtain a composite precursor; calcining the composite precursor at 600 DEG C-900 DEG C under nitrogen, and then etching in a sodium hydroxide solution at 70 DEG C-90 DEG C to obtain a composite intermediate; and calcining the composite intermediate at 600 DEG C-900 DEG C under ammonia, and then cooling to obtain the carbon-based non-metallic catalyst.The application co-dopes nitrogen and sulfur elements on the carbon material with a molecular sieve skeleton by using the molecular sieve as a template agent, so that the carbon-based non-metallic catalyst not only has the high specific surface area and unique pore structure of the molecular sieve, but also can improve the catalytic activity, does not need to use a noble metal material, reduces the manufacturing cost, and can avoid the risk of poisoning of the metal active sites.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fuel cell catalyst, in particular to a carbon-based non-metallic catalyst, a preparation method thereof and application thereof in a fuel cell cathode. BACKGROUND

[0002] Fuel cell is a kind of promising clean energy, which has the advantage of high energy rate, but is limited by the slow action of cathode oxygen reduction reaction, so that the noble metal Pt is mostly used as the cathode catalyst in the market, and due to this, the large-scale application of fuel cell is limited, in order to solve this problem, researchers pay attention to how to reduce or not use noble metal, the carbon-based non-metallic catalyst is a kind of catalyst without using metal, which can have higher activity through heteroatom doping, defect making and other methods.

[0003] Tian X, Zhao X, Su Y Q, et al. Engineering bunched Pt-Ni alloy nanocages for efficient oxygen reduction in practical fuel cells SI. pdf [J]. Science, 2019, 366(6467): 850-856. DOI: 10.1126 / science.aaw7493. reported a catalyst for fuel cell cathode, which is one-dimensional bunched platinum-nickel alloy nanocage with platinum shell structure, which has high activity and reduces the amount of platinum, but still cannot completely not use noble metal; Liang Shuang et al. (Liang, S, et al., Highly Stable Co Single Atom Confined in Hierarchical Carbon Molecular Sieve as Efficient Electrocatalysts in Metal-Air Batteries. Advanced Energy Materials, 2022. 12(11)) doped non-noble metal Co into carbon molecular sieve, which benefits from the unique pore of carbon molecular sieve, so that Co-doped carbon molecular sieve has higher oxygen reduction activity, but its limiting current density has not reached the level of platinum-based catalyst; Han-Ik Joh (Lee H R, Han S, Lee J Y, et al. Effect of pre-annealing on chemical configuration and heteroatom doping of highly active carbon catalysts for the oxygen reduction reaction [J]. Journal of Industrial and Engineering Chemistry, 2023, 128: 542-549. DOI: 10.1016 / j.jiec.2023.08.019.) et al. reported a catalyst of heteroatom-doped graphene oxide, which can perform oxygen reduction reaction without using metal, providing a new choice for fuel cell cathode catalyst.

[0004] Although the above-mentioned catalysts have shown certain potential in the field of fuel cell cathode catalysts, they each have some shortcomings. Although the platinum-nickel alloy nanocage reduces the amount of platinum used, it still cannot get rid of the dependence on noble metals and is high in cost. Although the Co-doped carbon molecular sieve improves the oxygen reduction activity, its limiting current density has not yet reached the standard of platinum-based catalysts. Although the heteroatom-doped graphene oxide provides a new direction for metal-free catalysts, the complexity of the preparation process and long-term stability still need to be further explored and optimized. Therefore, in the research and development process of fuel cell cathode catalysts, continuous exploration and innovation are still needed to seek more efficient, stable and cost-effective catalyst materials. Therefore, there is an urgent need to provide a scheme to improve the above-mentioned problems. SUMMARY

[0005] The purpose of the present application is to provide a carbon-based non-metallic catalyst, its preparation method and application in fuel cell cathodes. By using molecular sieves as a template agent, nitrogen and sulfur elements are co-doped on carbon materials with a molecular sieve skeleton. Not only does it have a high specific surface area and unique pore structure of molecular sieves, but it also improves catalytic activity, does not require the use of noble metal materials, reduces manufacturing costs, and avoids the risk of metal active sites being poisoned.

[0006] In a first aspect, the present application provides a preparation method of a carbon-based non-metallic catalyst, comprising: mixing molecular sieves, a carbon source, a nitrogen source and concentrated sulfuric acid in a liquid environment and then evaporating to obtain a composite precursor; calcining the composite precursor at 600-900 DEG C under nitrogen, and then etching in a sodium hydroxide solution at 70-90 DEG C to obtain a composite intermediate; calcining the composite intermediate at 600-900 DEG C under ammonia and then cooling to obtain the carbon-based non-metallic catalyst.

[0007] Optionally, when the molecular sieves, the carbon source, the nitrogen source and the concentrated sulfuric acid are mixed in the liquid environment, the molecular sieves, the carbon source and the nitrogen source are dispersed in the liquid environment in advance, and then the concentrated sulfuric acid is added for mixing.

