CN115261909A - Keggin type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material, preparation method and application thereof - Google Patents
Keggin type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material, preparation method and application thereof Download PDFInfo
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- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 title claims abstract description 189
- 239000011964 heteropoly acid Substances 0.000 title claims abstract description 163
- 229910002092 carbon dioxide Inorganic materials 0.000 title claims abstract description 126
- 230000009467 reduction Effects 0.000 title claims abstract description 95
- 239000001569 carbon dioxide Substances 0.000 title claims abstract description 94
- 239000000463 material Substances 0.000 title claims abstract description 92
- 238000002360 preparation method Methods 0.000 title claims abstract description 48
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 claims abstract description 41
- 239000003792 electrolyte Substances 0.000 claims abstract description 31
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 29
- 229910052720 vanadium Inorganic materials 0.000 claims abstract description 25
- LEONUFNNVUYDNQ-UHFFFAOYSA-N vanadium atom Chemical group [V] LEONUFNNVUYDNQ-UHFFFAOYSA-N 0.000 claims abstract description 25
- 239000000243 solution Substances 0.000 claims description 164
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims description 58
- 239000000047 product Substances 0.000 claims description 47
- XLYOFNOQVPJJNP-ZSJDYOACSA-N heavy water Substances [2H]O[2H] XLYOFNOQVPJJNP-ZSJDYOACSA-N 0.000 claims description 37
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 claims description 33
- 238000006243 chemical reaction Methods 0.000 claims description 29
- 239000007864 aqueous solution Substances 0.000 claims description 26
- 238000000034 method Methods 0.000 claims description 21
- 238000003756 stirring Methods 0.000 claims description 21
- 238000005868 electrolysis reaction Methods 0.000 claims description 19
- 150000001450 anions Chemical class 0.000 claims description 17
- 229910052738 indium Inorganic materials 0.000 claims description 15
- 239000012153 distilled water Substances 0.000 claims description 14
- 238000001035 drying Methods 0.000 claims description 14
- APFVFJFRJDLVQX-UHFFFAOYSA-N indium atom Chemical compound [In] APFVFJFRJDLVQX-UHFFFAOYSA-N 0.000 claims description 14
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 claims description 12
- 239000008367 deionised water Substances 0.000 claims description 12
- 229910021641 deionized water Inorganic materials 0.000 claims description 12
- 239000002243 precursor Substances 0.000 claims description 11
- 229910019501 NaVO3 Inorganic materials 0.000 claims description 10
- CMZUMMUJMWNLFH-UHFFFAOYSA-N sodium metavanadate Chemical compound [Na+].[O-][V](=O)=O CMZUMMUJMWNLFH-UHFFFAOYSA-N 0.000 claims description 10
- 229910015667 MoO4 Inorganic materials 0.000 claims description 9
- 229910004619 Na2MoO4 Inorganic materials 0.000 claims description 8
- 238000001953 recrystallisation Methods 0.000 claims description 8
- 239000011684 sodium molybdate Substances 0.000 claims description 8
- TVXXNOYZHKPKGW-UHFFFAOYSA-N sodium molybdate (anhydrous) Chemical compound [Na+].[Na+].[O-][Mo]([O-])(=O)=O TVXXNOYZHKPKGW-UHFFFAOYSA-N 0.000 claims description 8
- 239000000126 substance Substances 0.000 claims description 8
- 229910021607 Silver chloride Inorganic materials 0.000 claims description 7
- 238000005341 cation exchange Methods 0.000 claims description 7
- 238000000605 extraction Methods 0.000 claims description 7
- 239000012528 membrane Substances 0.000 claims description 7
- HKZLPVFGJNLROG-UHFFFAOYSA-M silver monochloride Chemical compound [Cl-].[Ag+] HKZLPVFGJNLROG-UHFFFAOYSA-M 0.000 claims description 7
- 239000007832 Na2SO4 Substances 0.000 claims description 6
- 229910020350 Na2WO4 Inorganic materials 0.000 claims description 6
- 229910000147 aluminium phosphate Inorganic materials 0.000 claims description 6
- -1 ether compound Chemical class 0.000 claims description 6
- 239000000203 mixture Substances 0.000 claims description 6
- 229910052938 sodium sulfate Inorganic materials 0.000 claims description 6
- XMVONEAAOPAGAO-UHFFFAOYSA-N sodium tungstate Chemical compound [Na+].[Na+].[O-][W]([O-])(=O)=O XMVONEAAOPAGAO-UHFFFAOYSA-N 0.000 claims description 6
- 238000001291 vacuum drying Methods 0.000 claims description 6
- 238000005303 weighing Methods 0.000 claims description 6
- 238000001704 evaporation Methods 0.000 claims description 4
- 239000002244 precipitate Substances 0.000 claims description 4
- AJPJDKMHJJGVTQ-UHFFFAOYSA-M sodium dihydrogen phosphate Chemical compound [Na+].OP(O)([O-])=O AJPJDKMHJJGVTQ-UHFFFAOYSA-M 0.000 claims description 4
- 229910000162 sodium phosphate Inorganic materials 0.000 claims description 4
- 230000008020 evaporation Effects 0.000 claims description 3
- 238000000967 suction filtration Methods 0.000 claims description 3
- 238000009423 ventilation Methods 0.000 claims description 3
- 238000002156 mixing Methods 0.000 claims description 2
- 238000006722 reduction reaction Methods 0.000 abstract description 91
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 abstract description 16
- 239000007791 liquid phase Substances 0.000 abstract description 16
- 238000004519 manufacturing process Methods 0.000 abstract description 6
- 239000002904 solvent Substances 0.000 abstract description 3
- 231100000956 nontoxicity Toxicity 0.000 abstract description 2
- 239000003960 organic solvent Substances 0.000 abstract description 2
- 239000012071 phase Substances 0.000 abstract description 2
- 239000007789 gas Substances 0.000 description 15
- 238000002484 cyclic voltammetry Methods 0.000 description 12
- 229960000583 acetic acid Drugs 0.000 description 11
- 239000001257 hydrogen Substances 0.000 description 11
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 10
- 229910052739 hydrogen Inorganic materials 0.000 description 10
- 238000001228 spectrum Methods 0.000 description 10
- 238000010586 diagram Methods 0.000 description 8
- 238000004817 gas chromatography Methods 0.000 description 8
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 5
- 229910052698 phosphorus Inorganic materials 0.000 description 5
- 239000011574 phosphorus Substances 0.000 description 5
- 239000007787 solid Substances 0.000 description 5
- 230000003197 catalytic effect Effects 0.000 description 4
- 150000001875 compounds Chemical class 0.000 description 4
- 238000011160 research Methods 0.000 description 4
- 238000012360 testing method Methods 0.000 description 4
- 238000002441 X-ray diffraction Methods 0.000 description 3
- 239000002253 acid Substances 0.000 description 3
- 150000007513 acids Chemical class 0.000 description 3
- 230000008859 change Effects 0.000 description 3
- 239000013078 crystal Substances 0.000 description 3
- 230000033116 oxidation-reduction process Effects 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 230000009471 action Effects 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 150000001735 carboxylic acids Chemical class 0.000 description 2
- 239000012141 concentrate Substances 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000005265 energy consumption Methods 0.000 description 2
- BDAGIHXWWSANSR-UHFFFAOYSA-N formic acid Substances OC=O BDAGIHXWWSANSR-UHFFFAOYSA-N 0.000 description 2
