CN113299932A - Co-N-C oxygen reduction catalyst and preparation method thereof - Google Patents
Co-N-C oxygen reduction catalyst and preparation method thereof Download PDFInfo
- Publication number
- CN113299932A CN113299932A CN202110497088.2A CN202110497088A CN113299932A CN 113299932 A CN113299932 A CN 113299932A CN 202110497088 A CN202110497088 A CN 202110497088A CN 113299932 A CN113299932 A CN 113299932A
- Authority
- CN
- China
- Prior art keywords
- catalyst
- cobalt
- mcm
- polypyrrole
- molecular sieve
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000003054 catalyst Substances 0.000 title claims abstract description 50
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 title abstract description 18
- 239000001301 oxygen Substances 0.000 title abstract description 18
- 229910052760 oxygen Inorganic materials 0.000 title abstract description 18
- 238000002360 preparation method Methods 0.000 title abstract description 11
- 230000009467 reduction Effects 0.000 title abstract description 11
- 238000010438 heat treatment Methods 0.000 claims abstract description 26
- 229920000128 polypyrrole Polymers 0.000 claims abstract description 23
- 239000002808 molecular sieve Substances 0.000 claims abstract description 20
- URGAHOPLAPQHLN-UHFFFAOYSA-N sodium aluminosilicate Chemical compound [Na+].[Al+3].[O-][Si]([O-])=O.[O-][Si]([O-])=O URGAHOPLAPQHLN-UHFFFAOYSA-N 0.000 claims abstract description 20
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical group [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 claims abstract description 15
- ROOXNKNUYICQNP-UHFFFAOYSA-N ammonium persulfate Chemical compound [NH4+].[NH4+].[O-]S(=O)(=O)OOS([O-])(=O)=O ROOXNKNUYICQNP-UHFFFAOYSA-N 0.000 claims description 19
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 claims description 16
- 238000000034 method Methods 0.000 claims description 15
- 229910017052 cobalt Inorganic materials 0.000 claims description 14
- 239000010941 cobalt Substances 0.000 claims description 14
- 150000001875 compounds Chemical group 0.000 claims description 12
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 10
- 238000001035 drying Methods 0.000 claims description 9
- 229910001870 ammonium persulfate Inorganic materials 0.000 claims description 8
- GVPFVAHMJGGAJG-UHFFFAOYSA-L cobalt dichloride Chemical compound [Cl-].[Cl-].[Co+2] GVPFVAHMJGGAJG-UHFFFAOYSA-L 0.000 claims description 8
- 239000012299 nitrogen atmosphere Substances 0.000 claims description 7
- 238000001291 vacuum drying Methods 0.000 claims description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 7
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 6
- 239000012153 distilled water Substances 0.000 claims description 6
- 238000005406 washing Methods 0.000 claims description 5
- 238000003756 stirring Methods 0.000 claims description 4
- 150000001868 cobalt Chemical class 0.000 claims description 3
- 238000004321 preservation Methods 0.000 claims description 3
- 238000002156 mixing Methods 0.000 claims description 2
- 238000004519 manufacturing process Methods 0.000 claims 1
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 abstract description 13
- 230000000694 effects Effects 0.000 abstract description 8
- 229910000510 noble metal Inorganic materials 0.000 abstract description 4
- 238000006243 chemical reaction Methods 0.000 abstract description 3
- QJGQUHMNIGDVPM-UHFFFAOYSA-N nitrogen group Chemical group [N] QJGQUHMNIGDVPM-UHFFFAOYSA-N 0.000 abstract description 3
- 239000002243 precursor Substances 0.000 abstract description 3
- 238000006555 catalytic reaction Methods 0.000 abstract description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 27
- 239000000523 sample Substances 0.000 description 17
- 230000003197 catalytic effect Effects 0.000 description 16
- 238000004502 linear sweep voltammetry Methods 0.000 description 14
- 229910052757 nitrogen Inorganic materials 0.000 description 13
- 238000002484 cyclic voltammetry Methods 0.000 description 11
- 238000006722 reduction reaction Methods 0.000 description 10
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 8
- 239000012298 atmosphere Substances 0.000 description 6
- 239000000446 fuel Substances 0.000 description 5
- 239000003792 electrolyte Substances 0.000 description 4
- 238000000227 grinding Methods 0.000 description 4