[0008] Optionally, the molecular sieves include MCM-48.

[0009] Optionally, the carbon source includes one of sucrose, glucose, starch and glucosamine hydrochloride.

[0010] Optionally, the nitrogen source includes one of urea and melamine.

[0011] Optionally, the mass ratio of the carbon source to the nitrogen source is 1:(0.1-2).

[0012] Optionally, the preparation method of the molecular sieves comprises: mixing and dissolving hexadecyltrimethylammonium bromide and sodium hydroxide to obtain a mixed solution; adding a silicon source into the mixed solution for hydrothermal reaction, and then separating, drying and calcining to obtain the molecular sieves.

[0013] Optionally, the silicon source comprises one of silica sol and tetraethyl orthosilicate.

[0014] Optionally, the mass ratio of the silicon source to the sodium hydroxide is 1:(0.02-0.1).

[0015] Optionally, the mass ratio of the silicon source to the sodium hydroxide is 1:(0.02-0.1).

[0016] Optionally, the pH of the mixed solution is 12.5-14.

[0017] Optionally, the silicon source is added into the mixed solution and the hydrothermal reaction is carried out at 140℃-160℃.

[0018] Optionally, the silicon source is added into the mixed solution and the hydrothermal reaction is carried out for 20h-28h.

[0019] Optionally, the molecular sieve is obtained by calcining at 400℃-700℃ after separation and drying.

[0020] Optionally, the molecular sieve is obtained by calcining at 400℃-700℃ after separation and drying.

[0021] Optionally, the molecular sieve, the carbon source, the nitrogen source and the concentrated sulfuric acid are mixed in a liquid environment, and then the mixture is independently incubated at 90℃-110℃ and 140℃-160℃ for 5h-8h.

[0022] Optionally, the composite precursor is heated to 600℃-900℃ at a rate of 1℃ / min-10℃ / min under a nitrogen atmosphere.

[0023] Optionally, the composite intermediate is heated to 600℃-900℃ at a rate of 1℃ / min-10℃ / min under an ammonia atmosphere.

[0024] Optionally, the concentration of the sodium hydroxide solution is 1mol / L-3mol / L.

[0025] Optionally, the etching in the sodium hydroxide solution is carried out for 10h-14h.

[0026] Optionally, the etching in the sodium hydroxide solution is carried out for 10h-14h.

[0027] In a second aspect, the present application further provides a carbon-based non-metallic catalyst prepared by any of the above optional preparation methods.

[0028] In a third aspect, the present application further provides an application of a carbon-based non-metallic catalyst prepared by any of the above optional preparation methods in a fuel cell cathode. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 A flow chart of a preparation method of a carbon-based non-metallic catalyst provided by the present application is shown in the figure;

[0030] Figure 2 An SEM characterization graph of the carbon-based non-metallic catalyst prepared in Example 1 of the present application at a magnification of 50K is shown in the figure;

[0031] Figure 3 A TEM characterization graph of the carbon-based non-metallic catalyst prepared in Example 1 of the present application at a scale of 10nm is shown in the figure;

[0032] Figure 4 An XRD characterization graph of the carbon-based non-metallic catalyst prepared in Example 1 of the present application is shown in the figure;

[0033] Figure 5 A linear sweep voltammogram of the carbon-based non-metallic catalyst prepared in Example 1 of the present application is shown in the figure;

[0034] Figure 6 An activity comparison graph of the carbon-based non-metallic catalyst prepared in Example 1 of the present application and a Pt / C catalyst after methanol poisoning is shown in the figure. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme of the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are some embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments of the present application, all the other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application. Unless otherwise defined, the technical terms or scientific terms used herein should be understood as the usual meanings understood by those skilled in the art.

[0036] Reference Figure 1 The present application provides a preparation method of a carbon-based non-metallic catalyst, which comprises the following steps:

[0037] S1, mixing molecular sieve, carbon source, nitrogen source and concentrated sulfuric acid in a liquid environment and evaporating to dryness to obtain a composite precursor;

[0038] S2, calcining the composite precursor at 600-900℃ under nitrogen, and then etching in a sodium hydroxide solution at 70-90℃ to obtain a composite intermediate;

[0039] S3, calcining the composite intermediate at 600-900℃ under ammonia and cooling to obtain a carbon-based non-metallic catalyst.

[0040] In fact, in step S1, the molecular sieve can be used as a template agent, a carbon layer is covered on the surface of the molecular sieve, and nitrogen elements and sulfur elements are introduced, so that a carbon-based skeleton material with a molecular sieve structure can be formed. In addition, by using concentrated sulfuric acid, not only can the sulfur elements be introduced, but also the dehydration property of the concentrated sulfuric acid can be used to promote the coverage and molding of the carbon source and the nitrogen source on the surface of the molecular sieve.