- 239000002803 fossil fuel Substances 0.000 description 2
- 239000000446 fuel Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 2
- 229910052721 tungsten Inorganic materials 0.000 description 2
- 239000010937 tungsten Substances 0.000 description 2
- 238000010792 warming Methods 0.000 description 2
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 1
- 239000005977 Ethylene Substances 0.000 description 1
- BEWZPBWLGIPWFP-UHFFFAOYSA-N [V].P(=O)(=O)[Mo] Chemical group [V].P(=O)(=O)[Mo] BEWZPBWLGIPWFP-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000004177 carbon cycle Methods 0.000 description 1
- 238000006555 catalytic reaction Methods 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000002848 electrochemical method Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 239000012362 glacial acetic acid Substances 0.000 description 1
- 239000005431 greenhouse gas Substances 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 239000002608 ionic liquid Substances 0.000 description 1
- 239000005486 organic electrolyte Substances 0.000 description 1
- 230000020477 pH reduction Effects 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000010992 reflux Methods 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 230000001988 toxicity Effects 0.000 description 1
- 231100000419 toxicity Toxicity 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 238000009901 transfer hydrogenation reaction Methods 0.000 description 1
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- 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
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- 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
- C25B1/23—Carbon monoxide or syngas
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- 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
- C25B3/00—Electrolytic production of organic compounds
- C25B3/01—Products
- C25B3/07—Oxygen containing compounds
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- 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
- C25B3/00—Electrolytic production of organic compounds
- C25B3/20—Processes
- C25B3/25—Reduction
- C25B3/26—Reduction of carbon dioxide
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- Chemical Kinetics & Catalysis (AREA)
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- Materials Engineering (AREA)
- Metallurgy (AREA)
- Inorganic Chemistry (AREA)
- Inorganic Compounds Of Heavy Metals (AREA)
Abstract
A Keggin type vanadium substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material, a preparation method and application thereof belong to electrocatalysis of CO2Reduction to CO and C2+The technical field of liquid phase products. The invention aims to solve the problem that the prior heteropoly acid electrocatalytic carbon dioxide reduction material is mostly limited to a binary or ternary system in an organic solvent, and C2+The Faraday efficiency of the product is not high. The vanadium substituted quaternary heteropoly acid prepared by the invention comprises PVMoW10O40Or PV2MoW9O40(ii) a The prepared heteropoly acid is dissolved in solvent water and then used as electrolyte to carry out CO in an electrolytic cell2Reduction reaction to obtain gas phase products of CO and C2+Liquid phase products acetic acid and ethanol. The invention applies quaternary heteropoly acid to catalyzing CO for the first time2The reduction reaction has simple production steps, simple operation, no toxicity and no pollution, and the total Faraday efficiency of the prepared liquid phase product can reach 95 percent.
Description
Technical Field
The invention belongs to electrocatalysis of CO2Reduction to CO and C2+The technical field of liquid phase products; in particular to a Keggin type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material, a preparation method and application thereof.
Background
Due to large amount of artificial CO2The excessive consumption of fossil fuels seriously interferes with the balance of natural carbon cycle, causing global warming and energy crisis problems. Carbon dioxide, as a major component of greenhouse gases, is the "main cause" of global warming. However, in the next decades, conventional fossil fuels will continue to be a major form of energy and cannot be completely replaced for a short period of time. From the sustainable development point of view, effective measures are adopted to realize the immobilization of carbon resources and CO is immobilized2Direct conversion to fuels or chemicals is a more potentially valuable process. In the past decades, scientists have employed photochemical reduction, electrochemical reduction, and catalytic transfer hydrogenation. Compared to these methods, the electrocatalytic reduction of CO2(CO2RR) provides a more effective way for developing and utilizing novel energy, and CO2RR will become atmospheric CO2To more efficient strategies for fuels and chemicals with high added value.
Compared with the electrocatalytic reduction of CO2CO, hydrocarbons and C such as formic acid1Products, ethylene, acetic acid and ethanol, etc. C2+The product has higher energy density and added value, thus being more favored by researchers. But electrocatalytic conversion of carbon dioxide to C2+The product involves a difficult multi-proton-multi-electron transfer, C-C coupling step, resulting in C2+The yield of the product is low. How to increase C under the existing current density2+The faradaic efficiency of the product is currently CO2Electrocatalytic reduction research is one of the key problems to be solved urgently.
Disclosure of Invention
The invention aims to provide a method for improving C2+Green and environment-friendly Keggin type vanadium-substituted quaternary heteropoly acid preparation method of product with Faraday efficiency and electrocatalysis of CO2Reduction to CO and C2+Application of liquid phase product.
In order to realize the purpose, the invention is realized by the following technical scheme:
a preparation method of a Keggin type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material comprises the following steps:
s1, preparing quaternary heteropoly acid anion solution comprising [ PVMoW10O40]4-Solutions or [ PV2MoW9O40]5-A solution;
s2, after the quaternary heteropoly acid anion solution prepared in the step S1 is condensed and refluxed for 2-3h at the temperature of 75-90 ℃, the obtained solution is added into a separating funnel, equal volume of ethyl ether is added for extraction, and the solution is added dropwise into a reaction kettle with the volume ratio of 1:1, oscillating and standing, and collecting the lowest oily substance to obtain a heteropoly acid ether compound;
and S3, placing the heteropoly acid ether compound obtained in the step S2 in an evaporation vessel for ventilation or vacuum drying to remove ether, and obtaining a Keggin type vanadium substituted quaternary heteropoly acid electrocatalysis carbon dioxide material or a Keggin type vanadium substituted quaternary heteropoly acid electrocatalysis carbon dioxide material pre-product.
And further, adding distilled water into the Keggin type vanadium-substituted quaternary heteropoly acid electrocatalysis carbon dioxide material pre-product obtained in the step S3 for recrystallization, and drying in a drying oven after the distilled water is volatilized to dry to obtain the Keggin type vanadium-substituted quaternary heteropoly acid electrocatalysis carbon dioxide material.