- 230000008569 process Effects 0.000 description 4
- 238000002791 soaking Methods 0.000 description 4
- 238000012360 testing method Methods 0.000 description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 3
- 229910052799 carbon Inorganic materials 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 239000000843 powder Substances 0.000 description 3
- 238000009210 therapy by ultrasound Methods 0.000 description 3
- 238000011282 treatment Methods 0.000 description 3
- 238000005303 weighing Methods 0.000 description 3
- 238000004458 analytical method Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 238000000354 decomposition reaction Methods 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 229910052697 platinum Inorganic materials 0.000 description 2
- 239000012488 sample solution Substances 0.000 description 2
- 238000004506 ultrasonic cleaning Methods 0.000 description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 150000004770 chalcogenides Chemical class 0.000 description 1
- 238000012512 characterization method Methods 0.000 description 1
- -1 cobalt chloride Chemical class 0.000 description 1
- 229910000428 cobalt oxide Inorganic materials 0.000 description 1
- IVMYJDGYRUAWML-UHFFFAOYSA-N cobalt(ii) oxide Chemical compound [Co]=O IVMYJDGYRUAWML-UHFFFAOYSA-N 0.000 description 1
- ZOMNIUBKTOKEHS-UHFFFAOYSA-L dimercury dichloride Chemical class Cl[Hg][Hg]Cl ZOMNIUBKTOKEHS-UHFFFAOYSA-L 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 238000003487 electrochemical reaction Methods 0.000 description 1
- UQSQSQZYBQSBJZ-UHFFFAOYSA-N fluorosulfonic acid Chemical compound OS(F)(=O)=O UQSQSQZYBQSBJZ-UHFFFAOYSA-N 0.000 description 1
- 238000009472 formulation Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 229910021397 glassy carbon Inorganic materials 0.000 description 1
- 239000005431 greenhouse gas Substances 0.000 description 1
- XLYOFNOQVPJJNP-ZSJDYOACSA-N heavy water Substances [2H]O[2H] XLYOFNOQVPJJNP-ZSJDYOACSA-N 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 230000008595 infiltration Effects 0.000 description 1
- 238000001764 infiltration Methods 0.000 description 1
- 239000003446 ligand Substances 0.000 description 1
- 150000002678 macrocyclic compounds Chemical class 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000000877 morphologic effect Effects 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 230000027756 respiratory electron transport chain Effects 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
- 229910052723 transition metal Inorganic materials 0.000 description 1
- 150000003624 transition metals Chemical class 0.000 description 1
- 238000010792 warming Methods 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
- H01M4/90—Selection of catalytic material
- H01M4/9041—Metals or alloys
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
- H01M4/88—Processes of manufacture
- H01M4/8825—Methods for deposition of the catalytic active composition
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
- H01M4/90—Selection of catalytic material
- H01M4/9075—Catalytic material supported on carriers, e.g. powder carriers
- H01M4/9083—Catalytic material supported on carriers, e.g. powder carriers on carbon or graphite
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/30—Hydrogen technology
- Y02E60/50—Fuel cells
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Materials Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Catalysts (AREA)
Abstract
The invention belongs to the field of electrochemical catalysis, and particularly relates to a Co-N-C oxygen reduction catalyst and a preparation method thereof. The specific technical scheme is as follows: polypyrrole is used as a nitrogen-containing precursor, a molecular sieve is used as a morphology confinement template, and the polypyrrole and cobalt salt form a complex which is subjected to heat treatment to form the catalyst. The invention provides a novel non-noble metal catalyst capable of replacing Pt/C: MCM-1 Co-/N/C-900. The catalyst has the advantages of simple preparation process, controllable reaction conditions, high activity and strong stability.
Description
Technical Field
The invention belongs to the field of electrochemical catalysis, and particularly relates to a Co-N-C oxygen reduction catalyst and a preparation method thereof.
