CN115786959A - Electrochemical preparation method of carbon-supported nickel-iron double-metal hydroxide catalyst for synthesizing ammonia by electro-reduction of nitrate - Google Patents
Electrochemical preparation method of carbon-supported nickel-iron double-metal hydroxide catalyst for synthesizing ammonia by electro-reduction of nitrate Download PDFInfo
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- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 title claims abstract description 185
- 229910021529 ammonia Inorganic materials 0.000 title claims abstract description 87
- 239000003054 catalyst Substances 0.000 title claims abstract description 65
- UGKDIUIOSMUOAW-UHFFFAOYSA-N iron nickel Chemical compound [Fe].[Ni] UGKDIUIOSMUOAW-UHFFFAOYSA-N 0.000 title claims abstract description 58
- 229910002651 NO3 Inorganic materials 0.000 title claims abstract description 22
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 title claims abstract description 22
- 230000002194 synthesizing effect Effects 0.000 title claims abstract description 16
- 238000002360 preparation method Methods 0.000 title claims abstract description 11
- 229910000000 metal hydroxide Inorganic materials 0.000 title claims description 41
- 238000006243 chemical reaction Methods 0.000 claims abstract description 81
- 239000000243 solution Substances 0.000 claims abstract description 57
- 238000004070 electrodeposition Methods 0.000 claims abstract description 44
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims abstract description 36
- 239000011259 mixed solution Substances 0.000 claims abstract description 36
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 33
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 33
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims abstract description 27
- 229910021607 Silver chloride Inorganic materials 0.000 claims abstract description 20
- 229910052786 argon Inorganic materials 0.000 claims abstract description 18
- 239000007789 gas Substances 0.000 claims abstract description 18
- 238000000034 method Methods 0.000 claims abstract description 13
- 239000010411 electrocatalyst Substances 0.000 claims abstract description 9
- 229910052697 platinum Inorganic materials 0.000 claims abstract description 6
- HKZLPVFGJNLROG-UHFFFAOYSA-M silver monochloride Chemical compound [Cl-].[Ag+] HKZLPVFGJNLROG-UHFFFAOYSA-M 0.000 claims abstract description 4
- 238000001035 drying Methods 0.000 claims description 25
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims description 21
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 21
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 claims description 18
- 239000004202 carbamide Substances 0.000 claims description 18
- 239000008367 deionised water Substances 0.000 claims description 18
- 229910021641 deionized water Inorganic materials 0.000 claims description 18
- DDFHBQSCUXNBSA-UHFFFAOYSA-N 5-(5-carboxythiophen-2-yl)thiophene-2-carboxylic acid Chemical compound S1C(C(=O)O)=CC=C1C1=CC=C(C(O)=O)S1 DDFHBQSCUXNBSA-UHFFFAOYSA-N 0.000 claims description 17
- SZQUEWJRBJDHSM-UHFFFAOYSA-N iron(3+);trinitrate;nonahydrate Chemical compound O.O.O.O.O.O.O.O.O.[Fe+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O SZQUEWJRBJDHSM-UHFFFAOYSA-N 0.000 claims description 16
- 238000005406 washing Methods 0.000 claims description 16
- AOPCKOPZYFFEDA-UHFFFAOYSA-N nickel(2+);dinitrate;hexahydrate Chemical compound O.O.O.O.O.O.[Ni+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O AOPCKOPZYFFEDA-UHFFFAOYSA-N 0.000 claims description 15
- 230000009467 reduction Effects 0.000 claims description 9
- NLXLAEXVIDQMFP-UHFFFAOYSA-N Ammonia chloride Chemical compound [NH4+].[Cl-] NLXLAEXVIDQMFP-UHFFFAOYSA-N 0.000 claims description 8
- PUZPDOWCWNUUKD-UHFFFAOYSA-M sodium fluoride Chemical compound [F-].[Na+] PUZPDOWCWNUUKD-UHFFFAOYSA-M 0.000 claims description 8
- 238000005868 electrolysis reaction Methods 0.000 claims description 7
- 238000003756 stirring Methods 0.000 claims description 7
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 claims description 6
- MIMUSZHMZBJBPO-UHFFFAOYSA-N 6-methoxy-8-nitroquinoline Chemical compound N1=CC=CC2=CC(OC)=CC([N+]([O-])=O)=C21 MIMUSZHMZBJBPO-UHFFFAOYSA-N 0.000 claims description 5
- MQRWBMAEBQOWAF-UHFFFAOYSA-N acetic acid;nickel Chemical compound [Ni].CC(O)=O.CC(O)=O MQRWBMAEBQOWAF-UHFFFAOYSA-N 0.000 claims description 4
- 235000019270 ammonium chloride Nutrition 0.000 claims description 4
- 229940078494 nickel acetate Drugs 0.000 claims description 4
- 239000011775 sodium fluoride Substances 0.000 claims description 4
- 235000013024 sodium fluoride Nutrition 0.000 claims description 4
- 229910021578 Iron(III) chloride Inorganic materials 0.000 claims description 3
- RBTARNINKXHZNM-UHFFFAOYSA-K iron trichloride Chemical compound Cl[Fe](Cl)Cl RBTARNINKXHZNM-UHFFFAOYSA-K 0.000 claims description 3
- RUTXIHLAWFEWGM-UHFFFAOYSA-H iron(3+) sulfate Chemical compound [Fe+3].[Fe+3].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O RUTXIHLAWFEWGM-UHFFFAOYSA-H 0.000 claims description 3
- PVFSDGKDKFSOTB-UHFFFAOYSA-K iron(3+);triacetate Chemical compound [Fe+3].CC([O-])=O.CC([O-])=O.CC([O-])=O PVFSDGKDKFSOTB-UHFFFAOYSA-K 0.000 claims description 3
- 229910000360 iron(III) sulfate Inorganic materials 0.000 claims description 3
- LGQLOGILCSXPEA-UHFFFAOYSA-L nickel sulfate Chemical compound [Ni+2].[O-]S([O-])(=O)=O LGQLOGILCSXPEA-UHFFFAOYSA-L 0.000 claims description 3
- 229910000363 nickel(II) sulfate Inorganic materials 0.000 claims description 3
- 239000011780 sodium chloride Substances 0.000 claims description 3
- 235000002639 sodium chloride Nutrition 0.000 claims description 2
- 230000035484 reaction time Effects 0.000 claims 1
- 229910052751 metal Inorganic materials 0.000 abstract description 9
- 239000002184 metal Substances 0.000 abstract description 9
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 abstract description 8
- 239000001257 hydrogen Substances 0.000 abstract description 8
- 229910052739 hydrogen Inorganic materials 0.000 abstract description 8
- FGIUAXJPYTZDNR-UHFFFAOYSA-N potassium nitrate Chemical compound [K+].[O-][N+]([O-])=O FGIUAXJPYTZDNR-UHFFFAOYSA-N 0.000 abstract description 4
- 238000007086 side reaction Methods 0.000 abstract description 4
- 229920000049 Carbon (fiber) Polymers 0.000 abstract description 3
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 abstract description 3
- 239000004917 carbon fiber Substances 0.000 abstract description 3
- 239000001301 oxygen Substances 0.000 abstract description 3
- 229910052760 oxygen Inorganic materials 0.000 abstract description 3
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 abstract description 2
- 230000008878 coupling Effects 0.000 abstract 1
- 238000010168 coupling process Methods 0.000 abstract 1
- 238000005859 coupling reaction Methods 0.000 abstract 1
- 235000010333 potassium nitrate Nutrition 0.000 abstract 1
- 239000003792 electrolyte Substances 0.000 description 42
- 238000011049 filling Methods 0.000 description 18
- 238000002798 spectrophotometry method Methods 0.000 description 16
- VRZJGENLTNRAIG-UHFFFAOYSA-N 4-[4-(dimethylamino)phenyl]iminonaphthalen-1-one Chemical compound C1=CC(N(C)C)=CC=C1N=C1C2=CC=CC=C2C(=O)C=C1 VRZJGENLTNRAIG-UHFFFAOYSA-N 0.000 description 15
- 239000007788 liquid Substances 0.000 description 13