Further, the [ PVMoW ] in step S110O40]4-The preparation method of the solution comprises the following steps:
s1.1, preparing NaVO with 0.1-0.3mol/L3·2H2O solution, 1.0-3.0mol/L of Na2WO4·2H2O solution, 0.1-1.2mol/L NaH2PO4·2H2O solution for later use;
s1.2, preparing a mixture with the volume ratio of 1:1, sulfuric acid solution for standby;
s1.3, sequentially stirring NaH according to the volume ratio of 15-402PO4·2H2O solution andNa2WO4·2H2o solution is added to NaVO3·2H2Dropwise adding the concentrated sulfuric acid solution prepared in the step S1.2 into the O solution, and adjusting the pH of the solution to 2.0-2.8 to obtain an orange solution for later use;
s1.4, adding 0.1-2.0mol/L of Na into the orange solution in the step S1.3 under the condition of stirring2MoO4·2H2O solution, orange solution and Na2MoO4·2H2The volume ratio of the O solution is 10-30, and is 0.5-2.25, then the sulfuric acid solution prepared in the step S1.2 is dropwise added, the pH of the solution is adjusted to be 2.0-2.8, and [ PVMoW ] is obtained10O40]4-And (3) solution.
Further, in step S2, [ PVMoW ]10O40]4-The quaternary heteropoly acid anion solution is condensed and refluxed for 3 hours at the temperature of 60-75 ℃.
Further, the Keggin type vanadium substituted quaternary heteropoly acid electrocatalytic carbon dioxide material pre-product obtained in the step S3 is added with distilled water for three-time recrystallization, and the target product H is obtained after the distilled water is volatilized and dried at 60 ℃ for 4 hours4PVMoW10O40·15H2O。
Further, step 1 said [ PV2MoW9O40]5-The preparation method of the solution comprises the following steps: (molarity, please revise by oneself)
S1.1, preparing Na with 1.0-3.5mol/L2WO4·2H2O solution, 0.2-2.0mol/L NaVO3·2H2O solution, 0.10-1.0mol/L Na2MoO4·2H2O solution, weighing 14.0-16.0mol/L (85 wt%) concentrated phosphoric acid solution;
s1.2, preparing a mixture with the volume ratio of 1:1, acetic acid solution and sulfuric acid solution for standby;
s1.3, stirring Na according to the volume ratio of 10-302WO4·2H2Stirring the O solution and the concentrated phosphoric acid solution uniformly, adding the acetic acid solution prepared in the step S1.2, adjusting the pH of the solution to 7.0-8.0, stirring for 1-2h, performing suction filtration and drying on the obtained precipitate to obtain a PW9 precursor, and waiting for the PW9 precursor to be stirredUsing;
s1.4, weighing 2.56g PW9 precursor, dissolving in 30mL deionized water, and dropwise adding NaVO under the condition of stirring3·2H2O solution, na2MoO4·2H2O solution, PW9 precursor solution and NaVO3·2H2O solution, na2MoO4·2H2The volume ratio of O is 15-35, 2-4:1-4, and then the pH of the solution is adjusted to 2.0-2.8 by using the dilute sulfuric acid solution prepared in the step S1.2, so as to obtain [ PV2MoW9O40]5-And (3) solution.
Further, in step S2, [ PV [ -PV ] - ]2MoW9O40]5-The quaternary heteropoly acid anion solution is condensed and refluxed for 2h at 90 ℃.
And further, drying the carbon dioxide material in vacuum for 4 hours at the temperature of 40-60 ℃ in the step S3 to obtain the Keggin type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide material.
The application of a Keggin type vanadium substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material is to dissolve the prepared electrocatalytic carbon dioxide reduction material in Na with a certain concentration2SO4Obtaining CO in aqueous solution2Reduced electrolyte, electrocatalytic reduction of CO2The reaction comprises the following steps:
preparing an electrolyte: dissolving a Keggin type vanadium substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material in Na2SO4An aqueous system forming a catholyte, an electrocatalytic carbon dioxide reducing material in the catholyte at a concentration of 2mM2SO4The volume of the aqueous solution is 30mL, the concentration is 0.1M, and the prepared 30mL of 0.1M dilute sulfuric acid solution is used as the anolyte;
in Na2SO4Electrocatalytic reduction of CO in aqueous systems2：CO2The electrolysis reaction adopts an H-shaped double-chamber electrolytic cell, a Nafion117 cation exchange membrane is adopted between the cathode and the anode of the electrolytic cell, an indium sheet is treated to be used as a working electrode, a Pt electrode is used as an auxiliary electrode, the reference electrode is an Ag/AgCl electrode, 30mL of catholyte containing 2mM polyacid and anolyte containing 0.1M sulfuric acid are respectively addedIntroducing into cathode chamber and anode chamber, inserting vent pipe into the cathode chamber before electrolysis, and introducing N2Exhausting air and continuously introducing CO2Allowing the electrolyte to reach CO within 30min2And (4) saturation.
The invention has the beneficial effects that:
according to the preparation method of the Keggin type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material, the acidity of the prepared heteropoly acid is accurately controlled in a step-by-step acidification mode; compared with other high-temperature high-pressure or electrochemical methods for preparing heteropoly acid, the method has the advantages of simple steps, easy control of reaction, no need of high energy consumption of used equipment, good economy and high yield.
According to the preparation method of the Keggin type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material, the prepared Keggin type structure phosphorus system vanadium-substituted quaternary solid heteropoly acid has high solubility only in an aqueous solution system, the problem that the conventional polyoxometallate and heteropoly acid compound can be dissolved in an organic solution system is solved, and the toxicity of an organic solvent and the pollution to a carbon source in a product are eliminated.
The preparation method of the Keggin type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material comprises the step of preparing a Keggin type structure phosphorus vanadium-substituted quaternary solid heteropoly acid H4PVMoW10O40·15H2O and H5PV2MoW9O40·10H2O shows higher oxidation-reduction property in electrocatalytic reaction, and the CO of a quaternary heteropoly acid system2Shows up to 8.5mA/cm in reduction2The current density of (2).
The preparation method of the Keggin type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material solves the problem that the existing research on heteropoly acid (salt) is only limited to binary or ternary heteropoly acid, and researches the catalytic action of Keggin type phosphorus vanadium-substituted quaternary heteropoly acid in electrochemical reduction.
The preparation of the Keggin type vanadium substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction materialMethod of providing H4PVMoW10O40·15H2O and H5PV2MoW9O40·10H2O two quaternary heteropoly acid electrolytes are proved to be capable of being used for electrochemical reduction reaction to realize electrocatalysis of CO2Production of ethanol and acetic acid C2+Liquid phase product. The faradaic efficiency of the reduction product ethanol is 20-85.06%, the faradaic efficiency of acetic acid is 26-75%, the highest faradaic efficiency is higher than 16% of the previous relevant research on reduction product ethanol of heteropoly acid ionic liquid and 67% of acetic acid, and the Gao Fala efficiency under relatively high current density is realized; and proves that the keggin type quaternary heteropoly acid system is used for CO in the electrolyte2The trapping capacity is higher than that of a heteropoly acid ionic liquid-indium double-catalysis system.