Background
In order to deal with global warming, oil crisis and energy crisis, energy transformation in the future is mainly driven by the change from greenhouse gas emission reduction to targets. The hydrogen energy fuel cell automobile is considered to be one of the main development directions in the future due to the characteristics of high efficiency, zero emission and the like. The fuel cell is a device for converting chemical energy of fuel into electric energy, has high energy conversion efficiency, produces water, has little influence on the environment, and can be recycled, so the fuel cell is concerned. Most of the catalysts used in fuel cells are platinum (Pt) catalysts, but the reserves of Pt are very limited and expensive. Therefore, the search for non-noble metal catalysts that can replace Pt has been a hot point of research.
At present, non-noble metal catalysts are mainly classified into: metal macrocycles, nitrogen-doped transition metal on carbon (Me/N/C) catalysts, metal oxides, chalcogenides, and carbonitrides. Among them, the Me/N/C oxygen reduction catalyst is relatively easy to synthesize and has great development potential.
In catalysts such as Me/N/C, the role of the nitrogen element is critical. It is a bridge for connecting metal elements and carbon. However, in the heat treatment process of the Me/N/C catalyst, the decomposition rate of nitrogen element is very fast, the nitrogen element is very easy to lose, and even nitrogen and carbon doping cannot be carried out. Therefore, reducing nitrogen loss is a key to the preparation of such catalysts.
Disclosure of Invention
The invention aims to provide a Co-N-C oxygen reduction catalyst and a preparation method thereof.
In order to achieve the purpose of the invention, the technical scheme adopted by the invention is as follows: a catalyst, wherein a complex formed by polypyrrole and a cobalt-containing compound is confined in micropores of a molecular sieve.
Accordingly, a catalyst, the formulation of which comprises: polypyrrole, a cobalt-containing compound and a molecular sieve.
Preferably, the cobalt-containing compound is a cobalt salt.
Preferably, the molecular sieve is an MCM-41 molecular sieve.
Preferably, the formula comprises the following components in parts by weight: 1 part of polypyrrole, 1 part of a cobalt-containing compound and 1 part of a molecular sieve.
Correspondingly, the preparation method of the catalyst comprises the following steps:
(1) uniformly mixing polypyrrole, absolute ethyl alcohol, a cobalt-containing compound and a molecular sieve, adding ammonium persulfate into a beaker, fully stirring, and performing vacuum drying;
(2) carrying out heat treatment in the nitrogen atmosphere, wherein the heat preservation temperature of the heat treatment is 800-950 ℃.
Preferably, after the heat treatment is completed, the substrate is washed with hydrofluoric acid and distilled water, respectively, and dried.
Preferably, the cobalt-containing compound is cobalt chloride.
Preferably, the ammonium persulfate is used in an amount equal to that of the polypyrrole.
Preferably, the heat treatment method comprises the following steps: the temperature is increased from the room temperature to 800-950 ℃ at the speed of 10 ℃ per minute, then the temperature is kept at 800-950 ℃ for 2 hours, and then the temperature is reduced to the room temperature at 10 ℃ per minute.
The invention has the following beneficial effects: the invention provides a novel non-noble metal catalyst capable of replacing Pt: MCM-1 Co-/N/C-900. In the preparation of the catalyst, a nitrogen-containing precursor (polypyrrole) is limited by using a microporous structure of a molecular sieve MCM-41, so that nitrogen loss in heat treatment is avoided or reduced, the doping efficiency is effectively improved finally, and the activity and the stability of the catalyst are improved.
