CN115155647B - Preparation method and application of BCN aerogel catalyst loaded with bimetallic single atoms - Google Patents
Preparation method and application of BCN aerogel catalyst loaded with bimetallic single atoms Download PDFInfo
- Publication number
- CN115155647B CN115155647B CN202211022983.XA CN202211022983A CN115155647B CN 115155647 B CN115155647 B CN 115155647B CN 202211022983 A CN202211022983 A CN 202211022983A CN 115155647 B CN115155647 B CN 115155647B
- Authority
- CN
- China
- Prior art keywords
- bcn
- aerogel
- loaded
- noble metal
- catalyst
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 239000004964 aerogel Substances 0.000 title claims abstract description 145
- 239000003054 catalyst Substances 0.000 title claims abstract description 87
- 238000002360 preparation method Methods 0.000 title claims abstract description 34
- 229910000510 noble metal Inorganic materials 0.000 claims abstract description 105
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 claims abstract description 102
- 238000001354 calcination Methods 0.000 claims abstract description 56
- 238000011068 loading method Methods 0.000 claims abstract description 41
- 239000012855 volatile organic compound Substances 0.000 claims abstract description 23
- KRKNYBCHXYNGOX-UHFFFAOYSA-N citric acid Chemical compound OC(=O)CC(O)(C(O)=O)CC(O)=O KRKNYBCHXYNGOX-UHFFFAOYSA-N 0.000 claims description 54
- 239000011265 semifinished product Substances 0.000 claims description 36
- 238000003756 stirring Methods 0.000 claims description 30
- 239000000243 solution Substances 0.000 claims description 29
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 claims description 26
- KGBXLFKZBHKPEV-UHFFFAOYSA-N boric acid Chemical compound OB(O)O KGBXLFKZBHKPEV-UHFFFAOYSA-N 0.000 claims description 24
- 239000004327 boric acid Substances 0.000 claims description 24
- 239000002243 precursor Substances 0.000 claims description 24
- 238000009210 therapy by ultrasound Methods 0.000 claims description 24
- 239000000017 hydrogel Substances 0.000 claims description 21
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 20
- 238000001035 drying Methods 0.000 claims description 19
- 238000001914 filtration Methods 0.000 claims description 19
- 238000005406 washing Methods 0.000 claims description 18
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 claims description 17
- 239000004202 carbamide Substances 0.000 claims description 17
- 229920002472 Starch Polymers 0.000 claims description 16
- 239000008107 starch Substances 0.000 claims description 16
- 235000019698 starch Nutrition 0.000 claims description 16
- 229910052757 nitrogen Inorganic materials 0.000 claims description 13
- 239000011780 sodium chloride Substances 0.000 claims description 13
- 238000000227 grinding Methods 0.000 claims description 10
- 238000010438 heat treatment Methods 0.000 claims description 10
- 239000012266 salt solution Substances 0.000 claims description 6
- 150000003839 salts Chemical class 0.000 claims description 6
- 101710134784 Agnoprotein Proteins 0.000 claims description 3
- 229910021591 Copper(I) chloride Inorganic materials 0.000 claims description 3
- 101150003085 Pdcl gene Proteins 0.000 claims description 3
- OXBLHERUFWYNTN-UHFFFAOYSA-M copper(I) chloride Chemical compound [Cu]Cl OXBLHERUFWYNTN-UHFFFAOYSA-M 0.000 claims description 3
- 230000000593 degrading effect Effects 0.000 claims description 3
- 238000001816 cooling Methods 0.000 claims description 2
- 229910052751 metal Inorganic materials 0.000 abstract description 42
- 239000002184 metal Substances 0.000 abstract description 41
- 230000003197 catalytic effect Effects 0.000 abstract description 29
- 238000000034 method Methods 0.000 abstract description 18
- 230000015556 catabolic process Effects 0.000 abstract description 16
- 238000006731 degradation reaction Methods 0.000 abstract description 16
- 150000002739 metals Chemical class 0.000 abstract description 12
- 230000000694 effects Effects 0.000 abstract description 10
- 238000006555 catalytic reaction Methods 0.000 abstract description 6