Compared with the industrialized production mode, the preparation method of the Keggin type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material applies the prepared quaternary phosphovanadium molybdenum tungstic heteropoly acid to CO2Reduction production, in addition to obtaining gas phase product CO, also producing C ≥ C2The liquid phase product of (1). In non-organic electrolyte solution, indium sheet is used as working electrode to CO2Electrocatalytic reduction to CO and high value-added C2+Liquid phase product, and acetic acid and ethanol C produced by electrochemical reduction method2+The product does not need higher reaction temperature and pressure, so that the energy consumption in the production process is reduced; and the production steps are simple, the operation is simple, and no toxicity or pollution is caused.
Drawings
FIG. 1 is an XRD diagram of a Keggin type vanadium substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material prepared by the method according to the embodiment;
FIG. 2 is a cyclic voltammetry curve of a Keggin-type vanadium-substituted quaternary heteropolyacid electrocatalytic carbon dioxide reduction material in an aqueous solution system, which is prepared by the method of the first embodiment;
FIG. 3 shows that a Keggin-type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material prepared by the method of the embodiment is respectively used in a three-electrode systemIntroduction of N2And CO2Cyclic voltammogram;
FIG. 4 shows a Keggin-type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material prepared by the method of the embodiment, in an H-type double-chamber electrochemical electrolytic cell, an indium sheet is used as a working electrode, and CO is electrocatalytic reduced in an aqueous solution electrolyte system2I-t curve during reaction;
FIG. 5 shows that the Keggin-type vanadium-substituted quaternary heteropoly acid electro-catalytic carbon dioxide reduction material prepared by the method of the embodiment can be used for electro-reducing CO at a constant potential2A plot of the current density achieved;
FIG. 6 is a gas chromatogram of a gas product detected by gas chromatography after reaction of a Keggin-type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material prepared by the method of the embodiment;
FIG. 7 is a nuclear magnetic hydrogen spectrum of a liquid phase product detected after a Keggin type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material prepared by a method according to an embodiment;
fig. 8 is an XRD pattern of a Keggin-type vanadium-substituted quaternary heteropolyacid electrocatalytic carbon dioxide reduction material prepared by the method of the second embodiment;
fig. 9 is a cyclic voltammogram of a Keggin-type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material prepared by the method of the second embodiment in an aqueous solution system;
FIG. 10 shows that N is introduced into a three-electrode system through a Keggin-type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material prepared by a second specific embodiment method2And CO2Cyclic voltammogram;
FIG. 11 shows a Keggin-type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material prepared by the second specific embodiment, in an H-type double-chamber electrochemical electrolytic cell, an indium sheet is used as a working electrode, and CO is electrocatalytic reduced in an aqueous electrolyte system2I-t curve during reaction;
fig. 12 is a gas chromatogram of a gas product detected by gas chromatography after reaction of a Keggin-type vanadium-substituted quaternary heteropolyacid electrocatalytic carbon dioxide reduction material prepared by the second method in the second embodiment;
fig. 13 is a nuclear magnetic hydrogen spectrum diagram of liquid-phase product detection after a Keggin-type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material prepared by the second specific embodiment method reacts.
Detailed Description
The first embodiment is as follows:
a preparation method of a Keggin type vanadium substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material comprises the following steps:
1) Preparation of heteropolyacid anion [ PVMoW10O40]4-：
1.1 1.22g of NaVO3·2H2Dissolving O in 60mL of deionized water to be used as a vanadium preparation solution; 1.6g NaH2PO4·2H2Dissolving O in 25mL of deionized water to serve as a phosphorus preparation solution; 32.9g of Na2WO4·2H2Dissolving O in 95mL of deionized water to serve as a tungsten preparation solution, and adding the phosphorus preparation solution and the tungsten preparation solution into the vanadium preparation solution in sequence under the stirring action to change the solution into orange yellow.
1.2 Prepared volume ratio of 1:1 in 500mL of sulfuric acid solution for use.
1.3 ) to the orange-yellow solution 1.2) H was added dropwise4PVMoW10O40The pH of the prepared sulfuric acid solution is adjusted to 2.0-2.8, and the solution turns orange.
1.4 2.4g of Na2MoO4·2H2O is dissolved in 10mL of deionized water and added to the orange solution, at which point a further drop of 1:1, and adjusting the pH of the solution to 2.0-2.8.
1.5 The pH adjusted solution was refluxed at 60-75 ℃ for 3h and cooled to room temperature to give an orange solution.
2) Extracting heteropoly acid anions to obtain heteropoly acid solids:
2.1 Extraction: transferring the orange solution into a separating funnel, adding equal volume of diethyl ether for repeated extraction, and dropwise adding a solvent with the volume ratio of 1:1, shaking and standing to separate into three layers, wherein the orange red oily matter at the lowest layer is heteropoly acid etherate.
2.2 Recrystallization: taking the lower layer oily heteropoly acid compound, putting the lower layer oily heteropoly acid compound in an evaporating dish, ventilating or drying in vacuum to remove ether completely, and obtaining powdery heteropoly acid crystals; adding distilled water for three-time recrystallization, and drying at 60 ℃ for 4H after the distilled water is volatilized to be dry to obtain a target product H4PVMoW10O40·15H2O。
An XRD pattern of the Keggin-type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material described in the present embodiment is shown in fig. 1, and it can be seen from the XRD pattern that the prepared kggggin-type quaternary heteropoly acid has a certain crystal structure, and diffraction peaks mainly concentrate in four regions, 2 θ of 7-10 °, 16-22 °, 25-30 ° and 33-38 °, belonging to characteristic diffraction peaks of Keggin-structured heteropoly acids.
In the Keggin type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material of the embodiment, 0.176g of quaternary heteropoly acid H4PVMoW10O40·15H2O dissolved in 30mL of 0.1MNa2SO4An aqueous solution system, wherein the electrolyte of the aqueous solution system is catholyte, the concentration of the heteropoly acid in the solution is 2mM2SO4The volume of the aqueous solution was 30mL. 493.7mL of deionized water and 2.715mL of concentrated sulfuric acid are taken and stirred and mixed to obtain 0.1M of dilute sulfuric acid solution, namely anolyte, and the volume of the used anolyte is 30mL.