[0041] In fact, in the high-temperature nitrogen atmosphere in step S2, calcination is performed, which helps to form a composite carbon skeleton on the surface of the molecular sieve. At the same time, in the nitrogen atmosphere, not only can the carbon be protected, but also the nitrogen elements can be further doped. After calcination molding, etching is performed in a sodium hydroxide solution, which can remove the used molecular sieve template agent, so that the composite carbon skeleton has a pore structure similar to that of the molecular sieve.

[0042] In fact, in step S3, calcination is performed in a nitrogen atmosphere, which can further improve the binding quality of the nitrogen elements, the sulfur elements and the carbon skeleton in the composite carbon skeleton. In addition, secondary nitrogen doping treatment can be performed, and at the same time, an oxidized graphene layer can be formed at the edge position of the catalyst skeleton, so as to present a structure in which oxidized graphene and graphite coexist, and a state in which defects and pores coexist. This is conducive to exposing more active sites of the catalyst and enhancing the uniformity of the distribution of the active sites, which can significantly enhance the catalytic stability and the resistance to poisoning.

[0043] In some embodiments, when the molecular sieve, the carbon source, the nitrogen source and the concentrated sulfuric acid are mixed in a liquid environment in step S1, the molecular sieve, the carbon source and the nitrogen source are dispersed in the liquid environment in advance, and then the concentrated sulfuric acid is added for mixing. In fact, by pre-mixing the molecular sieve, the carbon source and the nitrogen source, the uniformity of the dispersion of the molecular sieve, the carbon source and the nitrogen source can be improved. After the concentrated sulfuric acid is added, the dehydration property of the concentrated sulfuric acid can be used for pre-carbonization of the carbon source and the nitrogen source, so that the carbon material and the nitrogen elements are covered and doped on the surface of the molecular sieve.

[0044] In further embodiments, the molecular sieve used includes MCM-48. In fact, the MCM-48 molecular sieve has a high specific surface area and a unique pore structure. The carbon-based non-metallic catalyst prepared by using the MCM-48 molecular sieve as a template agent can inherit the pore structure of the MCM-48, and thus can improve the uniformity and the number of active sites on the surface of the catalyst, which is conducive to improving the catalytic activity.

[0045] Specifically, the preparation method of the MCM-48 molecular sieve includes: mixing and dissolving hexadecyltrimethylammonium bromide and sodium hydroxide to obtain a mixed solution; adding a silicon source into the mixed solution to perform a hydrothermal reaction, and then separating, drying and calcining to obtain the molecular sieve. In fact, the MCM-48 molecular sieve can also be a commercially available product, or can be synthesized in a laboratory by using other conventional methods.

[0046] In fact, in the preparation of MCM-48 molecular sieve, the silicon source used includes one of silica sol and tetraethyl orthosilicate, and the mass ratio of the silicon source, cetyltrimethylammonium bromide and sodium hydroxide in the mixed solution is 1:(0.2-0.8):(0.2-0.8). In addition, the pH of the prepared mixed solution is 12.5-14.

[0047] In some embodiments, in the preparation of MCM-48 molecular sieve, cetyltrimethylammonium bromide and sodium hydroxide are mixed and dissolved in deionized water to form a mixed solution, and the amount of deionized water used is necessary to completely dissolve cetyltrimethylammonium bromide and sodium hydroxide.

[0048] In fact, in the preparation of MCM-48 molecular sieve, the silicon source is added to the mixed solution and hydrothermally reacted at 140°C-160°C for 20h-28h, and then separated, dried and calcined at 400°C-700°C to obtain MCM-48 molecular sieve. Specifically, the silicon source and the mixed solution can be hydrothermally reacted in a high-pressure reaction kettle, and after separation and drying, the temperature can be raised to 400°C-700°C at a rate of 2°C / min-8°C / min in a muffle furnace in an air atmosphere and calcined at a constant temperature.

[0049] In fact, the carbon source and nitrogen source used in step S1 can use organic reagents commonly used in the art, as long as they contain sufficient nitrogen and carbon elements. In addition, in order to reduce the preparation cost, the carbon source is preferably one of sucrose, glucose, starch and glucosamine hydrochloride, and the nitrogen source is preferably one of urea and melamine.

[0050] In some embodiments, the mass ratio of the carbon source to the nitrogen source in step S1 is 1:(0.1-2). In fact, by adjusting the amount of nitrogen source, the amount of nitrogen element doped on the carbon-based non-metallic catalyst prepared can be adjusted, so that the catalytic activity of the catalyst can be dynamically regulated.

[0051] In fact, in step S1, when the molecular sieve, the carbon source, the nitrogen source and concentrated sulfuric acid are mixed in a liquid environment, the liquid environment used can be deionized water. In addition, after mixing, they are independently incubated at 90°C-110°C and 140°C-160°C for 5h-8h, respectively, which is beneficial to uniform pre-carbonization of the carbon source and the nitrogen source by concentrated sulfuric acid, and the formation of uniform carbonized precursors on the surface of the molecular sieve.