- 230000002195 synergetic effect Effects 0.000 abstract description 5
- 230000008859 change Effects 0.000 abstract description 3
- 238000005470 impregnation Methods 0.000 abstract description 3
- 238000012545 processing Methods 0.000 abstract description 2
- 239000007864 aqueous solution Substances 0.000 description 20
- 230000000052 comparative effect Effects 0.000 description 18
- 238000006243 chemical reaction Methods 0.000 description 17
- 230000003647 oxidation Effects 0.000 description 17
- 238000007254 oxidation reaction Methods 0.000 description 17
- 239000002002 slurry Substances 0.000 description 16
- 125000004429 atom Chemical group 0.000 description 15
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 11
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 9
- 239000000463 material Substances 0.000 description 9
- 239000008367 deionised water Substances 0.000 description 8
- 229910021641 deionized water Inorganic materials 0.000 description 8
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 7
- 239000011259 mixed solution Substances 0.000 description 7
- 239000007789 gas Substances 0.000 description 6
- 238000001000 micrograph Methods 0.000 description 6
- KDLHZDBZIXYQEI-UHFFFAOYSA-N palladium Substances [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 6
- 230000009286 beneficial effect Effects 0.000 description 5
- 239000000969 carrier Substances 0.000 description 5
- 229910021645 metal ion Inorganic materials 0.000 description 5
- 230000008569 process Effects 0.000 description 5
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 4
- 239000010931 gold Substances 0.000 description 4
- 230000003993 interaction Effects 0.000 description 4
- 150000002500 ions Chemical class 0.000 description 4
- 239000002957 persistent organic pollutant Substances 0.000 description 4
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 229910052796 boron Inorganic materials 0.000 description 3
- 229910052799 carbon Inorganic materials 0.000 description 3
- 230000006378 damage Effects 0.000 description 3
- 239000001301 oxygen Substances 0.000 description 3
- 229910052760 oxygen Inorganic materials 0.000 description 3
- CTQNGGLPUBDAKN-UHFFFAOYSA-N O-Xylene Chemical group CC1=CC=CC=C1C CTQNGGLPUBDAKN-UHFFFAOYSA-N 0.000 description 2
- ISWSIDIOOBJBQZ-UHFFFAOYSA-N Phenol Chemical compound OC1=CC=CC=C1 ISWSIDIOOBJBQZ-UHFFFAOYSA-N 0.000 description 2
- 150000001555 benzenes Chemical class 0.000 description 2
- 230000005587 bubbling Effects 0.000 description 2
- MVPPADPHJFYWMZ-UHFFFAOYSA-N chlorobenzene Chemical compound ClC1=CC=CC=C1 MVPPADPHJFYWMZ-UHFFFAOYSA-N 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 239000006185 dispersion Substances 0.000 description 2
- 239000003344 environmental pollutant Substances 0.000 description 2
- 238000011156 evaluation Methods 0.000 description 2
- AMWRITDGCCNYAT-UHFFFAOYSA-L hydroxy(oxo)manganese;manganese Chemical compound [Mn].O[Mn]=O.O[Mn]=O AMWRITDGCCNYAT-UHFFFAOYSA-L 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000012621 metal-organic framework Substances 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 239000002105 nanoparticle Substances 0.000 description 2
- 231100000719 pollutant Toxicity 0.000 description 2
- 239000010970 precious metal Substances 0.000 description 2
- 238000000746 purification Methods 0.000 description 2
- 238000011084 recovery Methods 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- WOCIAKWEIIZHES-UHFFFAOYSA-N ruthenium(iv) oxide Chemical group O=[Ru]=O WOCIAKWEIIZHES-UHFFFAOYSA-N 0.000 description 2
- 238000001878 scanning electron micrograph Methods 0.000 description 2
- 239000004408 titanium dioxide Substances 0.000 description 2
- 238000009827 uniform distribution Methods 0.000 description 2
- ISPYQTSUDJAMAB-UHFFFAOYSA-N 2-chlorophenol Chemical compound OC1=CC=CC=C1Cl ISPYQTSUDJAMAB-UHFFFAOYSA-N 0.000 description 1
- 229910002701 Ag-Co Inorganic materials 0.000 description 1
- 229910017937 Ag-Ni Inorganic materials 0.000 description 1
- 229910017984 Ag—Ni Inorganic materials 0.000 description 1
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 1
- 229910017390 Au—Fe Inorganic materials 0.000 description 1