Drawings
FIG. 1 is a CV diagram of various Co/N/C catalysts with different Co doping ratios;
FIG. 2 is a LSV plot of various Co/N/C catalysts with different Co doping ratios;
FIG. 3 is a graph showing CV comparisons of Co/N/C and MCM-1 Co-/N/C-900;
FIG. 4 is a comparison of LSV for Co/N/C and MCM-1 Co-/N/C-900;
FIG. 5 is a graph showing CV comparison of MCM-1Co-/N/C-900 in a nitrogen atmosphere and an oxygen atmosphere, respectively;
FIG. 6 is a comparison of LSV of MCM-1Co-/N/C-900 in nitrogen and oxygen atmosphere, respectively;
FIG. 7 is a CV comparison graph of each MCM-1Co-N-C obtained at different heat treatment temperatures;
FIG. 8 is a comparison of LSV of each MCM-1Co-N-C obtained at different heat treatment temperatures;
FIG. 9 is the LSV curve of MCM-1-1Co/N/C-900 at different rotation speeds;
FIG. 10 is the K-L diagram of MCM-1 Co/N/C-900;
FIG. 11 is a LV contrast plot of MCM-1Co/N/C-900 after scanning for 0 and 500 cycles;
FIG. 12 is a comparison of LSV for MCM-1Co/N/C-900 after scanning for 0 and 500 cycles;
FIG. 13 is an electron microscope scanning morphology of MCM-1Co/N/C-900 shown in FIG. 1;
FIG. 14 is an electron microscope scanning morphology of MCM-1Co/N/C-900 shown in FIG. 2.
Detailed Description
The invention provides a novel oxygen reduction catalyst, and the catalyst formula comprises: polypyrrole, Co and molecular sieve, and the preferred scheme is as follows: the molecular sieve is an MCM-41 molecular sieve. More preferably, the Co is derived from a cobalt salt, such as cobalt chloride, and the mass ratio of the polypyrrole to the cobalt chloride is 1: 1; the more preferable scheme is as follows: polypyrrole: cobalt chloride: molecular sieve 1:1: 1.
The invention also provides a preparation method of the catalyst, which comprises the following steps:
1. weighing polypyrrole, absolute ethyl alcohol, cobalt chloride and an MCM-41 molecular sieve, stirring for 5 hours at room temperature, adding ammonium persulfate with the same quantity as the polypyrrole into a beaker, stirring for 24 hours, and transferring into a vacuum drying oven for drying.
2. And grinding the dried sample for 5 minutes, and then carrying out heat treatment to 800-950 ℃ by using a crucible resistance furnace under the nitrogen atmosphere. The specific method of the heat treatment comprises the following steps: the temperature is increased from the room temperature to 800-950 ℃ at the speed of 10 ℃ per minute, then the temperature is kept at 800-950 ℃ for 2 hours, and then the temperature is reduced to the room temperature at 10 ℃ per minute. The preferred heat treatment temperature is 900 ℃.
3. The sample was taken out, ground to a fine powder, washed with hydrofluoric acid: soaking in 40% hydrofluoric acid for 10 min, ultrasonic cleaning with ultrasonic cleaner for 30 min, and centrifuging with centrifuge. The mixture was washed 3 times with a hydrofluoric acid solution, 1 time with distilled water, and finally, transferred to a vacuum drying oven for drying in the same manner as described above.
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art.
The first embodiment is as follows: preparation of oxygen reduction catalyst
1. Preparing the N/C catalyst. 0.2g of polypyrrole (PPY) and 0.2g of ammonium persulfate (NH) were weighed4)S2O810mL of absolute ethanol was stirred in a 50mL beaker at room temperature for 24 hours, and then transferred to a vacuum drying oven for drying.
The dried sample was ground in an agate pot for 5 minutes, and then heat-treated in a crucible resistance furnace filled with nitrogen. The heat treatment specifically comprises the following steps: the temperature is increased from the room temperature to 900 ℃ at the speed of 10 ℃ per minute, then the temperature is kept at 900 ℃ for 2h, and then the temperature is reduced to the room temperature at 10 ℃ per minute. After the heat treatment was completed, the sample was taken out, ground again to a powder state, and then put into a sample tube.
Subsequently, hydrochloric acid washing was carried out: pouring 0.2mol/L hydrochloric acid solution into 2/3 position of the sample tube, completely soaking the sample in the hydrochloric acid solution, soaking for 10 minutes, performing ultrasonic treatment at 40KHZ frequency for 30 minutes by using an ultrasonic cleaning machine, centrifuging for 3 minutes by using a TG-16S type centrifuge, and removing the surface solution. The washing with 0.1M hydrochloric acid solution was repeated 3 times and 1 time with distilled water. Finally, the mixture is moved into a vacuum drying oven for drying. Thus obtaining the N/C catalyst.