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 12
- 238000011068 loading method Methods 0.000 description 10
- 150000004692 metal hydroxides Chemical class 0.000 description 10
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 8
- 230000015572 biosynthetic process Effects 0.000 description 7
- 230000000694 effects Effects 0.000 description 7
- 238000011160 research Methods 0.000 description 7
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 6
- 238000000151 deposition Methods 0.000 description 6
- 230000008021 deposition Effects 0.000 description 6
- 239000000203 mixture Substances 0.000 description 6
- 238000003786 synthesis reaction Methods 0.000 description 6
- IOVCWXUNBOPUCH-UHFFFAOYSA-M Nitrite anion Chemical compound [O-]N=O IOVCWXUNBOPUCH-UHFFFAOYSA-M 0.000 description 4
- 229910052742 iron Inorganic materials 0.000 description 4
- 229910052757 nitrogen Inorganic materials 0.000 description 4
- 230000008569 process Effects 0.000 description 4
- 230000004913 activation Effects 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 3
- 230000003197 catalytic effect Effects 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 230000007547 defect Effects 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- 229910052759 nickel Inorganic materials 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 2
- 230000002860 competitive effect Effects 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 2
- 238000002848 electrochemical method Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 229910044991 metal oxide Inorganic materials 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000027756 respiratory electron transport chain Effects 0.000 description 2
- LHGMHYDJNXEEFG-UHFFFAOYSA-N 4-[4-(dimethylamino)phenyl]iminocyclohexa-2,5-dien-1-one Chemical compound C1=CC(N(C)C)=CC=C1N=C1C=CC(=O)C=C1 LHGMHYDJNXEEFG-UHFFFAOYSA-N 0.000 description 1
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 description 1
- 241000282326 Felis catus Species 0.000 description 1
- 229910001030 Iron–nickel alloy Inorganic materials 0.000 description 1
- 229910003271 Ni-Fe Inorganic materials 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 150000001450 anions Chemical class 0.000 description 1
- 239000012752 auxiliary agent Substances 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 238000006555 catalytic reaction Methods 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000013064 chemical raw material Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 230000005518 electrochemistry Effects 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 239000003344 environmental pollutant Substances 0.000 description 1
- 239000004744 fabric Substances 0.000 description 1
- 239000003337 fertilizer Substances 0.000 description 1
- 239000005431 greenhouse gas Substances 0.000 description 1
- 238000009830 intercalation Methods 0.000 description 1
- 230000002687 intercalation Effects 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- -1 nickel iron metal oxide Chemical class 0.000 description 1
- DWAHIRJDCNGEDV-UHFFFAOYSA-N nickel(2+);dinitrate;hydrate Chemical compound O.[Ni+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O DWAHIRJDCNGEDV-UHFFFAOYSA-N 0.000 description 1
- 150000002823 nitrates Chemical class 0.000 description 1
- 229910000510 noble metal Inorganic materials 0.000 description 1
- 231100000719 pollutant Toxicity 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 238000001308 synthesis method Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 238000010792 warming Methods 0.000 description 1
- 238000005303 weighing Methods 0.000 description 1
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- 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
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/10—Process efficiency
- Y02P20/133—Renewable energy sources, e.g. sunlight
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- Electrolytic Production Of Non-Metals, Compounds, Apparatuses Therefor (AREA)
- Catalysts (AREA)
Abstract
An electrochemical preparation method of a carbon-coupled nickel-iron-based catalyst for synthesizing ammonia by electro-reduction of nitrate and an application thereof are disclosed. Adding the mixed solution into a pre-assembled electrodeposition tank, performing electrodeposition in a constant-pressure mode, and coupling the cathode plate with carbon to the nickel-iron-based electrocatalyst after the reaction is finished. When the carbon-coupled nickel-iron-based electrocatalyst is applied, the carbon-coupled nickel-iron-based electrocatalyst is used as a cathode plate, a commercial platinum sheet electrode is used as an anode plate, a commercial platinum sheet electrode is used as Ag/AgCl, a three-electrode system H-shaped electrolytic cell is assembled, a mixed solution of KNO3 and KOH is filled into a cathode, and an equivalent KOH solution is filled into an anode to form a reaction cell. And opening a gas switch, introducing high-purity argon, and continuously electrolyzing. The invention can effectively inhibit the generation of hydrogen evolution side reaction, meanwhile, the combination of abundant oxygen vacancies on the surface of the carbon fiber paper and metal active sites obtains extremely high Faraday efficiency, and the metal loaded by the electrodeposition method has excellent circulating stability and can be reacted for a long time.
Description
Technical Field
The invention relates to an electrochemical preparation method of a carbon-supported nickel-iron double-metal hydroxide catalyst for synthesizing ammonia by electro-reduction of nitrate, belonging to the fields of chemical industry and electro-catalysis.
Background
Ammonia is an important chemical raw material and has important application in the fields of fertilizers, hydrogen storage, coatings and the like. At present, the industrial synthesis method of ammonia is mainly a Haber-Bosch method, which reacts under high temperature and high pressure (400-600 ℃,150-300 atm), consumes a large amount of fossil energy (about 2% of the annual global energy consumption), and the combustion of the fossil energy causes the reaction to emit a large amount of greenhouse gases, thereby causing negative effects such as global warming. In recent years, NH has been artificially synthesized by an electrochemical method 3 The electrochemical synthesis ammonia technology adopts wind power and photovoltaic energy supply, takes water as a hydrogen source, obviously reduces the emission of carbon dioxide, reacts at normal temperature and normal pressure, and has no by-products which are difficult to treat. However, since nitrogen is used as the nitrogen source, N 2 Poor solubility in water, strong N ≡ N bond energy, difficult activation and competitive Hydrogen Evolution Reaction (HER) limitations of NH 3 Very low yields (about 0.1-100. Mu.g h) -1 mg cat -1 ) Therefore, the new technology cannot be applied to mass production of NH 3 . Although researchers have proposed various methods of surface vacancy engineering, surface molecular grafting, internal electric field regulation, novel three-phase systems, etc. to improve the efficiency of ammonia synthesis throughout the system, the distance is not so greatThere is still a great gap in achieving large-scale applications.