CO2The electrolysis reaction adopts an H-shaped double-chamber electrolytic cell, a Nafion117 cation exchange membrane is used between the cathode and the anode of the electrolytic cell, only protons are allowed to pass through the cation exchange membrane, a proton source is provided for the reaction of the cathode region, and the oxygen generated in the anode region in the reaction process is ensured not to influence the cathode region. The cathode was added with 30mL of 0.1M H4PVMoW10O40·15H2Na of O2SO4An aqueous solution of a carboxylic acid and a carboxylic acid,
the anode was 30mL of 0.1M dilute sulfuric acid solution. The indium sheet is treated to be used as a working electrode, the Pt electrode is used as an auxiliary electrode, and the reference electrode is an Ag/AgCl electrode. Before electrolysis, a vent pipe is inserted into the cathode chamber, and a certain amount of N is introduced into the cathode chamber2Exhausting air, and continuously introducing C at flow rate of 10mL/minO2The electrolyte is saturated within 30min, and the current is effectively prevented from rapidly fluctuating due to bubbles generated by gas introduction in the electrolysis process. Then electrolyzing CO at constant potential under the voltage of-0.7-1.4V2Collecting catholyte after the reaction is finished, testing the catholyte by gas chromatography and nuclear magnetic hydrogen spectrum,
fig. 2 is a cyclic voltammetry curve of the Keggin type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material in an aqueous solution system, and it can be known from fig. 2 that the prepared quaternary heteropoly acid can be dissolved and ionized in the aqueous solution system, shows characteristic redox peaks of different hetero-polyatomic atoms, and maintains good electrochemical activity.
FIG. 3 shows that N is respectively introduced into a three-electrode system by the Keggin type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material2And CO2Cyclic voltammetry was performed by adding 30mL of 0.1M Na to the prepared heteropoly acid2SO4The concentrations of the heteropoly acid in the water solution are all 2mM as the cathode electrolyte; the anolyte is 30mL of dilute sulfuric acid solution with the concentration of 0.1M; assembling the product into an H-shaped double-chamber electrolytic cell, adopting a three-electrode system, wherein an indium sheet is a working electrode, a Pt electrode is an auxiliary electrode, an Ag/AgCl electrode is a reference electrode, and test heteropoly acids are respectively in an N state2And CO2Cyclic voltammogram under ambient. As shown in FIG. 3, N is introduced2Post-and CO-introduction2Cyclic voltammograms after saturation is reached; from FIG. 3, it can be seen that CO is introduced under the action of the working electrode2The change of the oxidation-reduction potential peaks of the heteropoly acid before and after the reaction can prove that CO is generated2It was confirmed that reduction reaction occurred in the indium electrode and the electrolyte.
FIG. 4 shows that the Keggin type vanadium substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material is used for electrocatalytic reduction of CO in an aqueous solution electrolyte system in an H-type double-chamber electrochemical electrolytic cell by taking an indium sheet as a working electrode2I-t curve during reaction; preparing prepared heteropoly acid into catholyte in an H-shaped double-chamber electrolytic cell by adopting a three-electrode system, applying a constant voltage of-0.9V to the electrolyte system, and performing constant potential electrolysis to obtain I-t curveA wire. FIG. 4 shows CO at constant potential2Current versus time during electrocatalytic reduction.
FIG. 5 shows that the Keggin type vanadium-substituted quaternary heteropoly acid electro-catalytic carbon dioxide reduction material can be used for electrically reducing CO at constant potential2The obtained current density graph is that the prepared quaternary heteropoly acid is configured into electrolyte, and electrolysis is carried out under constant-1.3V and-1.4V voltage, and the current density curve is shown in figure 5.
FIG. 6 is a gas chromatogram of a gas product detected by gas chromatography after reaction of the Keggin type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material; collecting the gas generated during constant potential electrolysis with gas collecting bag, detecting in gas chromatography, and obtaining chromatogram as shown in FIG. 6, H4PVMoW10O40·15H2The Faraday efficiency of the O heteropoly acid system product CO is 3% -23.04%.
FIG. 7 is a nuclear magnetic hydrogen spectrum diagram of a liquid-phase product detected after a Keggin type vanadium-substituted quaternary heteropoly acid electrocatalysis carbon dioxide reduction material reacts; and (3) performing constant potential electrolysis on the prepared heteropoly acid, collecting the catholyte after reaction, detecting a liquid-phase nuclear magnetic hydrogen spectrum, and quantitatively analyzing a nuclear magnetic result to obtain the product acetic acid with the Faraday efficiency of 75% and ethanol with the Faraday efficiency of 34.6% at most. FIG. 7 is H4PVMoW10O40·15H2A nuclear magnetic hydrogen spectrum product diagram after the electrolysis of the O heteropoly acid system. Therefore, the quaternary heteropoly acid with the Keggin structure is shown to react with CO2Reduction to C2+The liquid phase product has high-efficiency catalytic action, so the keggin type vanadium substituted quaternary heteropoly acid can be applied to CO in industry2Preparation of C by electrochemical reduction2+A chemical.
The second embodiment is as follows:
a preparation method of a Keggin type vanadium substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material comprises the following steps:
1) Preparation of heteropolyacid anion [ PV2MoW9O40]5-：
1.1 12g of NaWO)4·2H2Dissolving O in 15mL deionized water, stirring, and adding 0.4mL of 14.0-16.0mol/L (85 wt%) concentrated H3PO4The pH of the solution was adjusted to 7.0-8.0.
1.2 Adjusting the pH of the solution to 7.0-8.0 with glacial acetic acid, stirring for 1-2h to generate a large amount of white precipitate, filtering, and drying to obtain a precursor PW 9.
1.3 0.316g NaVO3·2H2O and 0.242g Na2MoO4·2H2O was dissolved in 4mL and 3mL of deionized water, respectively, and added dropwise to a solution prepared by dissolving 2.56g of PW9 in 30mL of deionized water.
1.4 Adjusting the pH of the solution to 2.0-2.8 with dilute sulfuric acid, and condensing and refluxing at 90 ℃ for 2h to obtain heteropoly acid anions.
2) Extracting heteropoly acid anions to obtain heteropoly acid solids:
2.1 Extraction: transferring the solution into a separating funnel, adding equal volume of diethyl ether for repeated extraction, and dropwise adding a solvent with a volume ratio of 1:1, shaking and standing to separate three layers, wherein the lowest red oily substance is heteropoly acid etherate.
2.2 Vacuum drying: taking the lower oily heteropolyether compound, drying in vacuum to remove ether, volatilizing to obtain orange solid powder, namely the target product H5PV2MoW9O40·10H2O。
In the Keggin type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material of the embodiment, an XRD diagram is shown in fig. 8, and it can be seen from the XRD diagram that the prepared kggggin type quaternary heteropoly acid has a certain crystal structure, and diffraction peaks mainly concentrate in four regions of 2 θ of 7-10 °, 16-22 °, 25-30 ° and 33-38 °, and belong to characteristic diffraction peaks of the Keggin structure heteropoly acid.