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 1
- 229910020599 Co 3 O 4 Inorganic materials 0.000 description 1
- QPLDLSVMHZLSFG-UHFFFAOYSA-N Copper oxide Chemical compound [Cu]=O QPLDLSVMHZLSFG-UHFFFAOYSA-N 0.000 description 1
- 239000005751 Copper oxide Substances 0.000 description 1
- 101100136092 Drosophila melanogaster peng gene Proteins 0.000 description 1
- 229910002668 Pd-Cu Inorganic materials 0.000 description 1
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 1
- 229910021536 Zeolite Inorganic materials 0.000 description 1
- DZVPMKQTULWACF-UHFFFAOYSA-N [B].[C].[N] Chemical compound [B].[C].[N] DZVPMKQTULWACF-UHFFFAOYSA-N 0.000 description 1
- 230000001133 acceleration Effects 0.000 description 1
- 239000013543 active substance Substances 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 238000005054 agglomeration Methods 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 230000003444 anaesthetic effect Effects 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 230000000711 cancerogenic effect Effects 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 231100000315 carcinogenic Toxicity 0.000 description 1
- 238000007084 catalytic combustion reaction Methods 0.000 description 1
- 210000003169 central nervous system Anatomy 0.000 description 1
- CETPSERCERDGAM-UHFFFAOYSA-N ceric oxide Chemical compound O=[Ce]=O CETPSERCERDGAM-UHFFFAOYSA-N 0.000 description 1
- 229910000420 cerium oxide Inorganic materials 0.000 description 1
- 229910000422 cerium(IV) oxide Inorganic materials 0.000 description 1
- 238000003889 chemical engineering Methods 0.000 description 1
- 229910000428 cobalt oxide Inorganic materials 0.000 description 1
- IVMYJDGYRUAWML-UHFFFAOYSA-N cobalt(ii) oxide Chemical compound [Co]=O IVMYJDGYRUAWML-UHFFFAOYSA-N 0.000 description 1
- 238000009841 combustion method Methods 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 229910000431 copper oxide Inorganic materials 0.000 description 1
- 238000005034 decoration Methods 0.000 description 1
- 239000007857 degradation product Substances 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- HNPSIPDUKPIQMN-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Al]O[Al]=O HNPSIPDUKPIQMN-UHFFFAOYSA-N 0.000 description 1
- 238000007598 dipping method Methods 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 238000004817 gas chromatography Methods 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 150000008282 halocarbons Chemical class 0.000 description 1
- 230000036541 health Effects 0.000 description 1
- 125000005842 heteroatom Chemical group 0.000 description 1
- 239000002638 heterogeneous catalyst Substances 0.000 description 1
- 239000002815 homogeneous catalyst Substances 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 1
- 238000005286 illumination Methods 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 231100001240 inorganic pollutant Toxicity 0.000 description 1
- 230000001788 irregular Effects 0.000 description 1
- 150000002576 ketones Chemical class 0.000 description 1
- 239000002649 leather substitute Substances 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 239000002091 nanocage Substances 0.000 description 1
- 239000011943 nanocatalyst Substances 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 229940078552 o-xylene Drugs 0.000 description 1
- 239000010815 organic waste Substances 0.000 description 1
- 238000010525 oxidative degradation reaction Methods 0.000 description 1
- BMMGVYCKOGBVEV-UHFFFAOYSA-N oxo(oxoceriooxy)cerium Chemical compound [Ce]=O.O=[Ce]=O BMMGVYCKOGBVEV-UHFFFAOYSA-N 0.000 description 1
- 229910052763 palladium Inorganic materials 0.000 description 1
- 239000000575 pesticide Substances 0.000 description 1
- 229910052698 phosphorus Inorganic materials 0.000 description 1
- 239000011574 phosphorus Substances 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 238000010926 purge Methods 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 239000000523 sample Substances 0.000 description 1