[0052] In some embodiments, in the step S2, the composite precursor is heated to 600-900℃ at a rate of 1-10℃ / min under a nitrogen atmosphere. Specifically, the composite precursor can be transferred into the furnace of a tube furnace in advance, and after the tube furnace is replaced with nitrogen, the tube furnace is uniformly heated, and after the calcined product is cooled to room temperature, etching is performed in a 1-3 mol / L, 70-90℃ sodium hydroxide solution to remove the molecular sieve template agent in the product, and after drying, a pure composite intermediate is obtained.

[0053] In some embodiments, in the step S3, the composite intermediate is heated to 600-900℃ at a rate of 1-10℃ / min under an ammonia atmosphere.

[0054] The present application also provides a carbon-based non-metallic catalyst prepared by the preparation method of any one of the above embodiments, which comprises a carbon skeleton and doped nitrogen and sulfur elements, and the mass fraction of the doped nitrogen element is 2-8%, and the mass fraction of the doped sulfur element is 0.5-2%. In addition, the carbon skeleton has a molecular sieve morphology.

[0055] Embodiment 1

[0056] The present embodiment 1 provides a preparation method of a carbon-based non-metallic catalyst, comprising the following steps:

[0057] S0, 9.85g of cetyltrimethylammonium bromide and 1.78g of sodium hydroxide were stirred and dissolved in 120mL of deionized water to obtain a mixed solution; 20g of tetraethyl orthosilicate was added to the mixed solution and stirred for 3h, then taken out after reaction in a 150℃ hydrothermal reactor for 24h, and then filtered and washed with deionized water until the washing liquid was neutral, and then dried in an 80℃ oven to constant weight, and then transferred to a muffle furnace, which was heated to 650℃ at a rate of 5℃ / min and calcined for 3h, and then cooled to room temperature to obtain MCM-48 molecular sieve;

[0058] S1, 2g of MCM-48 molecular sieve, 1g of glucosamine hydrochloride and 1.5g of urea were added to 10mL of deionized water and stirred and mixed, and then 2mL of concentrated sulfuric acid with a concentration of 98% was added and stirred and mixed for pre-carbonization, and then placed in an 100℃ oven for 6h, and then placed in a 150℃ oven for 6h, and then cooled to room temperature to obtain a composite precursor;

[0059] S2, the composite precursor was placed in the hearth of a tube furnace, and the tube furnace was heated to 900°C at a rate of 5°C / min under a nitrogen atmosphere and kept for 2h, and then cooled to room temperature with the furnace. The obtained product was added to 100mL of a 2mol / L sodium hydroxide solution, etched in an 80°C water bath environment for 12h, and then separated by suction filtration and dried in an 80°C oven to constant weight to obtain a composite intermediate;

[0060] S3, the composite intermediate was placed in the hearth of a tube furnace, and the tube furnace was heated to 900°C at a rate of 5°C / min under an ammonia atmosphere and kept for 2h, and then cooled to room temperature with the furnace, and then ground to obtain a carbon-based non-metallic catalyst.

[0061] Example 2

[0062] This example 2 provides a preparation method of a carbon-based non-metallic catalyst, which is different from example 1 in that 11.46g of cetyltrimethylammonium bromide and 2.13g of sodium hydroxide are stirred and dissolved in 120mL of deionized water in step S0, and 2g of MCM-48 molecular sieve, 1.5g of glucosamine hydrochloride, and 1g of urea are added to 10mL of deionized water in step S1.

[0063] Example 3

[0064] This example 3 provides a preparation method of a carbon-based non-metallic catalyst, which is different from example 1 in that 32.45g of cetyltrimethylammonium bromide and 6.21g of sodium hydroxide are stirred and dissolved in 120mL of deionized water in step S0.

[0065] Example 4

[0066] This example 4 provides a preparation method of a carbon-based non-metallic catalyst, which is different from example 1 in that 7.63g of cetyltrimethylammonium bromide and 1.78g of sodium hydroxide are stirred and dissolved in 120mL of deionized water in step S0, and calcined at 650°C for 2h in a muffle furnace, and 2g of MCM-48 molecular sieve, 1.5g of glucosamine hydrochloride, and 1.5g of urea are added to 10mL of deionized water in step S1, and kept for 3h at 900°C in a muffle furnace in steps S2 and S3.

[0067] Example 5

[0068] This embodiment 5 provides a preparation method of carbon-based non-metallic catalyst, which is different from embodiment 1 in that 6.99 g of cetyltrimethylammonium bromide and 2.13 g of sodium hydroxide are stirred and dissolved in 120 mL of deionized water in step S0, 2 g of MCM-48 molecular sieve, 1.5 g of glucose, and 1.5 g of urea are added to 10 mL of deionized water in step S1, and the temperature is kept at 900°C in a muffle furnace for 3 h in steps S2 and S3.