As mentioned above, the nitrogen-nitrogen triple bond (942 kJ/mol) in nitrogen is strong, strong in binding, and difficult to activate. If abundant nitrate and nitrite are used as nitrogen source, the nitrogen-oxygen double bond (607 kJ/mol) bond energy is thermodynamically lower, and the activation energy is easier to activate and dissociate, so the reaction activation energy is lower. In terms of kinetics, the solubility of nitrate and nitrite is higher, and the mass transfer rate is faster, so that the ammonia production efficiency can be obviously improved. In addition, nitrate and nitrite exist widely in polluted water systems, and if the nitrate and nitrite are reduced by an electrochemical method, pollutants can be removed, and product ammonia with high added value can be obtained. Currently, the synthesis of ammonia (NO) by electroreduction of nitrates 3 RR) system most of the catalyst research has focused on metal-based catalysts (noble metals, alloys, metal oxides, etc.). For this type of catalyst, there are two problems that seriously affect the reaction efficiency: firstly, various metals are easy to corrode, and particularly, the stability is poor under an acidic or alkaline electrolytic system, so that the large-scale application of the metals is hindered; secondly, the hydrogen evolution reaction (HER, 2H) of two electron transfer in the electrolyte occurs in the reaction process of the metal-based catalyst + +2e - →H 2 ) Is NO with 8 electron transfer 3 RR reaction (NO) 3 RR，NO 3 - +9H + +8e - →NH 3 +3H 2 O) due to the faster kinetic reaction rate of the hydrogen evolution reaction, resulting in NO 3 RR has low Faraday efficiency and poor stability, and finally, further development of nitrate synthetic ammonia is hindered.
In summary, most of the catalysts used for electrocatalysis of nitrate to synthesize ammonia are metal catalysts, which have low reaction selectivity, poor corrosion resistance, poor cycle stability and the like, and finally result in NO 3 RR poor selectivity and stability, block NO 3 The RR process is further developed. In order to overcome the defects of the prior art, the carbon paper is adopted as a conductive substrate, the high-selectivity nickel-iron bimetal hydroxide is loaded on the surface of the carbon paper and is used as an integral catalyst to drive NO 3 RR synthetic ammonia; providing an electrocatalytic nitrate complexThe electrochemical preparation method of the carbon-supported nickel-iron double-metal hydroxide catalyst for ammonia formation avoids the problems of strong competition of side reaction HER and the like, and improves NO 3 RR selectivity.
Disclosure of Invention
In order to overcome the defects in the prior art, the invention aims to provide an electrochemical preparation method of a carbon-supported nickel-iron double-metal hydroxide catalyst for synthesizing ammonia by electrocatalytic nitrate reduction, which is used for relieving NO 3 The problems of competitive interference of side reaction HER and the like in the RR process, and finally NO is improved 3 RR selectivity.
In order to achieve the purpose of the invention and solve the problems in the prior art, the invention adopts the technical scheme that:
an electrochemical preparation method of a carbon-supported nickel-iron double hydroxide catalyst for synthesizing ammonia by electrocatalysis of nitrate reduction comprises the following steps:
And 2, taking an electrode clamped with 2cm × 3cm of hydrophilic carbon paper as a cathode plate, taking a 2cm × 2cm commercial platinum sheet electrode as an anode plate, and assembling an electrodeposition cell by taking Ag/AgCl (saturated KCl solution as a filling liquid) as a reference electrode and an electrochemical workstation (CHI 660E). The hydrophilic carbon paper comprises carbon cloth and carbon fibers.
And 3, adding the mixed solution into a pre-assembled electrodeposition pool, setting the voltage to be-1V to-2V, keeping the temperature at 25 ℃, and performing electrodeposition reaction in a constant-voltage mode for 5-60min. And after the reaction is finished, taking out the cathode plate, washing the cathode plate by using deionized water, drying the cathode plate in a 60-degree oven for 6 hours, taking out the cathode plate, weighing the cathode plate, and calculating the deposition load to obtain the carbon-supported nickel-iron double metal hydroxide electrocatalyst.
An electrochemical preparation method of a carbon-supported nickel-iron double-metal hydroxide catalyst for synthesizing ammonia by electrocatalysis of nitrate reduction comprises the following specific steps: cutting the carbon-supported nickel-iron bimetallic hydroxide electrocatalyst into 1cm multiplied by 1cm thin sheets serving as cathode plates, 1cm multiplied by 1cm commercial platinum sheet electrodes serving as anode plates, taking Ag/AgCl (filling solution is saturated KCl solution) as reference electrodes, assembling into an H-shaped electrolytic cell of a three-electrode system, and filling 1-3009mM/L KNO into the cathode 3 Mixing with 0.1M/L KOH, wherein the concentration of KOH in the mixed solution is 0.1M/L, KNO 3 The concentration of (b) is not more than its saturation concentration (< 3009 mM/L). The anode was filled with an equivalent amount of 0.1M/L KOH solution and assembled into a reaction cell. Opening the gas switch for 10-50mL min -1 Continuously introducing high-purity argon at the flow rate, opening a power switch of the electrochemical workstation after 30min, and setting the voltage to be-0.6V to-2.3V for continuous electrolysis for 1-4 h. After the reaction is finished, detecting the ammonia concentration of the electrolyte after the reaction by using an indophenol blue spectrophotometry and an ammonia sensitive electrode in the cathode pool solution, and calculating the Faraday efficiency and the ammonia yield.
The invention has the beneficial effects that:
the carbon paper adopted by the invention has abundant oxygen vacancies and defect sites, and is beneficial to NO 3 - To NO 2 - And this step is also NO 3 And (3) determining the rate of RR. The addition of auxiliary agents such as sodium fluoride, ammonium chloride and ammonium fluoride (ammonium bifluoride) in the electrodeposition liquid plays a role in surface modification, ions play a role in the synthesis of the double-metal hydroxide, so that the synthesized Ni-Fe LDH forms a sheet corolla-shaped structure on the surface of the carbon paper, urea (sodium hydroxide) is decomposed into ammonium and carbonate in the electrodeposition process, an alkaline environment is provided for the synthesis of the double-metal hydroxide, and the carbonate exists in the catalyst as intercalation anions. The synthesized double metal hydroxide catalyst has NO reaction 3 In the case of RR reaction, the occurrence of hydrogen evolution side reaction can be effectively inhibited, and meanwhile, the combination of abundant oxygen vacancies on the surface of the carbon fiber paper and the active sites of the double metal hydroxide is synergistically improvedFaraday efficiency, and in addition, the supported double metal hydroxide prepared by the electrodeposition method has excellent cycle stability and can be used for long-term NO 3 And (3) RR process.
Drawings
FIG. 1 is a graph comparing the yield of synthetic ammonia and the Faraday efficiency for materials synthesized in different ratios for examples 1, 2, 3, and comparative examples 1, 2;
FIG. 2 is a graph of the effect of different catalyst loadings on synthetic ammonia concentration and Faraday efficiency for examples 4, 5, and 6;
FIG. 3 is a graph showing the effect of different applied voltages on the concentration of synthetic ammonia and the Faraday efficiency in examples 7, 8 and 9;
FIG. 4 is a graph comparing the yield of synthetic ammonia and the Faraday efficiency for different concentrations of nitrate electrolyte for examples 10, 11, 12;
figure 5 is a comparison of the performance of the catalyst formed by the electrodeposition operation performed on example 13 with a blank hydrophilic carbon paper catalyst.
Detailed Description
The invention is further illustrated by the following examples in conjunction with the drawings.