2. Preparing Co/N/C catalyst. Setting 3 treatments, and respectively weighing each treatment: 0.2g of polypyrrole, 0.2g of ammonium persulfate (NH)4)S2O810mL of absolute ethanol. The 3 treatments were placed in 3 clean 50mL beakers, and 0.1g, 0.2g, 0.4g cobalt chloride was added, labeled: 0.5Co/N/C, 1Co/N/C, 2 Co/N/C. Then according to the mode of step 1Stirring, drying, grinding, heat treatment, grinding, washing and drying to obtain 3 groups of Co/N/C catalysts. Wherein the heat treatment is performed in an atmosphere filled with nitrogen gas.
3. Preparing MCM-1Co/N/C catalyst. 0.2g of polypyrrole, 10mL of absolute ethanol, 0.2g of cobalt chloride and 0.2g of MCM-41 molecular sieve are weighed and placed in a clean 50mL small beaker. Stirred at room temperature for 5h, and then 0.2g of ammonium persulfate (NH) was added to the beaker4)S2O8And then stirred for 24 hours, and then transferred into a vacuum drying oven for drying. The dried sample was ground with an agate bowl for 5 minutes and then heat-treated to 900 ℃ with a crucible resistance furnace under an atmosphere of nitrogen. The specific method of heat treatment is the same as that of step 1. Then taking out the sample, grinding into powder and putting into a sample tube. And then using hydrofluoric acid for washing: pouring 40% hydrofluoric acid into 2/3 part of the sample tube, soaking for 10 min, performing ultrasonic treatment at 40KHZ frequency for 30 min by using an ultrasonic cleaner, centrifuging for 3 min by using a TG-16S type centrifuge, and pouring off the surface solution after separation. The obtained product was washed 3 times with hydrofluoric acid solution, 1 time with distilled water, and finally dried in a vacuum oven.
MCM-1Co/N/C-800, MCM-1Co/N/C-900 and MCM-1Co/N/C-9503 temperature series samples are prepared and obtained by the same method; the heat preservation temperature of the heat treatment is 800 ℃, 900 ℃ and 950 ℃, and the rest conditions are the same.
Example two: activity display and morphology characterization of procatalyst
1. And (5) displaying the catalytic activity. The method for testing the catalytic activity in the embodiment is as follows: weighing a sample to be detected 1 mg in a small sample tube, adding 90 mu L of distilled water and 10 mu L of Lnafion solution (perfluorosulfonic acid polymer solution) by using a pipette, performing ultrasonic treatment for 10 minutes, then transferring 10 mu L of sample solution by using the pipette, dripping the sample solution on an electrode, and naturally drying at room temperature to prepare the thin film electrode loaded with the sample to be detected. The instrument used for the test is CHI760E electrochemical workstation produced by Shanghai Chenghua instruments, Inc., a three-electrode system (a reference electrode is a saturated calomel electrode, a counter electrode is a platinum sheet electrode, and a working electrode is a glassy carbon electrode loaded with a sample catalyst) is used, and after a test device is arranged, Cyclic Voltammetry (CV) and Linear Sweep Voltammetry (LSV) are used for testing.
Cyclic Voltammetry (CV): potential range (-0.8V-0.2V, scan rate (5 mV/s)), electrolyte (0.1 mol/L KOH solution filled with oxygen). Linear Sweep Voltammetry (LSV). The potential range (-0.8V-0.2V), scan rate (5mV/s), standing time (60s), electrolyte (0.1 mol/L KOH solution filled with oxygen), and rotation speed 1600 rpm.
(1) Effect of Co doping ratio on Co/N/C catalytic Activity
The initial potential of Pt is about 1V, the half-wave potential is about 0.86V, and the closer the initial potential and the half-wave potential are to the corresponding values of Pt, the better. CV and LSV contrast plots of different ratios of Co doping are shown in fig. 1 and 2, respectively.