[0069] Embodiment 6

[0070] This embodiment 6 provides a preparation method of carbon-based non-metallic catalyst, which is different from embodiment 1 in that 10.54 g of cetyltrimethylammonium bromide and 1.56 g of sodium hydroxide are stirred and dissolved in 120 mL of deionized water in step S0, and 2 g of MCM-48 molecular sieve, 1.5 g of sucrose, and 1.5 g of urea are added to 10 mL of deionized water in step S1.

[0071] Embodiment 7

[0072] This embodiment 7 provides a preparation method of carbon-based non-metallic catalyst, which is different from embodiment 1 in that 11.89 g of cetyltrimethylammonium bromide and 2.01 g of sodium hydroxide are stirred and dissolved in 120 mL of deionized water in step S0, and are calcined at 650°C for 2 h in a muffle furnace, 2 g of MCM-48 molecular sieve, 1.5 g of starch, and 1.5 g of urea are added to 10 mL of deionized water in step S1.

[0073] Embodiment 8

[0074] This embodiment 8 provides a preparation method of carbon-based non-metallic catalyst, which is different from embodiment 1 in that 8.34 g of cetyltrimethylammonium bromide and 1.92 g of sodium hydroxide are stirred and dissolved in 120 mL of deionized water in step S0, and are calcined at 600°C for 2 h in a muffle furnace, 2 g of MCM-48 molecular sieve, 1.5 g of glucosamine hydrochloride, and 1.5 g of melamine are added to 10 mL of deionized water in step S1, and the temperature is kept at 850°C in a muffle furnace for 2 h in steps S2 and S3.

[0075] Embodiment 9

[0076] This embodiment 9 provides a preparation method of carbon-based non-metallic catalyst, which is different from embodiment 1 in that 12.02 g of cetyltrimethylammonium bromide and 1.67 g of sodium hydroxide are stirred and dissolved in 120 mL of deionized water to prepare a mixed solution, 20 g of nano-silicon dioxide is added into the mixed solution, and the mixed solution is calcined in a muffle furnace at a rate of 3 ℃ / min and at 600 ℃ for 2 h in step S0, 2 g of MCM-48 molecular sieve, 1.5 g of glucose and 1.5 g of melamine are added into 10 mL of deionized water in step S1, and the mixture is kept in the muffle furnace at 850 ℃ for 2 h in step S2 and step S3.

[0077] Embodiment 10

[0078] This embodiment 10 provides a preparation method of carbon-based non-metallic catalyst, which is different from embodiment 1 in that 7.21 g of cetyltrimethylammonium bromide and 2.25 g of sodium hydroxide are stirred and dissolved in 120 mL of deionized water to prepare a mixed solution, 20 g of nano-silicon dioxide is added into the mixed solution, and the mixed solution is calcined in a muffle furnace at a rate of 3 ℃ / min and at 600 ℃ for 2 h in step S0, 2 g of MCM-48 molecular sieve, 1.5 g of sucrose and 1.5 g of melamine are added into 10 mL of deionized water in step S1, and the mixture is kept in the muffle furnace at 850 ℃ for 2 h in step S2 and step S3.

[0079] Embodiment 11

[0080] This embodiment 11 provides a preparation method of carbon-based non-metallic catalyst, which is different from embodiment 1 in that 9.15 g of cetyltrimethylammonium bromide and 1.54 g of sodium hydroxide are stirred and dissolved in 120 mL of deionized water to prepare a mixed solution, 20 g of nano-silicon dioxide is added into the mixed solution, and the mixed solution is calcined in a muffle furnace at a rate of 3 ℃ / min and at 600 ℃ for 2 h in step S0, 2 g of MCM-48 molecular sieve, 1.5 g of starch and 1.5 g of melamine are added into 10 mL of deionized water in step S1, and the mixture is kept in the muffle furnace at 850 ℃ for 2 h in step S2 and step S3.

[0081] Embodiment 12

[0082] This embodiment 12 provides a preparation method of carbon-based non-metallic catalyst, which is different from embodiment 1 in that 10.12 g of cetyltrimethylammonium bromide and 2.30 g of sodium hydroxide are stirred and dissolved in 120 mL of deionized water to prepare a mixed solution, 20 g of nano-silicon dioxide is added into the mixed solution, and the mixed solution is calcined in a muffle furnace at a rate of 5 ℃ / min and at 600 ℃ for 2 h in step S0, 2 g of MCM-48 molecular sieve, 1.5 g of glucosamine hydrochloride and 1 g of urea are added into 10 mL of deionized water in step S1, and the mixture is kept in the muffle furnace at 800 ℃ for 3 h in step S2 and step S3.