COMPARATIVE EXAMPLE 1 (iron only)
Rapidly and uniformly stirring ferric nitrate nonahydrate, ammonium fluoride and urea (the concentrations are 0.1M, 1.6mM and 4mM respectively) by using a magnetic stirrer to obtain a mixed solution, adding the mixed solution into the pre-assembled electrodeposition tank, and carrying out electrodeposition for 5min by adopting a constant temperature and constant pressure (the voltage is set to be-1V, and the temperature is set to be 25 ℃ and constant temperature). And after the reaction is finished, taking out the cathode plate, washing the cathode plate by using deionized water, and drying the cathode plate in a 60-degree oven for 6 hours. The obtained carbon-supported nickel-iron double-metal hydroxide catalyst is used as a cathode plate, a commercial Pt sheet electrode is adopted as an anode plate, ag/AgCl (saturated KCl solution as filling liquid) is adopted as a reference electrode, 30mL of 0.1M KNO is filled in a cathode pool 3 The solution was mixed with 0.1M KOH and the anode was charged with 30mL of 0.1M KOH solution. Turn on the gas switch for 10mL min -1 Continuously introducing high-purity argon at the flow rate, opening a power switch of the electrochemical workstation after 30min, and setting the electrolysis voltage to-1.3V for continuous reaction. After the reaction is finished, collecting the electrolyte of the cathode pool, and using indigoThe ammonia concentration of the electrolyte after the reaction was detected by phenol blue spectrophotometry and an ammonia gas sensitive electrode, and the faradaic efficiency and ammonia yield were calculated, and the results are shown in fig. 3. As can be seen, when the bath is a pure iron solution, fe (OH) is produced 3 the/CC can reach faradaic efficiency of nearly 100 percent and 125nmol s -1 cm -2 Ammonia yield of (2), however, due to Fe (OH) 3 Fe of/CC 3+ Compared with NiFe LDH/CC, the catalyst has poorer cycle stability, and the performance of the catalyst is reduced to 60 percent of the initial performance after 10 times of cycle tests, so the catalyst is not an ideal slave catalyst.
COMPARATIVE EXAMPLE 2 (Nickel only)
Nickel nitrate hexahydrate, ammonium bifluoride and sodium hydroxide (the concentrations of which are 0.1M, 1.6mM and 4mM respectively) are rapidly and uniformly stirred by a magnetic stirrer to obtain a mixed solution, the mixed solution is added into the pre-assembled electrodeposition tank, and electrodeposition is carried out for 5min by adopting a constant temperature and constant pressure (voltage is set to be-1V, and temperature is set to be 25 ℃ and constant temperature). And after the reaction is finished, taking out the cathode plate, washing the cathode plate by using deionized water, and drying the cathode plate in a 60-degree drying oven for 6 hours. The carbon-supported nickel-iron double metal hydroxide catalyst obtained above was used as a cathode plate, a commercial Pt sheet electrode was used as an anode plate, ag/AgCl (saturated KCl solution as a filling solution) was used as a reference electrode, and 30mL of 0.1M KNO was charged in a cathode cell 3 The anode was charged with 30mL of 0.1M KOH solution mixed with 0.1M KOH. Turn on the gas switch for 10mL min -1 Continuously introducing high-purity argon at the flow rate, opening a power switch of the electrochemical workstation after 30min, and setting the electrolysis voltage to-1.3V for continuous reaction. After the reaction, the cathode pool electrolyte was collected, the ammonia concentration of the reacted electrolyte was detected by indophenol blue spectrophotometry and an ammonia sensitive electrode, and the faradaic efficiency and ammonia yield were calculated, the results are shown in fig. 3. As can be seen, when the bath is a pure iron solution, ni (OH) is produced 2 the/CC can reach 51 percent of Faraday efficiency and 46nmol s -1 cm -2 The ammonia yield of (a).
Example 1 (3
The different ratios of the carbon-supported nickel-iron double-metal hydroxide catalyst shown in the invention to NO are explored 3 Impact of RR performance. The specific operation is as follows: will sixThe nickel nitrate hydrate, the ferric nitrate nonahydrate, the sodium fluoride and the urea (the concentrations are 0.6mM, 0.2mM, 1.6mM and 4mM respectively) are rapidly and uniformly stirred by a magnetic stirrer to obtain a mixed solution, the mixed solution is added into the pre-assembled electrodeposition tank, and the electrodeposition is carried out for 5min by adopting a constant temperature and constant pressure mode (the voltage is set to be-1V, and the temperature is set to be 25 ℃ and constant temperature). And after the reaction is finished, taking out the cathode plate, washing the cathode plate by using deionized water, and drying the cathode plate in a 60-degree drying oven for 6 hours. The obtained carbon-supported nickel-iron double-metal hydroxide catalyst is used as a cathode plate, a commercial Pt sheet electrode is adopted as an anode plate, ag/AgCl (saturated KCl solution as filling liquid) is adopted as a reference electrode, 30mL of 0.1M KNO is filled in a cathode pool 3 The mixture was mixed with 0.1M KOH and the anode was charged with 30mL of 0.1M KOH solution. Turn on the gas switch for 10mL min -1 Continuously introducing high-purity argon at the flow rate, opening a power switch of the electrochemical workstation after 30min, and setting the electrolytic voltage to-1.1V for continuous reaction. After the reaction, the cathode cell electrolyte was collected, and the ammonia concentration of the electrolyte after the reaction was detected by indophenol blue spectrophotometry and an ammonia gas sensitive electrode, and the faradaic efficiency and ammonia yield were calculated, the results of which are shown in fig. 1. As can be seen from the figure, the carbon-supported iron-based catalyst, the carbon-supported nickel-based catalyst and the carbon-supported nickel-based catalyst are prepared according to the proportion of 2: 1. 3: 1. 4:1, when the nickel-iron ratio is 3:1 hour, the catalytic performance is better, and the Faraday efficiency and the ammonia yield respectively reach 96 percent and 90nmol s -1 cm -2 . The above results indicate that the nickel-iron ratio of the catalyst is an important factor affecting the ammonia synthesis performance of the carbon-supported nickel-iron double metal hydroxide catalyst.
Example 2 (4
Nickel nitrate hexahydrate, ferric nitrate nonahydrate, sodium chloride and urea (the concentrations of which are 0.8mM,0.2mM, 1.6mM and 4mM respectively) are rapidly and uniformly stirred by a magnetic stirrer to obtain a mixed solution, the mixed solution is added into the pre-assembled electrodeposition tank, and the electrodeposition is carried out for 5min by adopting a constant temperature and constant pressure (the voltage is set to be-1V, and the temperature is set to be 25 ℃ and constant temperature). And after the reaction is finished, taking out the cathode plate, washing the cathode plate by using deionized water, and drying the cathode plate in a 60-degree oven for 6 hours. The obtained carbon-supported nickel-iron bimetal hydrogenThe oxide catalyst is used as a cathode plate, a commercial Pt sheet electrode is used as an anode plate, ag/AgCl (saturated KCl solution is used as a filling liquid) is used as a reference electrode, and 30mL of 0.1M KNO is filled in a cathode pool 3 The solution was mixed with 0.1M KOH and the anode was charged with 30mL of 0.1M KOH solution. Turn on the gas switch for 10mL min -1 Continuously introducing high-purity argon at the flow rate, opening a power switch of the electrochemical workstation after 30min, and setting the electrolytic voltage to be-1.3V for continuous reaction. After the reaction, the cathode cell electrolyte was collected, and the ammonia concentration of the electrolyte after the reaction was detected by indophenol blue spectrophotometry and an ammonia gas sensitive electrode, and the faradaic efficiency and ammonia yield were calculated, the results of which are shown in fig. 3. As can be seen, when the nickel-iron ratio of the electrodeposition liquid is 4:1 hour, ni prepared 4 Fe 1 LDH/CC can reach 83% of Faraday efficiency and 69nmol s -1 cm -2 The ammonia yield of (a).
