CN114836770B - Cobalt-based catalytic electrode for electrocatalytic reduction of nitrate radical into ammonia and preparation method thereof - Google Patents
Cobalt-based catalytic electrode for electrocatalytic reduction of nitrate radical into ammonia and preparation method thereof Download PDFInfo
- Publication number
- CN114836770B CN114836770B CN202210702566.3A CN202210702566A CN114836770B CN 114836770 B CN114836770 B CN 114836770B CN 202210702566 A CN202210702566 A CN 202210702566A CN 114836770 B CN114836770 B CN 114836770B
- Authority
- CN
- China
- Prior art keywords
- electrode
- cobalt
- nitrate
- ammonia
- precursor
- 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.)
- Active
Links
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 title claims abstract description 72
- 230000003197 catalytic effect Effects 0.000 title claims abstract description 41
- 229910017052 cobalt Inorganic materials 0.000 title claims abstract description 40
- 239000010941 cobalt Substances 0.000 title claims abstract description 40
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 title claims abstract description 40
- 229910021529 ammonia Inorganic materials 0.000 title claims abstract description 36
- 238000002360 preparation method Methods 0.000 title claims abstract description 12
- 230000009467 reduction Effects 0.000 title claims description 27
- YPJKMVATUPSWOH-UHFFFAOYSA-N nitrooxidanyl Chemical compound [O][N+]([O-])=O YPJKMVATUPSWOH-UHFFFAOYSA-N 0.000 title abstract description 7
- 229910002651 NO3 Inorganic materials 0.000 claims abstract description 36
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 claims abstract description 36
- 239000002243 precursor Substances 0.000 claims description 32
- WCUXLLCKKVVCTQ-UHFFFAOYSA-M Potassium chloride Chemical compound [Cl-].[K+] WCUXLLCKKVVCTQ-UHFFFAOYSA-M 0.000 claims description 16
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 15
- 229910052799 carbon Inorganic materials 0.000 claims description 12
- 239000002244 precipitate Substances 0.000 claims description 12
- 101001018064 Homo sapiens Lysosomal-trafficking regulator Proteins 0.000 claims description 11
- 102100033472 Lysosomal-trafficking regulator Human genes 0.000 claims description 11
- 235000010703 Modiola caroliniana Nutrition 0.000 claims description 11
- 244000038561 Modiola caroliniana Species 0.000 claims description 11
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 10
- 238000006243 chemical reaction Methods 0.000 claims description 10
- 229910021392 nanocarbon Inorganic materials 0.000 claims description 10
- 239000002245 particle Substances 0.000 claims description 10
- 229910021607 Silver chloride Inorganic materials 0.000 claims description 9
- 239000006260 foam Substances 0.000 claims description 9
- 238000000034 method Methods 0.000 claims description 9
- 229920006395 saturated elastomer Polymers 0.000 claims description 9
- HKZLPVFGJNLROG-UHFFFAOYSA-M silver monochloride Chemical compound [Cl-].[Ag+] HKZLPVFGJNLROG-UHFFFAOYSA-M 0.000 claims description 9
- -1 polytetrafluoroethylene Polymers 0.000 claims description 8
- 239000001103 potassium chloride Substances 0.000 claims description 8
- 235000011164 potassium chloride Nutrition 0.000 claims description 8
- 239000000758 substrate Substances 0.000 claims description 8
- 239000000203 mixture Substances 0.000 claims description 7
- 239000002135 nanosheet Substances 0.000 claims description 7
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims description 6
- 239000010949 copper Substances 0.000 claims description 6
- 238000001035 drying Methods 0.000 claims description 6
- 239000010936 titanium Substances 0.000 claims description 6
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 5
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 5
- 239000011230 binding agent Substances 0.000 claims description 5
- 239000011248 coating agent Substances 0.000 claims description 5
- 238000000576 coating method Methods 0.000 claims description 5
- 229910052802 copper Inorganic materials 0.000 claims description 5
- 238000001914 filtration Methods 0.000 claims description 5
- 238000011068 loading method Methods 0.000 claims description 5
- 238000002156 mixing Methods 0.000 claims description 5
- 229910052759 nickel Inorganic materials 0.000 claims description 5