- 230000005476 size effect Effects 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 239000010457 zeolite Substances 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
- B01J37/02—Impregnation, coating or precipitation
- B01J37/024—Multiple impregnation or coating
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
- B01D53/86—Catalytic processes
- B01D53/8668—Removing organic compounds not provided for in B01D53/8603 - B01D53/8665
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J27/00—Catalysts comprising the elements or compounds of halogens, sulfur, selenium, tellurium, phosphorus or nitrogen; Catalysts comprising carbon compounds
- B01J27/24—Nitrogen compounds
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J35/00—Catalysts, in general, characterised by their form or physical properties
- B01J35/30—Catalysts, in general, characterised by their form or physical properties characterised by their physical properties
- B01J35/391—Physical properties of the active metal ingredient
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
- B01J37/16—Reducing
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2257/00—Components to be removed
- B01D2257/70—Organic compounds not provided for in groups B01D2257/00 - B01D2257/602
- B01D2257/708—Volatile organic compounds V.O.C.'s
-
- 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
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
- Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Environmental & Geological Engineering (AREA)
- Health & Medical Sciences (AREA)
- Biomedical Technology (AREA)
- Analytical Chemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Catalysts (AREA)
Abstract
The invention discloses a preparation method and application of a bimetallic single-atom-loaded BCN aerogel catalyst, belonging to the technical field of catalyst processing, wherein the preparation method comprises the following steps: firstly, preparing BCN aerogel, then taking the BCN aerogel as a carrier, sequentially loading two metals by an impregnation method, and calcining, wherein the sequential loading of the two metals is that noble metal is loaded firstly and non-noble metal is loaded secondly. The diatomic catalyst (DACs) is constructed by introducing a second metal, the catalytic activity and the change selectivity are improved by utilizing the synergistic effect of the double active centers or the multiple active centers of two metal atoms (homonuclear/heteronuclear), and on the basis of the advantages of the traditional SACs, the application limits of the SACs can be effectively broken, so that the activity of the catalyst and the stability and the selectivity of the catalytic reaction are improved, and the effective degradation of benzene VOCs is realized.
Description
Technical Field
The invention relates to the technical field of catalyst processing, in particular to a preparation method and application of a bimetallic single-atom-loaded BCN aerogel catalyst.
Background
Atmospheric pollutants are divided into particulate matters and gaseous matters, the gaseous matters are divided into organic pollutants and inorganic pollutants, wherein the organic pollutants account for most, and most of the organic pollutants are volatile organic matters (Volatile Organie Compounds), and are called VOCs for short, and the organic pollutants comprise various hydrocarbons, halogenated hydrocarbons, benzene, ketones and the like, wherein the benzene is widely applied to various industries, and industries for producing benzene organic waste gas mainly comprise petrochemical industry, organic chemical industry, pesticides, artificial leather, decoration home manufacturing industry and the like, so the benzene is a relatively common pollutant, the high-concentration benzene has anesthetic effect on central nervous system, some of the benzene even belongs to strong cancerogenic matters, and in addition, the benzene can be converted into O through a series of chemical reactions such as illumination and the like 3 PM2.5, photochemical smog, etc.,the purification treatment of benzene-based exhaust gas is a hot spot worldwide because of the harm to human health and ecological safety.