In the Keggin type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material of the embodiment, 0.220gH is prepared5PV2MoW9O40·10H2O dissolved in 30mL of 0.1MNa2SO4An aqueous solution system, wherein the electrolyte of the aqueous solution system is catholyte, the concentration of the heteropoly acid in the solution is 2mM2SO4The volume of the aqueous solution was 30mL. 493.7mL of deionized water and 2.715mL of concentrated sulfuric acid are taken and stirred and mixed to obtain 0.1M dilute sulfuric acid solution, namely anolyte, wherein the volume of the anolyte is 30mL.
CO2The electrolysis reaction adopts an H-shaped double-chamber electrolytic cell, a Nafion117 cation exchange membrane is used between the cathode and the anode of the electrolytic cell, only protons are allowed to pass through the cation exchange membrane, a proton source is provided for the reaction of the cathode region, and the oxygen generated in the anode region in the reaction process is ensured not to influence the cathode region. The cathode was added with 30mL of 0.1M H5PV2MoW9O40·10H2Na of O2SO4The aqueous solution, anode, was 30mL of 0.1M dilute sulfuric acid solution. The indium sheet is treated to be used as a working electrode, the Pt electrode is used as an auxiliary electrode, and the reference electrode is an Ag/AgCl electrode. Before electrolysis, a vent pipe is inserted into the cathode chamber, and a certain amount of N is introduced into the cathode chamber2Exhausting air, and continuously introducing CO at a flow rate of 10mL/min2The 30min leads the electrolyte to reach saturation, and effectively prevents the current from rapidly fluctuating caused by bubbles generated by gas introduction in the electrolytic process. Then electrolyzing CO at constant potential under the voltage of-0.8 to-1.5V2Collecting catholyte after the reaction is finished, testing the catholyte by gas chromatography and nuclear magnetic hydrogen spectrum,
fig. 9 is a cyclic voltammetry curve of the Keggin-type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material in an aqueous solution system, and it can be known from fig. 9 that the prepared quaternary heteropoly acid can be dissolved and ionized in the aqueous solution system, shows characteristic redox peaks of different hetero-polyatomic atoms, and maintains good electrochemical activity.
FIG. 10 shows that N is respectively introduced into a three-electrode system by the Keggin type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material2And CO2Cyclic voltammetry of the sample was determined by adding 30mL of 0.1M Na to the prepared heteropoly acid2SO4The concentrations of the heteropoly acids in the water solution are all 2mM as cathode electrolyte; the anolyte is 30mL of dilute sulfuric acid solution with the concentration of 0.1M; assembling the electrolytic cell into an H-shaped double-chamber electrolytic cell by adopting a three-electrode system, wherein indium sheets are working electrodesThe electrode, pt electrode as auxiliary electrode, ag/AgCl electrode as reference electrode, and test heteropoly acid in N2And CO2Cyclic voltammogram under ambient. As shown in FIG. 10, N is introduced2Post-and CO-introduction2Cyclic voltammograms after saturation is reached; it can be seen from FIG. 10 that CO is introduced by the working electrode2The change of the oxidation-reduction potential peaks of the heteropoly acid before and after the reaction can prove that CO is generated2It was confirmed that a reduction reaction occurred in the indium electrode and the electrolyte.
FIG. 11 shows that the Keggin type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material is used for electrocatalytic reduction of CO in an aqueous solution electrolyte system in an H-shaped double-chamber electrochemical electrolytic cell by taking an indium sheet as a working electrode2I-t curve during reaction; preparing prepared heteropoly acid into catholyte in an H-shaped double-chamber electrolytic cell by adopting a three-electrode system, applying a constant voltage of-0.9V to the electrolyte system, and carrying out constant potential electrolysis to obtain an I-t curve. FIG. 11 shows CO at constant potential2Current versus time during electrocatalytic reduction.
FIG. 12 is a gas chromatogram of a gas product detected by gas chromatography after reaction of the Keggin-type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material; collecting the generated gas with gas collecting bag during constant potential electrolysis, detecting in gas chromatography with chromatogram shown in FIG. 12, and measuring the content of hydrogen5PV2MoW9O40·10H2The Faraday efficiency of the O heteropoly acid system product CO is 2.6-38%.
FIG. 13 is a nuclear magnetic hydrogen spectrum diagram of liquid phase product detection after reaction of the Keggin type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material; and (3) performing constant potential electrolysis on the prepared heteropoly acid, collecting the catholyte after reaction, detecting a liquid-phase nuclear magnetic hydrogen spectrum, and quantitatively analyzing a nuclear magnetic result to obtain a product ethanol with the Faraday efficiency of 85.06 at the highest. FIG. 13 is H5PV2MoW9O40·10H2And (3) a nuclear magnetic hydrogen spectrum product diagram of the electrolyzed O heteropoly acid system. Therefore, the quaternary heteropoly acid with the Keggin structure is shown to react with CO2Reduction to C2+The liquid phase product has high-efficiency catalytic action, so the keggin type vanadium-substituted quaternary heteropoly acid can be applied to CO in industry2Electrochemical reduction for preparing C2+A chemical.
The third concrete implementation mode:
a preparation method of a Keggin type vanadium substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material comprises the following steps:
s1, preparing quaternary heteropoly acid anion solution comprising [ PVMoW10O40]4-Solutions or [ PV2MoW9O40]5-A solution;
s2, after the quaternary heteropoly acid anion solution prepared in the step S1 is condensed and refluxed for 2-3h at the temperature of 75-90 ℃, the obtained solution is added into a separating funnel, equal volume of ethyl ether is added for extraction, and the solution is added dropwise into a reaction kettle with the volume ratio of 1:1, oscillating and standing, and collecting the lowest oily substance to obtain a heteropoly acid ether compound;
and S3, placing the heteropoly acid ether complex obtained in the step S2 in an evaporation vessel for ventilation or vacuum drying to remove all ether in the heteropoly acid ether complex, and obtaining a Keggin type vanadium substituted quaternary heteropoly acid electrocatalysis carbon dioxide material or a Keggin type vanadium substituted quaternary heteropoly acid electrocatalysis carbon dioxide material pre-product.
The fourth concrete implementation mode:
according to the third specific embodiment, the preparation method of the Keggin type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material comprises the steps of adding distilled water into an electrocatalytic carbon dioxide reduction material pre-product obtained in the step S3 for recrystallization, and drying in a drying oven after the distilled water is volatilized to dryness to obtain the Keggin type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide material.