- 238000003756 stirring Methods 0.000 claims description 5
- 229910052719 titanium Inorganic materials 0.000 claims description 5
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 4
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 4
- 229910002804 graphite Inorganic materials 0.000 claims description 4
- 239000010439 graphite Substances 0.000 claims description 4
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims description 4
- 239000002033 PVDF binder Substances 0.000 claims description 3
- 239000003570 air Substances 0.000 claims description 3
- 230000001680 brushing effect Effects 0.000 claims description 3
- 238000005516 engineering process Methods 0.000 claims description 3
- UQSQSQZYBQSBJZ-UHFFFAOYSA-N fluorosulfonic acid Chemical compound OS(F)(=O)=O UQSQSQZYBQSBJZ-UHFFFAOYSA-N 0.000 claims description 3
- 229910052734 helium Inorganic materials 0.000 claims description 3
- 239000001307 helium Substances 0.000 claims description 3
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 claims description 3
- 238000000265 homogenisation Methods 0.000 claims description 3
- 229920001343 polytetrafluoroethylene Polymers 0.000 claims description 3
- 239000004810 polytetrafluoroethylene Substances 0.000 claims description 3
- 229920002981 polyvinylidene fluoride Polymers 0.000 claims description 3
- 238000004064 recycling Methods 0.000 claims description 3
- 229920005989 resin Polymers 0.000 claims description 3
- 239000011347 resin Substances 0.000 claims description 3
- 238000005507 spraying Methods 0.000 claims description 3
- KJTLSVCANCCWHF-UHFFFAOYSA-N Ruthenium Chemical compound [Ru] KJTLSVCANCCWHF-UHFFFAOYSA-N 0.000 claims description 2
- 229910052786 argon Inorganic materials 0.000 claims description 2
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 claims description 2
- 229910052737 gold Inorganic materials 0.000 claims description 2
- 239000010931 gold Substances 0.000 claims description 2
- 239000000463 material Substances 0.000 claims description 2
- 229910052751 metal Inorganic materials 0.000 claims description 2
- 239000002184 metal Substances 0.000 claims description 2
- 229910052757 nitrogen Inorganic materials 0.000 claims description 2
- 229910052697 platinum Inorganic materials 0.000 claims description 2
- 229910052707 ruthenium Inorganic materials 0.000 claims description 2
- 238000004544 sputter deposition Methods 0.000 claims description 2
- 239000011521 glass Substances 0.000 claims 1
- 150000002739 metals Chemical class 0.000 claims 1
- 238000006722 reduction reaction Methods 0.000 abstract description 22
- 239000000243 solution Substances 0.000 description 6
- 239000000725 suspension Substances 0.000 description 6
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 description 5
- 239000003054 catalyst Substances 0.000 description 5
- 239000003792 electrolyte Substances 0.000 description 5
- 238000000197 pyrolysis Methods 0.000 description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 5
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 description 4
- 239000008367 deionised water Substances 0.000 description 4
- 229910021641 deionized water Inorganic materials 0.000 description 4
- 239000011259 mixed solution Substances 0.000 description 4
- VWDWKYIASSYTQR-UHFFFAOYSA-N sodium nitrate Chemical compound [Na+].[O-][N+]([O-])=O VWDWKYIASSYTQR-UHFFFAOYSA-N 0.000 description 4
- IOVCWXUNBOPUCH-UHFFFAOYSA-M Nitrite anion Chemical compound [O-]N=O IOVCWXUNBOPUCH-UHFFFAOYSA-M 0.000 description 3
- MUBZPKHOEPUJKR-UHFFFAOYSA-N Oxalic acid Chemical compound OC(=O)C(O)=O MUBZPKHOEPUJKR-UHFFFAOYSA-N 0.000 description 3
- HJPBEXZMTWFZHY-UHFFFAOYSA-N [Ti].[Ru].[Ir] Chemical compound [Ti].[Ru].[Ir] HJPBEXZMTWFZHY-UHFFFAOYSA-N 0.000 description 3
- 239000012298 atmosphere Substances 0.000 description 3
- 238000004140 cleaning Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 229910052709 silver Inorganic materials 0.000 description 3
- 239000004332 silver Substances 0.000 description 3
- 229920008712 Copo Polymers 0.000 description 2
- PMZURENOXWZQFD-UHFFFAOYSA-L Sodium Sulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=O PMZURENOXWZQFD-UHFFFAOYSA-L 0.000 description 2
- 238000007792 addition Methods 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000001351 cycling effect Effects 0.000 description 2