Example 3 (2
Nickel nitrate hexahydrate, ferric nitrate nonahydrate, ammonium chloride and urea (the concentrations of which are 0.4mM, 0.2mM, 1.6mM and 4mM respectively) are rapidly and uniformly stirred by a magnetic stirrer to obtain a mixed solution, the mixed solution is added into the pre-assembled electrodeposition tank, and the electrodeposition is carried out for 5min by adopting a constant temperature and constant pressure (the voltage is set to be-1V, and the temperature is set to be 25 ℃ and constant temperature). And after the reaction is finished, taking out the cathode plate, washing the cathode plate by using deionized water, and drying the cathode plate in a 60-degree drying oven for 6 hours. The obtained carbon-supported nickel-iron double-metal hydroxide catalyst is used as a cathode plate, a commercial Pt sheet electrode is adopted as an anode plate, ag/AgCl (saturated KCl solution as filling liquid) is adopted as a reference electrode, 30mL of 0.1M KNO is filled in a cathode pool 3 The mixture was mixed with 0.1M KOH and the anode was charged with 30mL of 0.1M KOH solution. Turn on the gas switch for 10mL min -1 Continuously introducing high-purity argon at the flow rate, opening a power switch of the electrochemical workstation after 30min, and setting the electrolytic voltage to be-1.3V for continuous reaction. After the reaction, the cathode pool electrolyte was collected, the ammonia concentration of the reacted electrolyte was detected by indophenol blue spectrophotometry and an ammonia sensitive electrode, and the faradaic efficiency and ammonia yield were calculated, the results are shown in fig. 3. As can be seen, when the nickel-iron ratio of the electrodeposition liquid is 2:1 hour, ni prepared 2 Fe 1 LDH/CC can reach 80% of Faraday efficiency81nmol s -1 cm -2 The ammonia yield of (a).
Example 4 (deposition time 0 min)
The invention researches different loading amounts of the carbon-loaded nickel-iron double-metal hydroxide catalyst on NO 3 Effect of RR performance. The specific operation is as follows: nickel nitrate hexahydrate, ferric nitrate nonahydrate, ammonium fluoride and urea (the concentrations are 0.6mM, 0.2mM, 1.6mM and 4mM respectively) are rapidly and uniformly stirred by a magnetic stirrer to obtain a mixed solution, the mixed solution is added into the pre-assembled electrodeposition tank, and the electrodeposition is carried out for 0min by adopting a constant temperature and constant pressure (the voltage is set to be-1V, and the temperature is set to be 25 ℃ and constant temperature). And after the reaction is finished, taking out the cathode plate, washing the cathode plate by using deionized water, and drying the cathode plate in a 60-degree drying oven for 6 hours. The obtained carbon-supported nickel-iron double-metal hydroxide catalyst is used as a cathode plate, a commercial Pt sheet electrode is adopted as an anode plate, ag/AgCl (saturated KCl solution as filling liquid) is adopted as a reference electrode, 30mL of 0.1M KNO is filled in a cathode pool 3 The mixture was mixed with 0.1M KOH and the anode was charged with 30mL of 0.1M KOH solution. Turn on the gas switch for 10mL min -1 Continuously introducing high-purity argon at the flow rate, opening a power switch of the electrochemical workstation after 30min, and setting the electrolytic voltage to-0.6V for continuous reaction. After the reaction, the cathode cell electrolyte was collected, and the ammonia concentration of the electrolyte after the reaction was detected by indophenol blue spectrophotometry and an ammonia gas sensitive electrode, and the faradaic efficiency and ammonia yield were calculated, the results of which are shown in fig. 2. When the deposition time was 0min, the catalyst loading was 0mg cm -2 After the reaction was completed, the ammonia concentration in the electrolyte was 5.4mg/L, and the Faraday efficiency was 10%.
Example 5 (deposition time 5 min)
The invention researches different loading amounts of the carbon-loaded nickel-iron double-metal hydroxide catalyst on NO 3 Effect of RR performance. The specific operation is as follows: rapidly stirring nickel nitrate hexahydrate, ferric nitrate nonahydrate, ammonium fluoride and urea (concentration of 0.6mM, 0.2mM, 1.6mM and 4mM respectively) with a magnetic stirrer to obtain a mixed solution, adding the mixed solution into the pre-assembled electrodeposition tank, and performing electrodeposition for 5min by adopting a constant temperature and constant pressure (voltage is set to-1V and temperature is 25 deg.C)And (4) reacting. And after the reaction is finished, taking out the cathode plate, washing the cathode plate by using deionized water, and drying the cathode plate in a 60-degree oven for 6 hours. The obtained carbon-supported nickel-iron double-metal hydroxide catalyst is used as a cathode plate, a commercial Pt sheet electrode is adopted as an anode plate, ag/AgCl (saturated KCl solution as filling liquid) is adopted as a reference electrode, 30mL of 0.1M KNO is filled in a cathode pool 3 The mixture was mixed with 0.1M KOH and the anode was charged with 30mL of 0.1M KOH solution. Turn on the gas switch for 10mL min -1 Continuously introducing high-purity argon at the flow rate, opening a power switch of the electrochemical workstation after 30min, and setting the electrolytic voltage to-0.6V for continuous reaction. After the reaction, the cathode cell electrolyte was collected, and the ammonia concentration of the electrolyte after the reaction was detected by indophenol blue spectrophotometry and an ammonia gas sensitive electrode, and the faradaic efficiency and ammonia yield were calculated, the results of which are shown in fig. 2. With the increase of time, the adhesion amount of the catalyst on the surface of the hydrophilic carbon paper is from 0mg cm -2 Rising to 7mg cm -2 However, the catalytic performance was increased and then decreased at 0.4mg cm -2 The faradaic efficiency and ammonia concentration reached 43% and 55mg/L, respectively, and then dropped to 19% and 9.7mg/L, respectively, to the best. Therefore, the optimal loading capacity of the carbon-supported nickel-iron double-metal hydroxide electrocatalyst for synthesizing ammonia is 0.4mg cm -2 。
Example 6 (deposition time 60 min)
The invention researches different loading amounts of the carbon-loaded nickel-iron double-metal hydroxide catalyst on NO 3 Impact of RR performance. The specific operation is as follows: uniformly and rapidly stirring nickel nitrate hexahydrate, ferric nitrate nonahydrate, ammonium fluoride and urea (the concentrations are 0.6mM, 0.2mM, 1.6mM and 4mM respectively) by using a magnetic stirrer to obtain a mixed solution, adding the mixed solution into the pre-assembled electrodeposition tank, and carrying out electrodeposition reaction for 60min by adopting a constant temperature and constant pressure (the voltage is set to be-1V, and the temperature is set to be 25 ℃ and constant temperature). And after the reaction is finished, taking out the cathode plate, washing the cathode plate by using deionized water, and drying the cathode plate in a 60-degree oven for 6 hours. The carbon-supported nickel-iron double metal hydroxide catalyst obtained above was used as a cathode plate, a commercial Pt sheet electrode was used as an anode plate, ag/AgCl (saturated KCl solution as a filling solution) was used as a reference electrode, and 30mL of 0.1M KNO was charged in a cathode cell 3 Mixing the solution with 0.1M KOH, and then,the anode was charged with 30mL of 0.1M KOH solution. Turn on the gas switch for 10mL min -1 Continuously introducing high-purity argon at the flow rate, opening a power switch of the electrochemical workstation after 30min, and setting the electrolysis voltage to-0.6V for continuous reaction. After the reaction, the cathode cell electrolyte was collected, and the ammonia concentration of the electrolyte after the reaction was detected by indophenol blue spectrophotometry and an ammonia gas sensitive electrode, and the faradaic efficiency and ammonia yield were calculated, the results of which are shown in fig. 2. When the deposition time was 60min, the catalyst loading was 7mg cm -2 After the reaction is finished, the concentration of electrolytic liquid ammonia is 13.5mg/L, and the Faraday efficiency is 18 percent.