The treatment method for VOCs is mainly divided into two major categories, namely a recovery technology and a destruction technology, and a catalytic oxidation method in the destruction technology becomes a current research hot spot, and compared with the traditional thermal combustion method, the catalytic oxidation method has lower energy consumption and can thoroughly degrade the VOCs at a lower temperature. Researchers have increased the catalytic oxidation efficiency of VOCs by constructing highly active and stable catalysts, where metal-supported single-atom catalysts (SACs) have become a focus of research, which combine the advantages of both homogeneous and heterogeneous catalysts, i.e., high stability, ease of recovery, and a controlled coordination environment, but single-atom catalysts also face challenges such as: along with the increase of free energy of the surface of the monoatomic, the monoatomic is easy to gather in the preparation and catalysis processes, so that the reduction of the catalytic active site is caused, and the development and application of SACs are restricted; since SACs contain only one metal center, it is difficult to break the linear relationship that exists in many catalytic processes and cannot be applied to some reactions that require two or more active sites to activate the substrate; to avoid interatomic agglomeration, the metal loadings of most SACs are low, which also limits their practical use to a large extent. The prior art relies on means such as high temperature in the catalytic oxidation process, and the cost for degrading VOCs is also improved to a certain extent. Patent CN 104353459B discloses a supported bimetallic catalyst for catalytic oxidation of VOCs, a preparation method and application thereof, the catalyst takes titanium dioxide as a carrier, a first active component is ruthenium dioxide, a second active component is any one of manganese oxide, cobalt oxide, copper oxide or cerium oxide, even if the patent realizes that catalytic oxidation of benzene, phenol, o-xylene, chlorobenzene and 2-chlorophenol is completed through the synergistic effect of the two active components, and CO 2 The selectivity is more than or equal to 85 percent, but the catalytic oxidation temperature is 170-250 ℃, so that the degradation cost is increased.
In addition, carriers such as active carbon and titanium dioxide are adopted in the prior art for preparing the catalyst, the carriers are all required to be pretreated before active substances are loaded, the original pore channel structure of the carriers can be damaged in the treatment process, the loading of active components, the entering of gas and the like are influenced, and the conversion rate and the stability are further influenced.
Therefore, it is necessary to provide a catalyst capable of completing degradation of benzene-based VOCs under normal temperature conditions while improving degradation rate, conversion rate and stability thereof.
Disclosure of Invention
The invention aims to provide a preparation method and application of a bimetallic single-atom-supported BCN aerogel catalyst, which are used for solving the problems in the prior art, so that the obtained catalyst can be subjected to catalytic oxidation at normal temperature to finish degradation of benzene VOCs.
In order to achieve the above purpose, the invention adopts the following technical scheme:
a preparation method of a bimetallic single-atom-supported BCN aerogel catalyst comprises the following steps: firstly, preparing BCN aerogel, then taking the BCN aerogel as a carrier, sequentially loading two metals by an impregnation method, and calcining to obtain a bimetallic single-atom loaded BCN aerogel catalyst; the two metals are loaded in sequence, namely noble metal is loaded firstly, and non-noble metal is loaded secondly.
The invention constructs a double-atom catalyst (DACs) by introducing a second metal, and utilizes the synergistic effect of double active centers or multiple active centers of two metal atoms (homonuclear/heteronuclear), so that the catalytic activity can be improved, the selectivity can be changed, and compared with a single-atom catalyst (SACs), the quantity and the load of single-atom active sites are increased, and some application limits of the SACs can be effectively broken.
In the preparation method, the calcining temperature and the calcining time required for generating metal monoatoms based on different metal precursors are different, so that the two metal monoatoms can form strong and stable interaction with the carrier, and the two metal monoatoms are uniformly dispersed on the carrier, so that the two metals are sequentially loaded and calcined through an impregnation method; the two metals are loaded in sequence, namely noble metal is loaded firstly, and non-noble metal is loaded secondly.
Further, the method specifically comprises the following steps:
(1) Preparation of BCN aerogel
Adding urea and starch into boric acid solution, stirring uniformly, adding sodium chloride, standing to obtain a hydrogel precursor, heating the hydrogel precursor under the protection of inert gas, cooling, and grinding to obtain BCN aerogel;
(2) Loading noble metals
Immersing the BCN aerogel in a noble metal salt solution, adding citric acid, carrying out ultrasonic treatment, stirring, filtering, washing and drying to obtain a noble metal-loaded BCN aerogel semi-finished product;
(3) Calcination
Calcining the BCN aerogel semi-finished product loaded with the noble metal to obtain the BCN aerogel loaded with the noble metal;
(4) Loading non-noble metals
Immersing the BCN aerogel loaded with the noble metal in a non-noble metal salt solution, carrying out ultrasonic and light-shielding stirring, filtering, washing and drying to obtain a BCN aerogel semi-finished product loaded with the bimetal;
(5) Calcination
Calcining the BCN aerogel semi-finished product loaded with the bimetal to obtain the BCN aerogel catalyst loaded with the bimetal single atom.