- 238000010828 elution Methods 0.000 description 2
- 235000011187 glycerol Nutrition 0.000 description 2
- 229910021389 graphene Inorganic materials 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000013507 mapping Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 238000000643 oven drying Methods 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 238000001878 scanning electron micrograph Methods 0.000 description 2
- 235000010344 sodium nitrate Nutrition 0.000 description 2
- 239000004317 sodium nitrate Substances 0.000 description 2
- 229910052938 sodium sulfate Inorganic materials 0.000 description 2
- 235000011152 sodium sulphate Nutrition 0.000 description 2
- 238000002798 spectrophotometry method Methods 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 230000009471 action Effects 0.000 description 1
- 239000011149 active material Substances 0.000 description 1
- 238000005054 agglomeration Methods 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000006356 dehydrogenation reaction Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 229910021397 glassy carbon Inorganic materials 0.000 description 1
- 230000036541 health Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000011065 in-situ storage Methods 0.000 description 1
- 238000001095 inductively coupled plasma mass spectrometry Methods 0.000 description 1
- 238000002386 leaching Methods 0.000 description 1
- 239000002070 nanowire Substances 0.000 description 1
- 239000012299 nitrogen atmosphere Substances 0.000 description 1
- 235000006408 oxalic acid Nutrition 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 230000002194 synthesizing effect Effects 0.000 description 1
- 238000009210 therapy by ultrasound Methods 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 239000002351 wastewater Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B1/00—Electrolytic production of inorganic compounds or non-metals
- C25B1/01—Products
- C25B1/27—Ammonia
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B11/00—Electrodes; Manufacture thereof not otherwise provided for
- C25B11/04—Electrodes; Manufacture thereof not otherwise provided for characterised by the material
- C25B11/051—Electrodes formed of electrocatalysts on a substrate or carrier
- C25B11/052—Electrodes comprising one or more electrocatalytic coatings on a substrate
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B11/00—Electrodes; Manufacture thereof not otherwise provided for
- C25B11/04—Electrodes; Manufacture thereof not otherwise provided for characterised by the material
- C25B11/051—Electrodes formed of electrocatalysts on a substrate or carrier
- C25B11/073—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material
- C25B11/091—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material consisting of at least one catalytic element and at least one catalytic compound; consisting of two or more catalytic elements or catalytic compounds
-
- 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
- Y02E60/36—Hydrogen production from non-carbon containing sources, e.g. by water electrolysis
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Electrodes For Compound Or Non-Metal Manufacture (AREA)
- Catalysts (AREA)
Abstract
The invention discloses a cobalt-based catalytic electrode for electrocatalytically reducing nitrate radical into ammonia and a preparation method thereof. The catalytic electrode provided by the invention has excellent nitrate removal rate, ammonia generation rate and cycle stability in the electrocatalytic nitrate reduction reaction.
Description
Technical Field
The invention belongs to the field of catalyst preparation, and particularly relates to a cobalt-based catalytic electrode for nitrate radical reduction and a preparation method thereof.
Background
With the rapid development of industrialization, agriculture and town, a large amount of high-concentration nitrate waste water is generated, which can pose a great threat to the ecological environment and human health if not properly treated. In recent years, the reduction of nitrate into ammonia by using an electrocatalytic technology uses green electrons as a reducing agent, and the advantages of mild operating conditions, strong controllability and the like are receiving attention.