[0083] Example 13

[0084] This example 13 provides a preparation method of carbon-based non-metallic catalyst, which is different from example 1 in that 12.27 g of cetyltrimethylammonium bromide and 1.89 g of sodium hydroxide are stirred and dissolved in 120 mL of deionized water to prepare a mixed solution, 20 g of nano-silicon dioxide is added to the mixed solution, and the temperature is raised to 600°C at a rate of 5°C / min in a muffle furnace for calcination for 3 h, 2 g of MCM-48 molecular sieve, 1.5 g of glucose, and 1 g of urea are added to 10 mL of deionized water in step S1, and the muffle furnace is kept at 800°C for 3 h in steps S2 and S3.

[0085] Example 14

[0086] This example 14 provides a preparation method of carbon-based non-metallic catalyst, which is different from example 1 in that 8.87 g of cetyltrimethylammonium bromide and 2.07 g of sodium hydroxide are stirred and dissolved in 120 mL of deionized water to prepare a mixed solution, and the temperature is raised to 550°C at a rate of 5°C / min in a muffle furnace for calcination for 3 h, 2 g of MCM-48 molecular sieve, 1.5 g of sucrose, and 1 g of urea are added to 10 mL of deionized water in step S1, and the muffle furnace is kept at 800°C for 2 h in steps S2 and S3.

[0087] Example 15

[0088] This example 15 provides a preparation method of carbon-based non-metallic catalyst, which is different from example 1 in that 7.58 g of cetyltrimethylammonium bromide and 1.71 g of sodium hydroxide are stirred and dissolved in 120 mL of deionized water to prepare a mixed solution, and the temperature is raised to 550°C at a rate of 5°C / min in a muffle furnace for calcination for 2 h, 2 g of MCM-48 molecular sieve, 1.5 g of starch, and 1 g of urea are added to 10 mL of deionized water in step S1, and the muffle furnace is kept at 800°C for 2 h in steps S2 and S3.

[0089] Example 16

[0090] This embodiment 16 provides a preparation method of carbon-based non-metallic catalyst, which is different from embodiment 1 in that 9.43 g of cetyltrimethylammonium bromide and 1.62 g of sodium hydroxide are stirred and dissolved in 120 mL of deionized water to prepare a mixed solution, 20 g of nano silicon dioxide is added into the mixed solution, and the temperature is raised to 550°C at a rate of 5°C / min in a muffle furnace for calcination for 2 h, 2 g of MCM-48 molecular sieve, 1.5 g of glucosamine hydrochloride and 1.0 g of melamine are added into 10 mL of deionized water in step S1, and the temperature is kept at 750°C in a muffle furnace for 2 h in step S2 and step S3.

[0091] Embodiment 17

[0092] This embodiment 17 provides a preparation method of carbon-based non-metallic catalyst, which is different from embodiment 1 in that 11.23 g of cetyltrimethylammonium bromide and 2.21 g of sodium hydroxide are stirred and dissolved in 120 mL of deionized water to prepare a mixed solution, 20 g of nano silicon dioxide is added into the mixed solution, and the temperature is raised to 550°C at a rate of 5°C / min in a muffle furnace for calcination for 2 h, 2 g of MCM-48 molecular sieve, 1.5 g of glucose and 1.0 g of melamine are added into 10 mL of deionized water in step S1, and the temperature is kept at 750°C in a muffle furnace for 2 h in step S2 and step S3.

[0093] Embodiment 18

[0094] This embodiment 18 provides a preparation method of carbon-based non-metallic catalyst, which is different from embodiment 1 in that 7.98 g of cetyltrimethylammonium bromide and 1.97 g of sodium hydroxide are stirred and dissolved in 120 mL of deionized water, and the temperature is raised to 550°C at a rate of 5°C / min in a muffle furnace for calcination for 2 h in step S0, 2 g of MCM-48 molecular sieve, 1.5 g of sucrose and 1.0 g of melamine are added into 10 mL of deionized water in step S1, and the temperature is kept at 750°C in a muffle furnace for 2 h in step S2 and step S3.

[0095] Embodiment 19

[0096] This embodiment 19 provides a preparation method of carbon-based non-metallic catalyst, which is different from embodiment 1 in that 8.56 g of cetyltrimethylammonium bromide and 1.59 g of sodium hydroxide are stirred and dissolved in 120 mL of deionized water, and the temperature is raised to 700°C at a rate of 5°C / min in a muffle furnace for calcination for 2 h in step S0, 2 g of MCM-48 molecular sieve, 1.5 g of glucosamine hydrochloride and 1.0 g of melamine are added into 10 mL of deionized water in step S1, and the temperature is kept at 750°C in a muffle furnace for 2 h in step S2 and step S3.