Further, in the step (1), the mass ratio of the boric acid solution, urea and starch is 1:4:10, wherein the boric acid solution is prepared at present, and the mass ratio of the boric acid solution to urea and starch is calculated according to boric acid solid;
the mass ratio of urea to sodium chloride is 1: (1-3).
The beneficial effects are that: firstly, the direct irradiation of light can accelerate the reaction of the non-noble metal precursor solution and oxygen in the air, and in order to ensure that the added non-noble metal ions are uniformly and effectively loaded on the carrier, light-shielding stirring is adopted.
The BCN aerogel of the present invention then differs from other aerogel carriers in that: boric acid is used for providing a boron source, urea is used for providing a nitrogen source, and starch is used for providing a carbon source; the sodium chloride can induce starch containing a large amount of hydroxyl groups to form the three-dimensional hydrogel, the proportion of N, C elements in BCN aerogel is increased by increasing the proportion of urea and starch, the carrier structure can be more stable, the interaction between the carrier and metal species is enhanced, and the loading of the metal species is facilitated.
Further, in the step (2), the noble metal salt is H 2 PtCl 6 ·6H 2 O、AgNO 3 、PdCl 2 And HAuCl 4 ·4H 2 One of O;
the concentration of the noble metal salt solution is 0.05-0.2mol/L;
the addition amount of the citric acid is 1-5mL, and the concentration of the citric acid is 0.2mol/L.
The beneficial effects are as follows: according to the invention, the citric acid is added to reduce noble metal ions, so that the noble metal ions are prevented from being oxidized into ions with higher valence states by oxygen in the air, and the formation and uniform distribution of noble metal monoatoms are further promoted; too little citric acid is added to fully reduce metal ions, which can cause that part of metal ions are oxidized by air, thus being unfavorable for the formation of metal monoatoms and reducing the catalytic effect of the catalyst; too much citric acid can cause the pH of the metal precursor solution to be too low, well below the optimal pH for metal loading, thereby adversely affecting the activity of the catalyst.
Further, the calcining temperature in the step (3) is 400-800 ℃, and the calcining time is 2-6h.
Further, the non-noble metal salt in the step (4) is Ni (NO) 3 ) 2 ·6H 2 O、CoCl 2 、FeCl 3 ·6H 2 O and CuCl 2 ·2H 2 One of O;
the concentration of the non-noble metal salt is 0.05-0.2mol/L.
Further, the calcination temperature in the step (5) is 500-900 ℃ and the calcination time is 2-6h.
The beneficial effects are as follows: the optimal calcination temperatures for different metal loadings differ, so that two calcination steps are performed, the first calcination step supporting the noble metal on the surface of the support and the second calcination step supporting the non-noble metal on the surface of the support, in order to ensure that both the noble metal and the non-noble metal are better supported and form single atoms on the surface of the support. If calcined only once after loading the non-noble metal, it may result in a lower noble metal loading or formation of larger clusters, thereby decreasing the activity of the catalyst.
The BCN aerogel catalyst loaded with the bimetal single atoms prepared by the preparation method is characterized in that noble metals and non-noble metals are loaded on the BCN aerogel in an atomic-scale dispersion mode.
The application of the BCN aerogel catalyst loaded with the bimetallic single atom in degrading benzene VOCs.