Electrocatalytic nitrate reduction is a complex multi-electron multi-proton transfer process, and the catalytic electrode significantly affects the conversion rate, the product selectivity and the catalytic stability. At present, a related technology for synthesizing a catalytic electrode for electrocatalytic reduction of nitrate into ammonia has been reported, and patent CN 105198046 discloses a Ti-graphene catalytic electrode which is prepared by assistance of graphene oxide, wherein when the initial nitrate concentration is 50 mg N/L, the removal rate of reaction 1 h is 41.8%, and the removal efficiency of nitrate is low; patent CN 114369841 discloses a cobalt nanowire electrode prepared by in-situ growth by using foamed cobalt and oxalic acid as raw materials, which is used for preparing ammonia by electrocatalytic reduction of nitrate, the reaction is 6 h, the nitrate removal rate is 84.1%, the ammonia generation rate is 77.7%, and the deep removal of nitrate and the efficient directional conversion of ammonia cannot be realized; patent CN 112206797 discloses a copper and Ti based alloy 3 C 2 T x Cu (I) @ Ti prepared by taking MXene as raw material 3 C 2 T x The catalyst of MXene (R),6 h converts 77.1% of nitrate into ammonia, and the ammonia conversion rate gradually decreases with the increase of the recycling times of the electrode, which seriously affects the further practical application of the catalyst.
Disclosure of Invention
The invention aims to provide a cobalt-based catalytic electrode with excellent nitrate removal effect, ammonia generation rate and cycle stability and a preparation method thereof, which are used for efficiently electrocatalytically reducing nitrate to ammonia.
According to a first aspect of the present invention there is provided a method of preparing a cobalt-based catalytic electrode for electrocatalytic reduction of nitrate to ammonia, comprising the steps of:
step one: NH is added to 4 Cl、CoCl 2 ·6H 2 O、NH 4 H 2 PO 4 And NH 3 ·H 2 Mixing the four solutions, fully stirring, filtering, and drying to obtain a mauve precipitate;
step two: pyrolyzing the mauve precipitate obtained in the first step to obtain a blue precursor;
step three: mixing the precursor obtained in the second step with nano carbon particles, adding the mixture into an alcohol solution containing a binder, and coating the mixture on an electrode substrate to prepare a precursor electrode after ultrasonic homogenization;
step four: and (3) treating the precursor electrode prepared in the step (III) under a reduction potential to obtain the cobalt-based catalytic electrode.
Preferably, the pyrolysis atmosphere in the second step is one or a mixture of more of air, argon, helium and nitrogen, the pyrolysis temperature is 250-550 ℃, and the pyrolysis time is 0.5-5 hours.
Preferably, in the step three, the mass ratio of the precursor to the nano carbon particles is 1:10-1:0, the binder is one or a combination of more of perfluorosulfonic acid resin, polytetrafluoroethylene and polyvinylidene fluoride, and the loading capacity of the precursor is 0.1-5 mg/cm 2 。
Preferably, in the third step, the electrode substrate is one of foam nickel, foam titanium, foam copper, foam cobalt, nickel net, titanium net, copper net, cobalt net, carbon paper, carbon felt and glassy carbon; the coating technique is one of dripping, spraying, sputtering and brushing.
Preferably, in the fourth step, the reduction potential is-1 to-2V (relative to a saturated Ag/AgCl reference electrode) and the treatment time is 10-120 min.
Preferably, in the fourth step, a three-electrode system is used, wherein the counter electrode is one or a combination electrode of more than one metal of a graphite carbon rod electrode, a platinum electrode, a gold electrode, a ruthenium electrode and a titanium electrode, and the distance between the counter electrode and the working electrode is 0.5-10 cm.
According to a second aspect of the invention, the invention provides a cobalt-based catalytic electrode for electrocatalytically reducing nitrate to ammonia, wherein a cobalt-based material on the electrode is in an ultrathin nano sheet shape, and the average thickness is 2-15 nm;
preferably, the electrode has nitrate conversion rate of more than or equal to 99% and ammonia generation rate of more than or equal to 98%, and the recycling frequency is more than or equal to 8 times.
Compared with the prior art, the invention has the beneficial effects that:
(1) The catalytic electrode obtained by the preparation method provided by the invention has the advantages that the catalytic active material is cobalt-based ultrathin nanosheets, has higher specific surface area, can expose abundant high-activity sites, and is beneficial to efficiently catalyzing nitrate radical reduction reaction;
(2) The catalytic electrode provided by the invention can effectively realize electrocatalytic reduction of nitrate into ammonia under normal temperature and normal pressure, and has excellent nitrate removal rate (higher than 99%) and ammonia generation rate (higher than 98%);
(3) The catalytic electrode provided by the invention has excellent cycling stability, the leaching amount of cobalt after the reaction is over is lower than 30 mug/L, and the nitrate radical removal rate is still higher than 99% and the ammonia generation rate is higher than 96% after 8 times of cycling tests.