It can be seen that the 1Co/N/C initial potential is 0.87V, the half-wave potential is 0.82V, and is closest to Pt; the current density of 1Co/N/C is also significantly higher than 0.5Co/N/C and 2 Co/N/C. And the oxygen reduction peak of 2Co/N/C is not obvious, which is probably because a large amount of elemental cobalt or cobalt oxide covers the catalytic active sites of the catalyst, resulting in poor catalytic performance. Too little cobalt is difficult to form a Co/N/C structure. It follows that 1Co/N/C has the best catalytic effect.
(2) Effect of MCM-41 restriction regulation on Co/N/C catalytic activity
FIGS. 3 and 4 are CV and LSV comparison plots for Co/N/C and MCM-1Co-/N/C-900, respectively. It can be seen that the MCM-1Co/N/C-900 has an initial potential of 0.91V and a half-wave potential of 0.85V, which is higher than that of the sample of 1 Co/N/C; the limit current density of MCM-1Co/N/C-900 is also improved to a great extent. This may be because: MCM-41 plays a role of space confinement, effectively regulates and controls the loss speed of a nitrogen-containing precursor (polypyrrole) in the heat treatment process, and reduces the decomposition loss rate of nitrogen, thereby improving the nitrogen doping efficiency and improving the oxygen reduction catalytic performance.
(3) Effect of different gas atmospheres on catalytic activity of MCM-1Co/N/C-900
FIGS. 5 and 6 are CV comparison and LSV comparison of MCM-1Co-/N/C-900 in nitrogen and oxygen atmosphere, respectively. Wherein, the nitrogen atmosphere is that the electrolyte is changed from the KOH solution of 0.1mol/L filled with oxygen to the KOH solution filled with nitrogen, and the rest is unchanged. It can be seen that MCM-1Co/N/C-900 has almost no catalytic performance in nitrogen atmosphere, which indicates that the catalyst has no electrocatalytic activity in nitrogen atmosphere and good catalytic activity in oxygen atmosphere.
(4) Effect of different Heat treatment temperatures on the catalytic Activity of MCM-1Co-N-C
FIGS. 7 and 8 are CV comparison and LSV comparison of each MCM-1Co-N-C obtained at different heat treatment temperatures, respectively. It can be seen that: although the initial potential of MCM-1Co/N/C-950 is slightly higher than that of MCM-1Co/N/C-900, the electrochemical reaction kinetics is slower than that of the MCM-1Co/N/C-900 sample (the slope of the peak is lower); and the limit current density of the MCM-1Co/N/C-900 is obviously higher than that of the MCM-1Co/N/C-800 and the MCM-1 Co/N/C-950. Therefore, the heat treatment temperature has a great influence on the formation of Co/N/C domains, and the formation of ligands is not favored when the temperature is too high or too low, and the catalytic activity of the catalyst obtained at 900 ℃ is optimal.
(6) MCM-1Co/N/C-900 electrode kinetic characteristic analysis
The electrode dynamics of MCM-1-1Co/N/C-900 were tested using a rotating disk electrode. The LSV curves of MCM-1-1Co/N/C-900 at different rotation speeds (400 rpm-2500 rpm) are shown in FIG. 9. The faster the speed, the greater the limiting current density, but no change in the initial potential.
The K-L diagram of MCM-1Co/N/C-900 is shown in FIG. 10. Calculated by the formula K-L, the average number of transferred electrons is 3.89, which is very close to a 4-electron reaction model. That is, the MCM-1Co/N/C-900 catalytic process is mainly a kinetic process (O) of 4 electron transfer2+4H++4e-→2H2O). The MCM-1Co/N/C-900 catalyst can be used for electrocatalytic oxygen reduction reaction in an alkaline medium, and is hopeful to be a substitute of a commercial Pt catalyst.
(7) Stability analysis of MCM-1Co/N/C-900
After scanning 0 and 500 circles, the CV and LSV contrast plots of MCM-1Co/N/C-900 are shown in FIGS. 11 and 12, respectively. As can be seen, after 500 scanning cycles, the initial potential and the peak potential of the MCM-1Co/N/C-900 are not obviously changed, and the limiting current density is slightly reduced. The result shows that the stability of the catalytic performance of the MCM-1Co/N/C-900 is excellent.