Compared with the prior art, the invention has the beneficial effects that:
the invention can oxidize and degrade VOCs at normal temperature, and breaks through the inertia thinking of oxidative degradation of VOCs by adopting a normal-temperature catalytic oxidation technology (NTCO) due to the superior catalytic activity of an atomic-level metal active site catalyst, realizes thorough degradation of VOCs under the normal-temperature and normal-pressure conditions without high-temperature, high-pressure discharge and ultraviolet light, and the degradation product is pollution-free CO 2 And H 2 And O, the secondary pollution is effectively avoided.
According to the invention, a bimetallic single-atom-loaded BCN aerogel catalyst is adopted, and a BCN aerogel is used as a carrier, so that a bimetallic single-atom active site catalyst is constructed, a second metal is introduced to construct a double-atom catalyst (DACs), and the synergistic effect of double active centers or multiple active centers of two metal atoms (homonuclear/heteronuclear) is utilized to improve the catalytic activity and change the selectivity.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions of the prior art, the drawings that are needed in the embodiments will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a scanning electron microscope image of the support BCN aerogel of example 1, wherein (a) is an SEM image of the BCN aerogel of example 1 at a 1 μm scale and (b) is an SEM image of the BCN aerogel of example 1 at a 500nm scale;
FIG. 2 is a scanning electron microscope image of a BCN aerogel catalyst loaded with an atomically dispersed noble metal Pt in example 1;
FIG. 3 is a scanning electron microscope image of a BCN aerogel catalyst supporting atomically dispersed bi-metal monoatoms in example 1;
FIG. 4 is a flow chart of the preparation of a bimetallic single-atom supported BCN aerogel catalyst in example 1;
FIG. 5 is a graph comparing catalytic effects of different catalysts;
FIG. 6 is a graph comparing the catalytic effects of the different catalysts of comparative example 8.
Detailed Description
Various exemplary embodiments of the invention will now be described in detail, which should not be considered as limiting the invention, but rather as more detailed descriptions of certain aspects, features and embodiments of the invention.
It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. In addition, for numerical ranges in this disclosure, it is understood that each intermediate value between the upper and lower limits of the ranges is also specifically disclosed. Every smaller range between any stated value or stated range, and any other stated value or intermediate value within the stated range, is also encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.
Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference for the purpose of disclosing and describing the methods and/or materials associated with the documents. In case of conflict with any incorporated document, the present specification will control.
It will be apparent to those skilled in the art that various modifications and variations can be made in the specific embodiments of the invention described herein without departing from the scope or spirit of the invention. Other embodiments will be apparent to those skilled in the art from consideration of the specification of the present invention. The specification and examples are exemplary only.
As used herein, the terms "comprising," "including," "having," "containing," and the like are intended to be inclusive and mean an inclusion, but not limited to.
The normal temperature in the examples of the present invention means 25.+ -. 2 ℃.
Example 1
A preparation method of a bimetallic single-atom-supported BCN aerogel catalyst comprises the following steps:
(1) Preparation of BCN aerogel
Will be 0.5g H 3 BO 3 Adding 10mL of deionized water, carrying out ultrasonic treatment at 30 ℃ for 10min to obtain a boric acid solution, sequentially adding 2g of urea and 5g of starch into the boric acid solution, stirring uniformly to form white slurry, pouring 5g of sodium chloride, starting adhesion of the white slurry, standing in air at normal temperature for 4h to obtain a hydrogel precursor, heating the hydrogel precursor to 800 ℃ under nitrogen flow (40 mL/min) for 4h, and grinding to obtain BCN aerogel, wherein a scanning electron microscope image is shown in figure 1.
(2) Loading noble metals
5g of the ground BCN aerogel was impregnated with 1.5mL of H at a concentration of 0.1mol/L 2 PtCl 6 ·6H 2 Adding 2mL of citric acid aqueous solution with the concentration of 0.2mol/L into the O aqueous solution, carrying out ultrasonic treatment on the mixed solution, wherein the ultrasonic frequency is 40KHz, the ultrasonic time is 0.5h, and then stirring for 5h at room temperature; and finally, filtering, washing and drying at 60 ℃ for 12 hours to obtain a BCN aerogel semi-finished product loaded with the noble metal Pt dispersed in an atomic level.