Drawings
Fig. 1 is a flow chart of the preparation of a cobalt-based catalytic electrode.
Fig. 2 is an SEM image of the precursor electrode prepared in example 2.
Fig. 3 is an SEM image of the cobalt-based catalytic electrode prepared in example 2.
FIG. 4 is a mapping graph of HAADF and Co, C for the cobalt-based catalytic electrode prepared in example 2.
Fig. 5 is a graph of the cycle stability of the electrocatalytic reduction of nitrate to ammonia using the cobalt-based catalytic electrode provided in example 5.
Fig. 6 is a graph showing the elution amount of Co after completion of the electrocatalytic reduction of nitrate to ammonia by the cobalt-based catalyst electrode provided in example 5.
Detailed Description
In order that the above-recited objects, features and advantages of the present invention will become more readily apparent, a more particular description of the invention briefly described above will be rendered by reference to the appended drawings. The following is merely illustrative and explanatory of the principles of the invention, as various modifications and additions may be made to the specific embodiments described, or similar arrangements may be substituted by those skilled in the art, without departing from the principles of the invention or beyond the scope of the invention as defined in the appended claims.
As shown in fig. 1, the preparation method of the cobalt-based catalytic electrode for electrocatalytic reduction of nitrate to ammonia provided by the invention comprises the following preparation steps:
step one: preparation of NH 4 Cl、CoCl 2 ·6H 2 O、NH 4 H 2 PO 4 、NH 3 ·H 2 O mixed solution, which is chemically precipitated to form NH 4 CoPO 4 ·H 2 O purplish red precipitate. The NH is 4 Cl as NH 4 + A source; the CoCl 2 ·6H 2 O is used as a Co source; the NH is 4 H 2 PO 4 As PO 4 3+ A source; the NH is 3 ·H 2 O as NH 4 + Source and raise the pH of the mixed solution.
Step two: and pyrolyzing the mauve precipitate to obtain a blue precursor. The pyrolysis temperature is 250-550 ℃, and the reason for adopting the pyrolysis temperature is NH 4 CoPO 4 ·H 2 O will pass through the dehydrogenation in this temperature range 2 O, NH removal 3 Forming an amorphous cobalt phosphorus compound; the blue precursor is an amorphous cobalt phosphorus compound and has rich defects, so that in the subsequent electrochemical reduction processThe appearance of the ultrathin nano sheet is easier to generate.
Step three: mixing a blue precursor with nano carbon particles, adding the mixture into an alcohol solution containing a binder, and coating the mixture on an electrode substrate after ultrasonic homogenization to prepare a precursor electrode. The nano carbon particles can stably disperse cobalt-based ultrathin nano sheets, prevent agglomeration and increase the number of exposed active sites.
Step four: and (3) treating the precursor electrode under a reduction potential to obtain the catalytic electrode. Due to Co 2+ The cobalt-phosphorus compound can be reduced to zero-valent Co at-0.5V (relative to a saturated Ag/AgCl reference electrode of potassium chloride) and more negative potential, and in order to ensure that the amorphous cobalt-phosphorus compound is subjected to reduction reaction and take the problem of energy consumption into consideration, the reduction potential is-1 to-2V (relative to a saturated Ag/AgCl reference electrode of potassium chloride), so that the cobalt-phosphorus compound can form ultrathin cobalt-based nanosheets under the stable dispersion action of nano carbon particles. The catalytic electrode exposes a large number of high-activity sites, so that the catalytic electrode has excellent electrochemical reduction performance of nitrate; in addition, the addition of the nano carbon particles can stabilize the dispersed ultrathin cobalt-based nano sheets, so that the catalytic electrode has excellent cycle stability.