Example 7 (in this example, the above voltage is 0.6 to 2.3, point value is-1.1V)
The invention researches different loading amounts of the carbon-loaded nickel-iron double-metal hydroxide catalyst on NO 3 Impact of RR performance. The specific operation is as follows: nickel nitrate hexahydrate, ferric nitrate nonahydrate, ammonium fluoride and urea (the concentrations are 0.6mM, 0.2mM, 2mM and 4mM respectively) are rapidly and uniformly stirred by a magnetic stirrer to obtain a mixed solution, the mixed solution is added into the pre-assembled electrodeposition tank, and the electrodeposition is carried out for 5min by adopting a constant temperature and constant pressure (the voltage is set to be-1V, and the temperature is set to be 25 ℃ and constant temperature). And after the reaction is finished, taking out the cathode plate, washing the cathode plate by using deionized water, and drying the cathode plate in a 60-degree oven for 6 hours. The obtained carbon-supported nickel-iron double-metal hydroxide catalyst is used as a cathode plate, a commercial Pt sheet electrode is adopted as an anode plate, ag/AgCl (saturated KCl solution as filling liquid) is adopted as a reference electrode, 30mL of 0.1M KNO is filled in a cathode pool 3 The solution was mixed with 0.1M KOH and the anode was charged with 30mL of 0.1M KOH solution. Turn on the gas switch for 10mL min -1 Continuously introducing high-purity argon at the flow rate, opening a power switch of the electrochemical workstation after 30min, and setting the electrolysis voltage to-1.1V for continuous reaction. After the reaction, the cathode pool electrolyte was collected, the ammonia concentration of the reacted electrolyte was detected by indophenol blue spectrophotometry and an ammonia sensitive electrode, and the faradaic efficiency and ammonia yield were calculated, the results are shown in fig. 3. As can be seen, at-1.1V the Faraday efficiency and ammonia yield reached close to 100% and 150nmol s, respectively -1 cm -2 And as the electrolytic voltage increases, the ammonia yield does not change much, but becauseThe hydrogen evolution competition reaction is severe, and the Faraday efficiency is slightly reduced. The results show that higher yields and maximum faradaic efficiency regime can be achieved when the reaction is run at-1.1V.
Example 8 (the above voltage is-0.6 to-2.3, point value is-0.6V)
The invention researches different loading amounts of the carbon-loaded nickel-iron double-metal hydroxide catalyst on NO 3 Impact of RR performance. The specific operation is as follows: nickel nitrate hexahydrate, ferric nitrate nonahydrate, ammonium fluoride and urea (the concentrations are 0.6mM, 0.2mM, 1mM and 4mM respectively) are rapidly and uniformly stirred by a magnetic stirrer to obtain a mixed solution, the mixed solution is added into the pre-assembled electrodeposition tank, and the electrodeposition is carried out for 5min by adopting a constant temperature and constant pressure (the voltage is set to be-1V, and the temperature is set to be 25 ℃ and constant temperature). And after the reaction is finished, taking out the cathode plate, washing the cathode plate by using deionized water, and drying the cathode plate in a 60-degree drying oven for 6 hours. The carbon-supported nickel-iron double metal hydroxide catalyst obtained above was used as a cathode plate, a commercial Pt sheet electrode was used as an anode plate, ag/AgCl (saturated KCl solution as a filling solution) was used as a reference electrode, and 30mL of 0.1M KNO was charged in a cathode cell 3 The solution was mixed with 0.1M KOH and the anode was charged with 30mL of 0.1M KOH solution. Turn on the gas switch for 10mL min -1 Continuously introducing high-purity argon at the flow rate, opening a power switch of the electrochemical workstation after 30min, and setting the electrolytic voltage to-0.6V for continuous reaction. After the reaction, the cathode pool electrolyte was collected, the ammonia concentration of the reacted electrolyte was detected by indophenol blue spectrophotometry and an ammonia sensitive electrode, and the faradaic efficiency and ammonia yield were calculated, the results are shown in fig. 3. As can be seen, at-0.6V the Faraday efficiencies and ammonia yields reached close to 100% and 47nmol s, respectively -1 cm -2 。
Example 9 (this example is the above voltage 0.6-2.3, point value-2.3V)
The invention researches different loading amounts of the carbon-loaded nickel-iron double-metal hydroxide catalyst on NO 3 Impact of RR performance. The specific operation is as follows: rapidly stirring nickel sulfate, ferric sulfate, ammonium fluoride and sodium hydroxide (concentration of 0.6mM, 0.2mM, 1.6mM and 4mM respectively) with magnetic stirrer to obtain mixed solution, and mixing the mixed solutionAdding the solution into the above pre-assembled electrodeposition tank, and performing electrodeposition for 5min at constant temperature and constant voltage (voltage is-1V and temperature is 25 deg.C). And after the reaction is finished, taking out the cathode plate, washing the cathode plate by using deionized water, and drying the cathode plate in a 60-degree drying oven for 6 hours. The obtained carbon-supported nickel-iron double-metal hydroxide catalyst is used as a cathode plate, a commercial Pt sheet electrode is adopted as an anode plate, ag/AgCl (saturated KCl solution as filling liquid) is adopted as a reference electrode, 30mL of 0.1M KNO is filled in a cathode pool 3 The mixture was mixed with 0.1M KOH and the anode was charged with 30mL of 0.1M KOH solution. Turn on the gas switch for 10mL min -1 Continuously introducing high-purity argon at the flow rate, opening a power switch of the electrochemical workstation after 30min, and setting the electrolytic voltage to be-2.3V for continuous reaction. After the reaction, the cathode pool electrolyte was collected, the ammonia concentration of the reacted electrolyte was detected by indophenol blue spectrophotometry and an ammonia sensitive electrode, and the faradaic efficiency and ammonia yield were calculated, the results are shown in fig. 3. As can be seen, at-2.3V the Faraday efficiency and ammonia yield reached nearly 91% and 188nmol s, respectively -1 cm -2 。
Example 10 (this example is 1mM of the above-mentioned 1-3009mM electrolyte concentration point)
The concentration of the carbon-supported nickel-iron double-metal hydroxide catalyst electrolyte shown in the invention is researched to NO 3 Impact of RR performance. The specific operation is as follows: nickel acetate, ferric chloride, ammonium fluoride and urea (the concentrations are 0.6mM, 0.2mM, 1.6mM and 4mM respectively) are rapidly and uniformly stirred by a magnetic stirrer to obtain a mixed solution, the mixed solution is added into the pre-assembled electrodeposition cell, and the electrodeposition is carried out for 5min by adopting a constant temperature and constant pressure (the voltage is set to be-1V, and the temperature is set to be 25 ℃ and constant temperature). And after the reaction is finished, taking out the cathode plate, washing the cathode plate by using deionized water, and drying the cathode plate in a 60-degree drying oven for 6 hours. The carbon-supported nickel-iron double metal hydroxide catalyst obtained above was used as a cathode plate, a commercial Pt sheet electrode was used as an anode plate, ag/AgCl (saturated KCl solution as a filling solution) was used as a reference electrode, and 30mL of 1mM KNO was charged in a cathode cell 3 The mixture was mixed with 0.1M KOH and the anode was charged with 30mL of 0.1M KOH solution. Turn on the gas switch for 10mL min -1 Continuously introducing high-purity argon at a flow rate, and opening the electrochemistry after 30minAnd a workstation power switch for setting the electrolysis voltage to-1.1V for continuous reaction. After the reaction, the cathode cell electrolyte was collected, and the ammonia concentration of the electrolyte after the reaction was detected by indophenol blue spectrophotometry and an ammonia gas sensitive electrode, and the faradaic efficiency and ammonia yield were calculated, the results of which are shown in fig. 3. As can be seen from the figure, when KNO 3 When the concentration is 1mM, the Faraday efficiency reaches 7 percent, and the ammonia yield reaches 38nmol s -1 cm -2 。