2. The MCM-1Co/N/C-900 is subjected to electron microscope scanning, and the morphological characteristics are shown in FIGS. 13(100nm) and 14(20 nm). The apparent porous structure is visible in the figure. The porous structure can provide a larger attachment area for the active component, and is beneficial to the infiltration of electrolyte and electron transfer, thereby improving the catalytic activity.
The above-described embodiments are merely illustrative of the preferred embodiments of the present invention, and do not limit the scope of the present invention, and various changes, modifications, alterations, and substitutions which may be made by those skilled in the art without departing from the spirit of the present invention shall fall within the protection scope defined by the claims of the present invention.
Claims (10)
1. A catalyst, characterized by: polypyrrole and cobalt-containing compounds form complexes in micropores of the molecular sieve confinement.
2. A catalyst, characterized by: the formula comprises the following components: polypyrrole, a cobalt-containing compound and a molecular sieve.
3. The catalyst of claim 2, wherein: the cobalt-containing compound is a cobalt salt.
4. The catalyst of claim 2, wherein: the molecular sieve is an MCM-41 molecular sieve.
5. The catalyst of claim 2, wherein: the formula comprises the following components in parts by weight: 1 part of polypyrrole, 1 part of a cobalt-containing compound and 1 part of a molecular sieve.
6. A process for preparing a catalyst according to any one of claims 1 to 5, characterized in that: the method comprises the following steps:
(1) uniformly mixing polypyrrole, absolute ethyl alcohol, a cobalt-containing compound and a molecular sieve, adding ammonium persulfate into a beaker, fully stirring, and performing vacuum drying;
(2) carrying out heat treatment in the nitrogen atmosphere, wherein the heat preservation temperature of the heat treatment is 800-950 ℃.
7. The method for preparing the catalyst according to claim 6, wherein: and after the heat treatment is finished, respectively washing by using hydrofluoric acid and distilled water, and drying.
8. The method for preparing the catalyst according to claim 6, wherein: the cobalt-containing compound is cobalt chloride.
9. The method for preparing the catalyst according to claim 6, wherein: the dosage of the ammonium persulfate is equal to that of the polypyrrole.
10. The method for preparing the catalyst according to claim 6, wherein: the heat treatment method comprises the following steps: the temperature is increased from the room temperature to 800-950 ℃ at the speed of 10 ℃ per minute, then the temperature is kept at 800-950 ℃ for 2 hours, and then the temperature is reduced to the room temperature at 10 ℃ per minute.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110497088.2A CN113299932A (en) | 2021-05-07 | 2021-05-07 | Co-N-C oxygen reduction catalyst and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110497088.2A CN113299932A (en) | 2021-05-07 | 2021-05-07 | Co-N-C oxygen reduction catalyst and preparation method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113299932A true CN113299932A (en) | 2021-08-24 |
Family
ID=77321014
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110497088.2A Pending CN113299932A (en) | 2021-05-07 | 2021-05-07 | Co-N-C oxygen reduction catalyst and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113299932A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115207378A (en) * | 2022-07-25 | 2022-10-18 | 陕西科技大学 | Polypyrrole nanotube electrocatalyst and preparation method and application thereof |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102614915A (en) * | 2012-02-22 | 2012-08-01 | 华东理工大学 | Preparation method for base metal oxygen reduction catalyst |
| US20130084474A1 (en) * | 2010-03-18 | 2013-04-04 | Randell L. Mills | Electrochemical hydrogen-catalyst power system |
| CN110639481A (en) * | 2019-09-20 | 2020-01-03 | 桂林理工大学 | Method for preparing polypyrrole and mesoporous molecular sieve composite material |
-
2021
- 2021-05-07 CN CN202110497088.2A patent/CN113299932A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20130084474A1 (en) * | 2010-03-18 | 2013-04-04 | Randell L. Mills | Electrochemical hydrogen-catalyst power system |