Example 1
The cobalt-based catalytic electrode for electrocatalytically reducing nitrate to ammonia was prepared by the following steps:
step one: 1.0 g NH 4 Cl、100 mg CoCl 2 ·6H 2 O、50 mg NH 4 H 2 PO 4 、400 μL NH 3 ·H 2 Adding O into 20 mL water, stirring for 5 h, filtering, cleaning with deionized water, and oven drying under vacuum to obtain mauve precipitate;
step two: pyrolyzing the mauve precipitate under the conditions of air atmosphere and 250 ℃ for 5 h to obtain a blue precursor;
step three: adding the precursor into an ethanol solution containing 5% of polytetrafluoroethylene, performing ultrasonic treatment to form a uniform suspension, and spraying the uniform suspension onto a carbon paper substrate to enable the precursor loading capacity to reach 5mg/cm 2 Fully drying to obtain a precursor electrode;
step four: the precursor electrode is used as a working electrode, a graphite carbon rod is used as a counter electrode, and Ag/AgCl saturated by potassium chloride is used as a reference electrode, and a voltage of-1.2V is applied and reduced for 60 min to obtain the catalytic electrode.
Example 2
A method of preparing a cobalt-based catalytic electrode for electrocatalytic reduction of nitrate to ammonia comprising the steps of:
step one: 10 mL deionized water and 10 mL glycerin are mixed and stirred uniformly, 3.0 g NH is added 4 Cl,、350 mg CoCl 2 ·6H 2 O、150 mg NH 4 H 2 PO 4 、360 μL NH 3 ·H 2 O, stirring 12 and h, filtering, cleaning with deionized water, and drying under vacuum to obtain mauve precipitate;
step two: pyrolyzing the mauve precipitate at 350 ℃ under nitrogen atmosphere for 3 h to obtain a blue precursor;
step three: adding a precursor and nano carbon particles into isopropanol solution containing 0.5% of perfluorosulfonic acid resin according to the mass ratio of 1:1, ultrasonically forming uniform suspension, and dripping the uniform suspension onto a foam nickel substrate to ensure that the precursor loading capacity reaches 1 mg/cm 2 Sufficiently drying to obtain the precursor electrode shown in figure 2;
step four: in a three-electrode system, a precursor electrode is used as a working electrode, ruthenium iridium titanium is used as a counter electrode, silver/silver chloride saturated with potassium chloride is used as a reference electrode, a voltage of-1.4V is applied, and the electrode is treated for 120min to obtain the catalytic electrode shown in figure 3, wherein the mapping diagrams of HAADF, co and C are shown in figure 4.
Example 3
A method of preparing a cobalt-based catalytic electrode for electrocatalytic reduction of nitrate to ammonia comprising the steps of:
step one: 5.0 g NH 4 Cl、500 mg CoCl 2 ·6H 2 O、300 mg NH 4 H 2 PO 4 、400 μL NH 3 ·H 2 Adding O into 50 mL glycerol, stirring for 24-h, filtering, cleaning with deionized water, and oven drying under vacuum to obtain mauve precipitate;
step two: pyrolyzing the mauve precipitate at 400 ℃ under helium atmosphere for 1 h to obtain a blue precursor;
step three: adding the precursor and the nano carbon particles into isopropanol solution containing 0.5% of polyvinylidene fluoride according to the mass ratio of 1:10, forming uniform suspension by ultrasonic, and brushing the uniform suspension on a cobalt mesh substrate to ensure that the catalyst loading capacity reaches 3 mg/cm 2 Fully drying to obtain a precursor electrode;
step four: in a three-electrode system, a precursor electrode is used as a working electrode, a graphite carbon rod is used as a counter electrode, ag/AgCl saturated by potassium chloride is used as a reference electrode, and a voltage of-2V is applied for 10 min to obtain a catalytic electrode.
Example 4
The catalytic electrode prepared in example 2 was cut to a size of 4 cm long and 2.25 wide and cm wide, and treated for 120min at normal temperature and pressure at-1.4V voltage in a standard dual-chamber electrolytic cell of a three-electrode system with ruthenium iridium titanium as a counter electrode, silver/AgCl saturated with potassium chloride as a reference electrode, and a mixed solution of 0.1M sodium sulfate and 200 mg N/L sodium nitrate as an electrolyte. The concentrations of nitrate, nitrite and ammonia in the electrolyte are measured by a spectrophotometry, and the conversion rate of the nitrate is 99.99%, the yield of the nitrite is 0% and the yield of the ammonia is 98.78% after analysis.