The fifth concrete implementation mode is as follows:
according to the third specific embodiment, the [ PVMoW ] in step S1 is the preparation method of the Keggin-type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material10O40]4-The preparation method of the solution comprises the following steps:
s1.1, preparing NaVO with 0.1-0.3mol/L3·2H2O solution, 1.0-3.0mol/L of Na2WO4·2H2O solution, 0.1-1.2mol/L NaH2PO4·2H2O solution for later use;
s1.2, preparing a mixture with the volume ratio of 1:1, sulfuric acid solution for standby;
s1.3, sequentially mixing NaH with the stirring according to the volume ratio of 15-402PO4·2H2O solution and Na2WO4·2H2O solution is added to NaVO3·2H2Dropwise adding the sulfuric acid solution prepared in the step S1.2 into the O solution, and adjusting the pH of the solution to 2.0-2.8 to obtain an orange solution for later use;
s1.4, adding 0.1-2.0mol/L of Na into the orange solution in the step S1.3 under the condition of stirring2MoO4·2H2O solution, orange solution and Na2MoO4·2H2The volume ratio of the O solution is 10-30, and is 0.5-2.25, then the concentrated sulfuric acid solution prepared in the step S1.2 is dropwise added, the pH of the solution is adjusted to be 2.0-2.8, and [ PVMoW ] is obtained10O40]4-And (3) solution.
The sixth specific implementation mode:
according to the third specific embodiment, in the step S2, the [ PVMoW ] is used as the material for preparing the Keggin-type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material10O40]]4-The quaternary heteropoly acid anion solution is condensed and refluxed for 3 hours at the temperature of 60-75 ℃.
The seventh embodiment:
according to the third specific embodiment, the Keggin type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material preparation method comprises the steps of obtaining a Keggin type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide material pre-product in the step S3, adding distilled water for carrying out tertiary recrystallization, drying at 60 ℃ for 4 hours after the distilled water is volatilized to be dried, and obtaining a target product H4PVMoW10O40·15H2O。
The specific implementation mode eight:
according to the third embodimentA preparation method of a Keggin type vanadium substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material, wherein [ PV ] is described in step 12MoW9O40]5-The preparation method of the solution comprises the following steps:
s1.1, preparing Na with 1.0-3.5mol/L2WO4·2H2NaVO with O solution 0.2-2.0mol/L3·2H2O solution, 0.10-1.0mol/L Na2MoO4·2H2O solution, weighing 14.0-16.0mol/L (85 wt%) concentrated phosphoric acid solution;
s1.2, preparing a mixture with a volume ratio of 1:1, acetic acid solution and sulfuric acid solution for standby;
s1.3, stirring Na according to the volume ratio of 10-302WO4·2H2Uniformly stirring the O solution and the concentrated phosphoric acid solution, adding the acetic acid solution prepared in the step S1.2, adjusting the pH of the solution to 7.0-8.0, stirring for 1-2h, performing suction filtration on the obtained precipitate, and drying to obtain a PW9 precursor for later use;
s1.4, weighing 2.56g PW9 precursor, dissolving in 30mL deionized water, and dripping NaVO under the condition of stirring3·2H2O solution, na2MoO4·2H2O solution, PW9 precursor solution and NaVO3·2H2O solution, na2MoO4·2H2The volume ratio of O is 15-35, 2-4:1-4, and then the pH of the solution is adjusted to 2.0-2.8 by the dilute sulfuric acid solution prepared in the step S1.2, so as to obtain [ PV2MoW9O40]5-And (3) solution.
The specific implementation method nine:
according to the third embodiment, in the step S2 of the preparation method of the electrocatalytic carbon dioxide reduction material, [ PV ]2MoW9O40]5-The quaternary heteropoly acid anion solution is condensed and refluxed for 2h at 90 ℃.
The detailed implementation mode is ten:
according to the third specific embodiment, in the step S3, vacuum drying is carried out for 4 hours at 40-60 ℃ to obtain the Keggin type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide material.
The concrete implementation mode eleven:
according to the third specific embodiment, the Keggin vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material is prepared by the preparation method of the Keggin vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material.
The specific implementation mode twelve:
according to the application of the Keggin vanadium-substituted quaternary heteropolyacid electrocatalytic carbon dioxide reduction material prepared by the preparation method of the Keggin vanadium-substituted quaternary heteropolyacid electrocatalytic carbon dioxide reduction material, the prepared Keggin vanadium-substituted quaternary heteropolyacid electrocatalytic carbon dioxide reduction material is dissolved in Na with a certain concentration2SO4Obtaining CO in aqueous solution2Reduced electrolyte, electrocatalytic reduction of CO2The reaction comprises the following steps:
preparing an electrolyte: dissolving a Keggin type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material in Na2SO4An aqueous solution system which forms a cathode electrolyte, the concentration of a Keggin type vanadium substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material in the cathode electrolyte is 2mM2SO4The volume of the aqueous solution is 30mL, the concentration is 0.1M, and 30mL of prepared 0.1M dilute sulfuric acid solution is used as anolyte;
in Na2SO4Electrocatalytic reduction of CO in aqueous systems2：CO2The electrolysis reaction adopts an H-shaped double-chamber electrolytic cell, a Nafion117 cation exchange membrane is adopted between the cathode and the anode of the electrolytic cell, an indium sheet is treated to be used as a working electrode, a Pt electrode is used as an auxiliary electrode, the reference electrode is an Ag/AgCl electrode, 30mL of catholyte containing 2mM polyacid and anolyte containing 0.1M sulfuric acid are respectively added into a cathode chamber and an anode chamber, a vent pipe is inserted into the cathode chamber before electrolysis, and a certain amount of N is firstly introduced2Exhausting air and continuously introducing CO2Allowing the electrolyte to reach CO within 30min2And (4) saturation.
Claims (10)
1. A preparation method of a Keggin type vanadium substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material is characterized by comprising the following steps: the method comprises the following steps:
s1, preparing a quaternary heteropoly acid anion solution comprising [ PVMoW ]10O40]4-Solutions or [ PV2MoW9O40]5-A solution;
s2, after the quaternary heteropoly acid anion solution prepared in the step S1 is condensed and refluxed for 2-3h at the temperature of 75-90 ℃, the obtained solution is transferred into a separating funnel, equal volume of ethyl ether is added for extraction, and the ethyl ether with the volume ratio of 1:1, oscillating and standing, and collecting the lowest oily substance to obtain a heteropoly acid ether compound;
and S3, placing the heteropoly acid ether compound obtained in the step S2 in an evaporation vessel for ventilation or vacuum drying to remove ether, and obtaining a Keggin type vanadium substituted quaternary heteropoly acid electrocatalysis carbon dioxide material or a Keggin type vanadium substituted quaternary heteropoly acid electrocatalysis carbon dioxide material pre-product.
2. The preparation method of the Keggin type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material according to claim 1, which is characterized by comprising the following steps: and (4) adding distilled water into the Keggin type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide material pre-product obtained in the step (S3) for recrystallization, and drying in an oven after the distilled water is volatilized to be dry to obtain the Keggin type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide material.