[0097] Example 20

[0098] This example 20 provides a preparation method of carbon-based non-metallic catalyst, which is different from example 1 in that 35.67 g of cetyltrimethylammonium bromide and 5.33 g of sodium hydroxide are stirred and dissolved in 120 mL of deionized water to prepare a mixed solution, 20 g of nano-silicon dioxide is added to the mixed solution, and the temperature is raised to 700°C at a rate of 5°C / min in a muffle furnace for calcination for 2 h, 2 g of MCM-48 molecular sieve, 1.5 g of glucose, and 0.5 g of urea are added to 10 mL of deionized water in step S1, and the muffle furnace is kept at 650°C for 2 h in steps S2 and S3.

[0099] Example 21

[0100] This example 21 provides a preparation method of carbon-based non-metallic catalyst, which is different from example 1 in that 29.89 g of cetyltrimethylammonium bromide and 7.41 g of sodium hydroxide are stirred and dissolved in 120 mL of deionized water to prepare a mixed solution, 20 g of nano-silicon dioxide is added to the mixed solution, and the temperature is raised to 700°C at a rate of 5°C / min in a muffle furnace for calcination for 2 h, 2 g of MCM-48 molecular sieve, 1.5 g of sucrose, and 0.5 g of urea are added to 10 mL of deionized water in step S1, and the muffle furnace is kept at 650°C for 2 h in steps S2 and S3.

[0101] Example 22

[0102] This example 22 provides a preparation method of carbon-based non-metallic catalyst, which is different from example 1 in that 24.87 g of cetyltrimethylammonium bromide and 7.09 g of sodium hydroxide are stirred and dissolved in 120 mL of deionized water, and the temperature is raised to 700°C at a rate of 3°C / min in a muffle furnace for calcination for 3 h in step S0, 2 g of MCM-48 molecular sieve, 1.5 g of starch, and 0.5 g of melamine are added to 10 mL of deionized water in step S1, and the muffle furnace is kept at 650°C for 2 h in steps S2 and S3.

[0103] Example 23

[0104] This example 23 provides a preparation method of carbon-based non-metallic catalyst, which is different from example 1 in that 31.23 g of cetyltrimethylammonium bromide and 6.17 g of sodium hydroxide are stirred and dissolved in 120 mL of deionized water in step S0, and calcination is carried out at a rate of 3 ℃ / min to 700 ℃ in a muffle furnace for 3 h, 2 g of MCM-48 molecular sieve, 1.5 g of sucrose, and 0.5 g of melamine are added to 10 mL of deionized water in step S1, and the muffle furnace is kept at 650 ℃ for 2 h in step S2 and step S3.

[0105] Example 24

[0106] This example 24 provides a preparation method of carbon-based non-metallic catalyst, which is different from example 1 in that 27.34 g of cetyltrimethylammonium bromide and 7.58 g of sodium hydroxide are stirred and dissolved in 120 mL of deionized water to prepare a mixed solution, 20 g of nano-silicon dioxide is then added to the mixed solution, and calcination is carried out at a rate of 3 ℃ / min to 700 ℃ in a muffle furnace for 3 h, 2 g of MCM-48 molecular sieve, 1.5 g of starch, and 0.5 g of melamine are added to 10 mL of deionized water in step S1, and the muffle furnace is kept at 650 ℃ for 2 h in step S2 and step S3.

[0107] Comparative example 1

[0108] This comparative example 1 provides a preparation method of carbon-based non-metallic catalyst, which is different from example 1 in that in step S3, the tube furnace is heated to 900 ℃ at a rate of 5 ℃ / min under an argon atmosphere and kept for 2 h.

[0109] Comparative example 2

[0110] This comparative example 2 provides a preparation method of carbon-based non-metallic catalyst, which is different from example 1 in that 2 mL of concentrated sulfuric acid with a concentration of 98% is not added in step S1 for pre-carbonization.

[0111] Comparative example 3

[0112] This comparative example 3 provides a preparation method of carbon-based non-metallic catalyst, which is different from example 1 in that MCM-48 molecular sieve is not added in step S1.

[0113] Performance detection

[0114] The carbon-based non-metallic catalysts prepared in Examples 1 to 24 and Comparative Examples 1 to 3 were subjected to catalytic performance evaluation, including: taking 2.5 mg of the carbon-based non-metallic catalyst, 250 μL of deionized water, 750 μL of anhydrous ethanol solution and 50 μL of Nafion solution (perfluorinated resin solution) to prepare an Ink solution, and using a pipette to take 32 μL of the Ink solution onto a rotating ring disc electrode, using 0.1 mol / L potassium hydroxide solution as an electrolyte, at a rotation speed of 1600 rpm, a scan frequency of 10 mV / s, a scan range of 0-1.1 V relative to the hydrogen electrode, the limiting current density was detected, and the results are shown in Table 1.