Example 5
The catalytic electrode prepared in example 2 was cut to a size of 4 cm long and 2.25 wide and cm wide, and treated for 120min at normal temperature and pressure under-1.4V voltage in a two-compartment electrolytic cell of a three-electrode system with ruthenium iridium titanium as a counter electrode, silver/AgCl saturated with potassium chloride as a reference electrode, and a mixed solution of 0.1M sodium sulfate and 200 mg N/L sodium nitrate as an electrolyte. Then the electrolyte was replaced and the test was continuously repeated 7 times under the same conditions. The concentration of nitrate, nitrite and ammonia in the electrolyte is determined by spectrophotometry, and the dissolution concentration of cobalt is determined by ICP-MS. The conversion rate of nitrate radical obtained by analysis is maintained above 99.9%, the production rate of nitrite radical is 0%, and the production rate of ammonia is greater than 96.78% (shown in figure 5); the cobalt elution amounts were less than 30. Mu.g/L (as shown in FIG. 6).
The foregoing is illustrative of the present invention and is not to be construed as limiting thereof, and any modification, equivalent replacement, improvement or the like which comes within the spirit and principles of the present invention are intended to be included within the scope of the present invention.
Claims (6)
1. A method for preparing a cobalt-based catalytic electrode for electrocatalytic reduction of nitrate to ammonia, comprising the steps of:
step one: NH is added to 4 Cl、CoCl 2 ·6H 2 O、NH 4 H 2 PO 4 And NH 3 ·H 2 Mixing the four solutions, fully stirring, filtering, and drying to obtain a mauve precipitate;
step two: pyrolyzing the mauve precipitate obtained in the first step in one or more mixed atmospheres of air, argon, helium or nitrogen at the temperature of 250-550 ℃ for 0.5-5 hours to obtain a blue precursor;
step three: mixing the precursor obtained in the second step with nano carbon particles, adding the mixture into an alcohol solution containing a binder, and coating the mixture on an electrode substrate to prepare a precursor electrode after ultrasonic homogenization;
step four: and (3) treating the precursor electrode prepared in the step (III) for 10-120 min under the condition that the reduction potential is minus 1 to minus 2V relative to the Ag/AgCl reference electrode saturated by potassium chloride, so as to obtain the cobalt-based catalytic electrode.
2. The method for preparing the cobalt-based catalytic electrode by electrocatalytic reduction of nitrate to ammonia according to claim 1, wherein in the third step, the mass ratio of the precursor to the nano carbon particles is 1:10-1:0, the binder is one or a combination of more of perfluorosulfonic acid resin, polytetrafluoroethylene and polyvinylidene fluoride, and the loading amount of the precursor is 0.1-5 mg/cm 2 。
3. The method for preparing a cobalt-based catalytic electrode for electrocatalytic reduction of nitrate to ammonia according to claim 1, wherein in the third step, the electrode substrate is one of nickel foam, titanium foam, copper foam, cobalt foam, nickel mesh, titanium mesh, copper mesh, cobalt mesh, carbon paper, carbon felt and glass carbon; the coating technology is one or a combination of a plurality of dripping, spraying, sputtering and brushing.
4. The method for preparing the cobalt-based catalytic electrode for electrocatalytic reduction of nitrate to ammonia according to claim 1, wherein in the fourth step, a three-electrode system is used, the counter electrode is one or a combination electrode of several metals of graphite carbon rod electrode, platinum electrode, gold electrode, ruthenium electrode and titanium electrode, and the distance between the counter electrode and the working electrode is 0.5-10 cm.
5. The cobalt-based catalytic electrode for electrocatalytic reduction of nitrate to ammonia prepared by the preparation method according to any one of claims 1-4, wherein the cobalt-based material on the electrode is in ultra-thin nano-sheet shape with average thickness of 2-15 nm.