| CN102614915A (en) * | 2012-02-22 | 2012-08-01 | 华东理工大学 | Preparation method for base metal oxygen reduction catalyst |
| CN110639481A (en) * | 2019-09-20 | 2020-01-03 | 桂林理工大学 | Method for preparing polypyrrole and mesoporous molecular sieve composite material |
Non-Patent Citations (1)
| Title |
|---|
| YAO LIU ET AL: "A Cheap Polypyrrole-Derived Fe-N-C Electrocatalyst with Ultrahigh Oxygen Reduction Activity in Alkaline Electrolyte", 《INTERNATIONAL JOURNAL OF ELECTROCHEMICAL SCIENCE》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115207378A (en) * | 2022-07-25 | 2022-10-18 | 陕西科技大学 | Polypyrrole nanotube electrocatalyst and preparation method and application thereof |
| CN115207378B (en) * | 2022-07-25 | 2023-09-05 | 陕西科技大学 | Polypyrrole nanotube electrocatalyst and preparation method and application thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110911697B (en) | Transition metal/nitrogen-doped porous carbon nanosphere electrocatalyst and preparation method thereof | |
| CN113270595B (en) | Nitrogen-doped carbon-supported non-noble metal nano catalyst prepared based on MOF | |
| CN107887613B (en) | Oxygen reduction electrode based on three-dimensional net-shaped nitrogen, phosphorus and sulfur co-doped porous carbon material, and preparation method and application thereof | |
| CN109019602A (en) | Be carbonized molybdenum material, molybdenum carbide vulcanization molybdenum composite material and preparation method and application | |
| CN110721713B (en) | Mo 2 C catalytic material and preparation method and application thereof | |
| CN108336374B (en) | High-performance ternary Fe-Co-Ni Co-doped nitrogen-containing carbon material and preparation method and application thereof | |
| CN109852994A (en) | A kind of Co9S8With the preparation method of nitrogen-doped carbon composite array electrode | |
| CN113659155B (en) | Metal-nitrogen-carbon coated carbon nanocage electrocatalyst and preparation method and application thereof | |
| CN106876729A (en) | Ordered mesopore carbon grows the preparation and catalyst and application of carbon nano-tube catalyst | |
| CN112652780B (en) | Fe/Fe 3 Preparation method of C nano-particle loaded porous nitrogen-doped carbon-based oxygen reduction catalyst | |
| CN113881965B (en) | Metal nanoparticle supported catalyst with biomass carbon source as template and preparation method and application thereof | |
| CN108091892A (en) | A kind of Fe/Co/N/MWCNTs catalyst | |
| CN102916203A (en) | Cathode non-platinum catalyst of proton exchange membrane fuel cell and preparation method thereof | |
| CN110504456A (en) | It is a kind of based on nitrogen oxygen doping ball/piece porous carbon materials oxygen reduction electrode and its preparation method and application | |
| CN108649237B (en) | Gel pyrolysis-based cobalt-nitrogen doped carbon composite material and preparation method and application thereof | |
| CN114351185B (en) | Dual-function electrocatalyst with heterostructure nickel cobalt nitride nanosheet array and preparation and application thereof | |
| CN113410473B (en) | Iron-nickel polyphenol network nano composite carbon material electrocatalyst based on chitosan modified cellulose aerogel and preparation method thereof | |
| CN113299932A (en) | Co-N-C oxygen reduction catalyst and preparation method thereof | |
| CN112002909B (en) | Preparation method of Zn-Cu-N-based co-doped carbon composite material | |
| CN112553643B (en) | Nitrogen-doped carbon-coated non-noble bimetallic cobalt-molybdenum oxide oxygen evolution reaction catalyst, preparation method and application | |
| CN109546157A (en) | A kind of preparation method of copper, cobalt nitride and carbon In-situ reaction electrode | |
| CN113659154A (en) | Carbon catalyst for cathode of alkaline fuel cell and preparation method thereof | |
| CN113629260A (en) | Cobalt and nitrogen co-doped carbon nanosheet material and preparation and application thereof | |
| CN112853377A (en) | Preparation method and application of bifunctional metal-free nitrogen-doped carbon catalyst | |
| CN112675897B (en) | Preparation method of asphalt-based oxygen reduction electrocatalyst |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20210824 |
|
| RJ01 | Rejection of invention patent application after publication |