Example 11 (this example is the above-mentioned 1-3009mM electrolyte concentration point value of 1000 mM)
The concentration of the carbon-supported nickel-iron double-metal hydroxide catalyst electrolyte shown in the invention is researched to NO 3 Effect of RR performance. The specific operation is as follows: rapidly and uniformly stirring nickel acetate, iron acetate, ammonium fluoride and sodium hydroxide (the concentrations are 0.6mM, 0.2mM, 1.6mM and 4mM respectively) by using a magnetic stirrer to obtain a mixed solution, adding the mixed solution into the pre-assembled electrodeposition tank, and carrying out electrodeposition for 5min by adopting a constant temperature and constant pressure (the voltage is set to be minus 2V, and the temperature is set to be 25 ℃ and constant temperature). And after the reaction is finished, taking out the cathode plate, washing the cathode plate by using deionized water, and drying the cathode plate in a 60-degree drying oven for 6 hours. The carbon-supported nickel-iron double metal hydroxide catalyst obtained above is used as a cathode plate, a commercial Pt sheet electrode is adopted as an anode plate, ag/AgCl (saturated KCl solution as a filling solution) is adopted as a reference electrode, 30mL of 1000mM KNO is filled in a cathode pool 3 The solution was mixed with 0.1M KOH and the anode was charged with 30mL of 0.1M KOH solution. Turn on the gas switch for 10mL min -1 Continuously introducing high-purity argon at the flow rate, opening a power switch of the electrochemical workstation after 30min, and setting the electrolytic voltage to-1.1V for continuous reaction. After the reaction, the cathode cell electrolyte was collected, and the ammonia concentration of the electrolyte after the reaction was detected by indophenol blue spectrophotometry and an ammonia gas sensitive electrode, and the faradaic efficiency and ammonia yield were calculated, the results of which are shown in fig. 3. As can be seen, the Faraday efficiency increases with the increasing electrolyte concentration, the ammonia yield increases from 1mM to 1000mM, and when KNO is used 3 The Faraday efficiency reaches nearly 100% at a concentration of 1000mM, and the ammonia yield reaches 142nmol s -1 cm -2 。
Example 12 (this example is the above-mentioned 1-3009mM electrolyte concentration point value is saturated potassium nitrate solution)
The concentration of the carbon-supported nickel-iron double-metal hydroxide catalyst electrolyte shown in the invention is researched to NO 3 Effect of RR performance. The specific operation is as follows: nickel nitrate hexahydrate, ferric nitrate nonahydrate, ammonium fluoride and urea (the concentrations are 0.6mM, 0.2mM, 1.6mM and 4mM respectively) are rapidly and uniformly stirred by a magnetic stirrer to obtain a mixed solution, the mixed solution is added into the pre-assembled electrodeposition tank, and the electrodeposition is carried out for 5min by adopting a constant temperature and constant pressure (the voltage is set to be-1V, and the temperature is set to be 25 ℃ and constant temperature). And after the reaction is finished, taking out the cathode plate, washing the cathode plate by using deionized water, and drying the cathode plate in a 60-degree drying oven for 6 hours. The obtained carbon-supported nickel-iron double-metal hydroxide catalyst is used as a cathode plate, a commercial Pt sheet electrode is adopted as an anode plate, ag/AgCl (saturated KCl solution as filling liquid) is adopted as a reference electrode, and 30mL of saturated KNO is filled in a cathode pool 3 The solution was mixed with 0.1M KOH and the anode was charged with 30mL of 0.1M KOH solution. Turn on the gas switch for 10mL min -1 Continuously introducing high-purity argon at the flow rate, opening a power switch of the electrochemical workstation after 30min, and setting the electrolytic voltage to-1.1V for continuous reaction. After the reaction, the cathode cell electrolyte was collected, and the ammonia concentration of the electrolyte after the reaction was detected by indophenol blue spectrophotometry and an ammonia gas sensitive electrode, and the faradaic efficiency and ammonia yield were calculated, the results of which are shown in fig. 3. As can be seen, the Faraday efficiency increased with increasing electrolyte concentration, the ammonia yield increased from 1mM to 1000mM, but decreased to 101.69nmol s in saturated potassium nitrate solution -1 cm -2 The faraday efficiency is close to 100%. Therefore, the optimal application concentration of the carbon-supported nickel-iron double-metal hydroxide catalyst for synthesizing ammonia is 1000mM.
Example 13 (blank control in this example)
The invention discloses a method for researching the metal load pair NO of the carbon-loaded nickel-iron double-metal hydroxide catalyst 3 Impact of RR performance. The specific operation is as follows: the hydrophilic carbon paper without the above electrodeposition was used as the cathode plate, the commercial Pt plate electrode was used as the anode plate, ag/AgCl (saturated KCl solution as the filling solution) was used as the reference electrode, and the cathode cell was filled with30mL 0.1M KNO 3 The solution was mixed with 0.1M KOH and the anode was charged with 30mL of 0.1M KOH solution. Turn on the gas switch for 10mL min -1 Continuously introducing high-purity argon at the flow rate, opening a power switch of the electrochemical workstation after 30min, and setting the electrolytic voltage to-1.1V for continuous reaction. After the reaction, the cathode cell electrolyte was collected, and the ammonia concentration of the electrolyte after the reaction was detected by indophenol blue spectrophotometry and an ammonia gas sensitive electrode, and the faradaic efficiency and ammonia yield were calculated, the results of which are shown in fig. 3. As can be seen, the hydrophilic carbon paper without the deposited nickel iron metal oxide had a Faraday efficiency of 53% and an ammonia yield of 42nmol s -1 cm -2 The nickel-iron ratio is 3:1 the faradaic efficiency of the carbon-supported nickel-iron double-metal hydroxide electrocatalyst is 90%, and the ammonia yield is 78nmol s -1 cm -2 Is significantly higher than that of hydrophilic carbon paper. Therefore, the doping of the nickel-iron metal is beneficial to improving the catalytic activity of the hydrophilic carbon paper.