6. The cobalt-based catalytic electrode for electrocatalytic reduction of nitrate to ammonia according to claim 5, wherein the electrode has a nitrate conversion rate of 99% or more and an ammonia generation rate of 98% or more, and the number of times of recycling is 8 or more.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202210702566.3A CN114836770B (en) | 2022-06-21 | 2022-06-21 | Cobalt-based catalytic electrode for electrocatalytic reduction of nitrate radical into ammonia and preparation method thereof |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202210702566.3A CN114836770B (en) | 2022-06-21 | 2022-06-21 | Cobalt-based catalytic electrode for electrocatalytic reduction of nitrate radical into ammonia and preparation method thereof |
Publications (2)
Publication Number | Publication Date |
---|---|
CN114836770A CN114836770A (en) | 2022-08-02 |
CN114836770B true CN114836770B (en) | 2024-01-16 |
Family
ID=82574125
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN202210702566.3A Active CN114836770B (en) | 2022-06-21 | 2022-06-21 | Cobalt-based catalytic electrode for electrocatalytic reduction of nitrate radical into ammonia and preparation method thereof |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN114836770B (en) |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN114497590A (en) * | 2022-02-10 | 2022-05-13 | 易航时代(北京)科技有限公司 | Nitrogen-phosphorus co-doped carbon fiber loaded CoP composite material, preparation method and application thereof, and aluminum-air battery |
-
2022
- 2022-06-21 CN CN202210702566.3A patent/CN114836770B/en active Active
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN114497590A (en) * | 2022-02-10 | 2022-05-13 | 易航时代(北京)科技有限公司 | Nitrogen-phosphorus co-doped carbon fiber loaded CoP composite material, preparation method and application thereof, and aluminum-air battery |
Also Published As
Publication number | Publication date |
---|---|
CN114836770A (en) | 2022-08-02 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN110970630B (en) | CuO nanosheet and top-down preparation method and application thereof | |
CN113005469B (en) | Ruthenium-loaded amorphous nickel hydroxide/nickel phosphide composite electrode and preparation method and application thereof | |
CN113718281B (en) | Graphene quantum dot/MXene nanosheet two-dimensional composite material and preparation method and application thereof | |
CN109852992B (en) | Efficient electrocatalytic full-decomposition water nanosheet array electrode and preparation method and application thereof | |
CN106784881B (en) | A kind of noble metal/vertical growth hydrotalcite nano piece methanol fuel cell catalyst and preparation method thereof | |
CN111036247B (en) | Cobalt-iron oxide-cobalt phosphate electrocatalytic oxygen evolution composite material and preparation method and application thereof | |
CN108232213A (en) | A kind of nitrogen-doped graphene-carbon nanotube-cobaltosic oxide hybrid material and preparation method thereof | |
CN112090436B (en) | Nickel-based catalyst, preparation method and application | |
CN110965076A (en) | Preparation method of electrolytic water electrode with double-function three-dimensional layered core-shell structure | |
CN113279005A (en) | Cobalt doped MoS2/NiS2Preparation method of porous heterostructure material and application of material in electrocatalytic hydrogen evolution | |
CN114657592B (en) | Nickel-based catalyst for electrocatalytic carbon dioxide reduction and preparation method thereof | |
CN110699701B (en) | Foam nickel loaded with metal nickel and vanadium trioxide compound and preparation method and application thereof | |
CN112007677A (en) | Nitrogen-doped iron nanotube, and preparation method and application thereof | |
CN113737218A (en) | Copper-based graphene aerogel composite catalyst, gas diffusion electrode and application | |
CN116145193B (en) | Copper-based catalyst for electrocatalytic reduction of nitrate radical into ammonia and preparation method thereof | |
CN114836770B (en) | Cobalt-based catalytic electrode for electrocatalytic reduction of nitrate radical into ammonia and preparation method thereof | |
CN113463131B (en) | Copper monatomic catalyst and preparation method and application thereof | |
CN113529133B (en) | Preparation method of self-supporting type bifunctional catalytic electrode | |
CN113502497B (en) | Electrocatalyst for regulating and controlling performance of low-temperature plasma and preparation method and application thereof | |
CN114774983A (en) | Ultra-small Ru nanocluster loaded on MoO3-xDouble-function composite material of nanobelt and preparation method and application thereof | |
CN112624176A (en) | Oxygen vacancy-rich CuO nanosheet and preparation method and application thereof | |
CN108911048B (en) | Preparation method of multi-scale salient point electrode | |
CN115125576B (en) | Composite selenide electrocatalyst and preparation method and application thereof | |
CN115011997B (en) | Self-supporting hollow sugarcoated haws-end electrocatalyst and preparation method and application thereof | |
CN113403641B (en) | Electrocatalytic material and preparation method and application thereof |
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 | ||
GR01 | Patent grant | ||
GR01 | Patent grant |