[0115] The carbon-based non-metallic catalyst prepared in Example 1 was observed using a scanning electron microscope at a magnification of 50K, and the SEM image is shown in Figure 2 The carbon-based non-metallic catalyst prepared in Example 1 was observed using a transmission electron microscope at a scale of 10 nm, and the TEM image is shown in Figure 3 The carbon-based non-metallic catalyst prepared in Example 1 was subjected to XRD characterization, as shown in Figure 4 The carbon-based non-metallic catalyst prepared in Example 1 was subjected to linear voltammetry scan test, as shown in Figure 5 The carbon-based non-metallic catalyst prepared in Example 1 and the Pt / C catalyst (purchased from Suzhou Shengernuo Technology Co., Ltd., model SPT20X) were subjected to activity detection after methanol poisoning, as shown in Figure 6

[0116] Table 1 Limiting current density results

[0117]

[0118]

[0119] As can be seen from Figure 2 and Figure 3 , the carbon-based non-metallic catalyst prepared in Example 1 has a graphite-like structure, and the spiral curved pore wall structure of MCM-48 molecular sieve can be observed, which indicates that the synthesized carbon-based non-metallic catalyst has a molecular sieve structure. As can be seen from Figure 4 , the 002 plane and 001 plane of graphite can be observed at 24.7° and 43.7°, respectively, and a broad diffraction peak of graphene oxide-like appears at 10.9°. As can be seen from Figure 5 , the limiting current density of the carbon-based non-metallic catalyst prepared in Example 1 is -6.2 mA / cm 2 , the half-wave potential is 0.77 V, and the initial potential is 0.91 V. As can be seen from Figure 6 , the carbon-based non-metallic catalyst prepared in Example 1 has excellent resistance to methanol poisoning.​

[0120] While the embodiments of the application have been illustrated and described in detail, it will be readily apparent to those skilled in the art that various modifications and changes can be made to the embodiments without departing from the scope and spirit of the application, as described in the claims. Moreover, the application described is not limited in its application to the details set forth in the description or illustrated in the drawings. The application is capable of other embodiments and of being practiced or carried out in various ways.

Claims

1. A method for preparing a carbon-based non-metallic catalyst, characterized by, Comprise: The molecular sieve, carbon source, nitrogen source and concentrated sulfuric acid are mixed in a liquid environment, the molecular sieve, carbon source and nitrogen source are dispersed in the liquid environment in advance, and then the concentrated sulfuric acid is added and mixed, and then the mixture is independently incubated at 90-110 DEG C and 140-160 DEG C for 5-8 hours to obtain a composite precursor, the molecular sieve is MCM-48, and the carbon source comprises one of sucrose, glucose, starch and glucosamine hydrochloride; the composite precursor is calcined in nitrogen at 600-900 DEG C for 2 hours, and then etched in a sodium hydroxide solution at 70-90 DEG C to obtain a composite intermediate; the composite intermediate is calcined in ammonia at 600-900 DEG C for 2 hours and then cooled to obtain a carbon-based non-metallic catalyst.

2. The method of claim 1, wherein: The nitrogen source comprises one of urea and melamine; and / or, the mass ratio of the carbon source to the nitrogen source is 1:(0.1-2).

3. The production method according to claim 1 or 2, characterized by, The preparation method of the molecular sieve comprises: mixing and dissolving hexadecyl trimethyl sodium bromide and sodium hydroxide to obtain a mixed solution; adding a silicon source into the mixed solution to perform hydrothermal reaction, and then separating, drying and calcining to obtain the molecular sieve.

4. The method of claim 3, wherein: The silicon source comprises one of silica sol and tetraethyl orthosilicate; and / or, the mass ratio of the silicon source to the hexadecyl trimethyl sodium bromide is 1:(0.2-0.8); and / or, the mass ratio of the silicon source to the sodium hydroxide is 1:(0.02-0.1); and / or, the pH of the mixed solution is 12.5-14.

5. The method of claim 3, wherein: The silicon source is added into the mixed solution to perform hydrothermal reaction at 140-160 DEG C; and / or, the silicon source is added into the mixed solution to perform hydrothermal reaction for 20-28 hours; and / or, the molecular sieve is obtained by drying and calcining at 400-700 DEG C after separation; and / or, the molecular sieve is obtained by heating at a rate of 2-8 DEG C / min and then incubating and calcining.

6. The method of claim 1, wherein: The composite precursor is heated to 600-900 DEG C at a rate of 1-10 DEG C / min under a nitrogen atmosphere; and / or, the composite intermediate is heated to 600-900 DEG C at a rate of 1-10 DEG C / min under an ammonia atmosphere.

7. The method of claim 1, wherein: When etching in the sodium hydroxide solution at 70-90 DEG C, the concentration of the sodium hydroxide solution is 1-3 mol / L; and / or, etching in the sodium hydroxide solution for 10-14 hours; and / or, drying after etching in the sodium hydroxide solution.

8. A carbon-based non-metallic catalyst prepared by the preparation method of any one of claims 1 to 7.

9. Use of a carbon-based non-metallic catalyst prepared by the preparation method of any one of claims 1 to 7 in a fuel cell cathode.

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