3. The preparation method of the Keggin type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material according to claim 2, which is characterized by comprising the following steps: [ PVMoW ] described in step S110O40]4-The preparation method of the solution comprises the following steps:
s1.1, naVO with 0.1-0.3mol/L configuration3·2H2O solution, 1.0-3.0mol/L of Na2WO4·2H2O solution, 0.1-1.2mol/L NaH2PO4·2H2O solution for later use;
s1.2, preparing a mixture with the volume ratio of 1:1, sulfuric acid solution for standby;
s1.3, sequentially mixing NaH with the stirring according to the volume ratio of 15-402PO4·2H2O solution and Na2WO4·2H2O solution is added to NaVO3·2H2Dropwise adding the sulfuric acid solution prepared in the step S1.2 into the O solution, and adjusting the pH of the solution to 2.0-2.8 to obtain an orange solution for later use;
s1.4, adding 0.1-2.0mol/L of Na into the orange solution in the step S1.3 under the condition of stirring2MoO4·2H2O solution, orange solution and Na2MoO4·2H2The volume ratio of the O solution is 10-3010O40]4-And (3) solution.
4. The preparation method of the Keggin type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material according to claim 3, wherein the preparation method comprises the following steps: in step S2, [ PVMoW ]10O40]4-The quaternary heteropoly acid anion solution is condensed and refluxed for 3 hours at the temperature of 60-75 ℃.
5. The preparation method of the Keggin type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material according to claim 4, which is characterized by comprising the following steps: the pre-product of the Keggin type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide material obtained in the step S3 is added with distilled water for three-time recrystallization, and the target product H is obtained after the distilled water is volatilized and dried at 60 ℃ for 4 hours4PVMoW10O40·15H2O。
6. The preparation method of the Keggin type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material according to claim 2, which is characterized by comprising the following steps: [ PV ] described in step 12MoW9O40]5-The preparation method of the solution comprises the following steps:
s1.1, preparing Na with 1.0-3.5mol/L2WO4·2H2O solution, 0.2-2.0mol/L NaVO3·2H2O solution, 0.10-1.0mol/L Na2MoO4·2H2O solution, weighing 14.0-16.0mol/L concentrated phosphoric acid solution;
s1.2, preparing a mixture with the volume ratio of 1:1, acetic acid solution and sulfuric acid solution for standby;
s1.3, stirring Na according to the volume ratio of 10-302WO4·2H2Uniformly stirring the O solution and the concentrated phosphoric acid solution, adding the acetic acid solution prepared in the step S1.2, adjusting the pH of the solution to 7.0-8.0, stirring for 1-2h, performing suction filtration on the obtained precipitate, and drying to obtain a PW9 precursor for later use;
s1.4, weighing 2.56g PW9 precursor, dissolving in 30mL deionized water, and dropwise adding NaVO under the condition of stirring3·2H2O solution, na2MoO4·2H2O solution, PW9 precursor solution and NaVO3·2H2O solution, na2MoO4·2H2The volume ratio of O is 15-35, 2-4:1-4, and then the pH of the solution is adjusted to 2.0-2.8 by the dilute sulfuric acid solution prepared in the step S1.2, so as to obtain [ PV2MoW9O40]5-And (3) solution.
7. The preparation method of the Keggin type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material according to claim 6, which is characterized by comprising the following steps: in step S2, [ PV [ -PV ]2MoW9O40]5-The quaternary heteropoly acid anion solution is condensed and refluxed for 2h at 90 ℃.
8. The preparation method of the Keggin type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material according to claim 7, which is characterized by comprising the following steps: and (S3) vacuum drying for 4h at 40-60 ℃ to obtain the Keggin type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide material.
9. The Keggin type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material prepared by the preparation method of any one of claims 1-8.
10. The application of the Keggin type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material prepared by the preparation method according to any one of claims 1-8 is characterized in that: dissolving the prepared Keggin type vanadium-substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material in Na with certain concentration2SO4Obtaining CO in aqueous solution2Reduced electrolyte, electrocatalytic reduction of CO2The reaction comprises the following steps:
preparing an electrolyte: dissolving a Keggin type vanadium substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material in Na2SO4An aqueous solution system which forms a cathode electrolyte, the concentration of a Keggin type vanadium substituted quaternary heteropoly acid electrocatalytic carbon dioxide reduction material in the cathode electrolyte is 2mM2SO4The volume of the aqueous solution is 30mL, the concentration is 0.1M, and the prepared 30mL of 0.1M dilute sulfuric acid solution is used as the anolyte;
in Na2SO4Electrocatalytic reduction of CO in aqueous systems2：CO2The electrolysis reaction adopts an H-shaped double-chamber electrolytic cell, a Nafion117 cation exchange membrane is adopted between the cathode and the anode of the electrolytic cell, an indium sheet is treated to be used as a working electrode, a Pt electrode is used as an auxiliary electrode, the reference electrode is an Ag/AgCl electrode, 30mL of catholyte containing 2mM polyacid and anolyte containing 0.1M sulfuric acid are respectively added into a cathode chamber and an anode chamber, a vent pipe is inserted into the cathode chamber before electrolysis, and a certain amount of N is firstly introduced2Exhausting air and continuously introducing CO2Allowing the electrolyte to reach CO within 30min2And (4) saturation.
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN108796548A (en) * | 2018-07-05 | 2018-11-13 | 哈尔滨工业大学 | The method that electro-catalysis reduction carbon dioxide prepares formic acid and acetic acid in heteropolyacid anions-acetonitrile-water ternary electrolyte system |
| US20190030516A1 (en) * | 2017-07-25 | 2019-01-31 | Central China Normal University | Monatomic metal-doped few-layer molybdenum disulfide electrocatalytic material, preparing method thereof, and method for electrocatalytic nitrogen fixation |
| CN112144073A (en) * | 2020-10-10 | 2020-12-29 | 哈尔滨工业大学 | Electrocatalytic reduction of CO under heteropolyacid ionic liquid-indium double-catalytic system2Method for preparing ethanolic acid |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20190030516A1 (en) * | 2017-07-25 | 2019-01-31 | Central China Normal University | Monatomic metal-doped few-layer molybdenum disulfide electrocatalytic material, preparing method thereof, and method for electrocatalytic nitrogen fixation |
| CN108796548A (en) * | 2018-07-05 | 2018-11-13 | 哈尔滨工业大学 | The method that electro-catalysis reduction carbon dioxide prepares formic acid and acetic acid in heteropolyacid anions-acetonitrile-water ternary electrolyte system |
| CN112144073A (en) * | 2020-10-10 | 2020-12-29 | 哈尔滨工业大学 | Electrocatalytic reduction of CO under heteropolyacid ionic liquid-indium double-catalytic system2Method for preparing ethanolic acid |
Non-Patent Citations (1)
| Title |
|---|
| 尹彦冰等: ""Keggin型P-V-Mo-W 四元杂多酸的合成及表征"", 《昆明理工大学学报（自然科学版）》, vol. 39, no. 2, 15 April 2014 (2014-04-15), pages 97 - 100 * |
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