The above-mentioned embodiments only express the embodiments of the present invention, but not should be understood as the limitation of the scope of the invention patent, it should be noted that, for those skilled in the art, many variations and modifications can be made without departing from the concept of the present invention, and these all fall into the protection scope of the present invention.
Claims (7)
1. An electrochemical preparation method of a carbon-supported nickel-iron double-metal hydroxide catalyst for synthesizing ammonia by electro-reduction of nitrate is characterized by comprising the following steps:
step 1, respectively dissolving nickel nitrate hexahydrate, ferric nitrate nonahydrate, ammonium fluoride and urea in deionized water, and rapidly and uniformly stirring by using a magnetic stirrer to obtain a mixed solution;
step 2, taking the electrode sandwiched with the hydrophilic carbon paper as a cathode plate, taking a commercial platinum sheet electrode as an anode plate, and assembling a reference electrode which is Ag/AgCl and an electrochemical workstation into an electrodeposition tank;
step 3, adding the mixed solution into a pre-assembled electrodeposition tank, setting the voltage to be in the range of-1V to-2V, keeping the temperature at 25 ℃ and carrying out electrodeposition reaction in a constant-voltage mode, wherein the reaction time is not more than 60min; and after the reaction is finished, taking out the cathode plate, washing the cathode plate by using deionized water, putting the cathode plate into an oven, drying the cathode plate, and taking out the cathode plate to obtain the carbon-coupled nickel-iron-based electrocatalyst.
2. The preparation method of the carbon-coupled nickel-iron-based catalyst for synthesizing ammonia by electrocatalytic nitrate reduction is characterized in that the concentrations of nickel nitrate hexahydrate, ferric nitrate nonahydrate, ammonium fluoride and urea in the mixed solution in the step 1 are 0.4-0.8mM,0.2mM,1-2mM and 4mM respectively.
3. The method for preparing the carbon-coupled nickel-iron-based catalyst for synthesizing ammonia by electrocatalytic nitrate reduction as recited in claim 2, wherein the nickel nitrate hexahydrate in the step 1 can be replaced by nickel sulfate or nickel acetate.
4. The method for preparing the carbon-coupled nickel-iron-based catalyst for synthesizing ammonia by electrocatalytic nitrate reduction as defined in claim 2, wherein the ferric nitrate nonahydrate in the step 1 can be replaced by ferric sulfate, ferric acetate or ferric chloride.
5. The method for preparing the carbon-coupled nickel-iron-based catalyst for synthesizing ammonia by electrocatalytic nitrate reduction as recited in claim 2, wherein the ammonium fluoride in the step 1 can be replaced by ammonium bifluoride, sodium fluoride, sodium chloride or ammonium chloride.
6. The method for preparing the carbon-coupled nickel-iron-based catalyst for synthesizing ammonia by electrocatalytic nitrate reduction as set forth in claim 2, wherein the urea in the step 1 can be replaced by sodium hydroxide.
7. The application of the carbon-coupled nickel-iron-based catalyst for synthesizing ammonia by electrocatalytic nitrate reduction obtained by the preparation method of any one of claims 1 to 6 is characterized in that the carbon-coupled nickel-iron-based electrocatalyst is cut into thin slices to be used as a cathode plate, a commercial platinum sheet electrode is used as an anode plate, and a reference electrode is Ag/AgCl and is assembled into a three-layer structureH-type electrolytic cell of electrode system, cathode filled with KNO 3 Adding KOH solution of the same amount into the anode of the mixed solution of KOH and KOH, and assembling into a reaction tank; and opening a gas switch, continuously introducing high-purity argon, then opening a power switch of the electrochemical workstation, and setting the voltage to be-0.6V to-2.3V for continuous electrolysis for 1-4 h.
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Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106011911A (en) * | 2016-05-26 | 2016-10-12 | 重庆大学 | Method of partial vulcanization to improve oxygen evolution electrode performance of metal hydroxide |
| CN110947387A (en) * | 2019-11-25 | 2020-04-03 | 中国工程物理研究院材料研究所 | Preparation method and application of nickel-iron double metal hydroxide nano film material |
| CN111569884A (en) * | 2020-05-27 | 2020-08-25 | 上海科技大学 | Ni-Fe catalyst and preparation method and application thereof |
| CN111701593A (en) * | 2020-07-02 | 2020-09-25 | 济南大学 | Preparation of lithium-iron layered double-metal hydroxide catalyst and application of lithium-iron layered double-metal hydroxide catalyst in electrocatalytic nitrogen reduction |
| CN111905744A (en) * | 2020-07-23 | 2020-11-10 | 安徽工业大学 | Nickel-iron hydroxide composite material, catalyst, preparation method and application |
| CN113926456A (en) * | 2021-09-14 | 2022-01-14 | 杭州师范大学 | Preparation method and application of NiFe-LDH catalyst for reducing nitrate radical into ammonia |
| CN114540831A (en) * | 2021-11-30 | 2022-05-27 | 上海科技大学 | Nickel-iron bimetal coordination polymer catalyst for water electrolysis and preparation method thereof |
| CN114686917A (en) * | 2022-04-11 | 2022-07-01 | 天津大学 | Electro-catalytic catalyst for synthesizing ammonia by reducing nitrate, preparation method and application thereof |
-
2022
- 2022-12-22 CN CN202211658014.3A patent/CN115786959A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106011911A (en) * | 2016-05-26 | 2016-10-12 | 重庆大学 | Method of partial vulcanization to improve oxygen evolution electrode performance of metal hydroxide |
| CN110947387A (en) * | 2019-11-25 | 2020-04-03 | 中国工程物理研究院材料研究所 | Preparation method and application of nickel-iron double metal hydroxide nano film material |
| CN111569884A (en) * | 2020-05-27 | 2020-08-25 | 上海科技大学 | Ni-Fe catalyst and preparation method and application thereof |
| CN111701593A (en) * | 2020-07-02 | 2020-09-25 | 济南大学 | Preparation of lithium-iron layered double-metal hydroxide catalyst and application of lithium-iron layered double-metal hydroxide catalyst in electrocatalytic nitrogen reduction |
| CN111905744A (en) * | 2020-07-23 | 2020-11-10 | 安徽工业大学 | Nickel-iron hydroxide composite material, catalyst, preparation method and application |
| CN113926456A (en) * | 2021-09-14 | 2022-01-14 | 杭州师范大学 | Preparation method and application of NiFe-LDH catalyst for reducing nitrate radical into ammonia |
| CN114540831A (en) * | 2021-11-30 | 2022-05-27 | 上海科技大学 | Nickel-iron bimetal coordination polymer catalyst for water electrolysis and preparation method thereof |
| CN114686917A (en) * | 2022-04-11 | 2022-07-01 | 天津大学 | Electro-catalytic catalyst for synthesizing ammonia by reducing nitrate, preparation method and application thereof |
Non-Patent Citations (2)
| Title |
|---|
| YANG YANG ET AL.: "Highly Active Trimetallic NiFeCr Layered Double Hydroxide Electrocatalysts for Oxygen Evolution Reaction", 《ADV. ENERGY MATER.》, vol. 8, 1 February 2018 (2018-02-01), pages 1703189 * |
| 李海金;韩秋彤;贾虎;周勇;邹志刚;: "LDHs材料的制备及光催化应用研究进展", 中国材料进展, no. 02, 8 March 2019 (2019-03-08), pages 91 - 98 * |
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