(3) Calcination
Calcining the semi-finished product of the BCN aerogel loaded with the noble metal Pt dispersed in the atomic level at 600 ℃ for 4 hours to obtain the BCN aerogel loaded with the noble metal Pt dispersed in the atomic level, wherein a scanning electron microscope image is shown in figure 2.
(4) Loading non-noble metals
Impregnating BCN aerogel loaded with noble metal Pt dispersed in atomic scale in 2mL of CoCl with concentration of 0.1mol/L 2 Carrying out ultrasonic treatment in aqueous solution, wherein the ultrasonic frequency is 40KHz, the ultrasonic time is 40min, then stirring for 12h at 60 ℃ in a dark place, finally filtering, washing, and drying for 10h at 60 ℃ to obtain the BCN aerogel semi-finished product carrying the atomically dispersed bimetal.
(5) Calcination
Calcining the semi-finished product of the BCN aerogel loaded with the atomically dispersed bimetal at 700 ℃ for 3 hours to obtain the BCN aerogel catalyst loaded with the atomically dispersed bimetal single atom, which is marked as Pt-Co/BCN, and a scanning electron microscope image is shown in figure 3.
The specific preparation flow is shown in figure 4.
Example 2
A preparation method of a bimetallic single-atom-supported BCN aerogel catalyst comprises the following steps:
(1) Preparation of BCN aerogel
Will be 0.5g H 3 BO 3 Adding 10mL of deionized water, carrying out ultrasonic treatment at 30 ℃ for 20min to obtain a boric acid solution, sequentially adding 2g of urea and 5g of starch into the boric acid solution, stirring uniformly to form white slurry, pouring 6g of sodium chloride, starting adhesion of the white slurry, standing in the air at normal temperature for 4h to obtain a hydrogel precursor, heating the hydrogel precursor to 800 ℃ under the flow of nitrogen (40 mL/min), and grinding for 4h to obtain the BCN aerogel.
(2) Loading noble metals
5g of the ground BCN aerogel was impregnated with 1.5mL of 0.15mol/LAgNO 3 Adding 1mL of citric acid aqueous solution with the concentration of 0.15mol/L into the aqueous solution, carrying out ultrasonic treatment on the mixed solution, wherein the ultrasonic frequency is 50KHz, the ultrasonic time is 40min, and then stirring for 4h at room temperature; finally filtering, washing and drying for 10 hours at 70 ℃ to obtain the BCN aerogel loaded with the noble metal Ag dispersed in atomic scaleAnd (5) a semi-finished product.
(3) Calcination
Calcining the BCN aerogel semi-finished product loaded with the noble metal Ag dispersed in the atomic level at 650 ℃ for 4 hours to obtain the BCN aerogel loaded with the noble metal Ag dispersed in the atomic level.
(4) Loading non-noble metals
BCN aerogel loaded with noble metal Ag dispersed in atomic scale is immersed in 2mL of Ni (NO) with concentration of 0.1mol/L 3 ) 2 ·6H 2 And (3) carrying out ultrasonic treatment in an O aqueous solution, wherein the ultrasonic frequency is 40KHz, the ultrasonic time is 0.5h, then stirring for 10h at 50 ℃ in a dark place, finally filtering, washing, and drying for 10h at 80 ℃ to obtain the BCN aerogel semi-finished product carrying the atomically dispersed bimetal.
(5) Calcination
Calcining the semi-finished product of the BCN aerogel loaded with the atomically dispersed bimetal at 600 ℃ for 4 hours to obtain the BCN aerogel catalyst loaded with the atomically dispersed bimetal single atom, which is denoted as Ag-Ni/BCN.
Example 3
A preparation method of a bimetallic single-atom-supported BCN aerogel catalyst comprises the following steps:
(1) Preparation of BCN aerogel
Will be 0.5g H 3 BO 3 Adding 10mL of deionized water, carrying out ultrasonic treatment at 30 ℃ for 0.5h to obtain a boric acid solution, sequentially adding 2g of urea and 5g of starch into the boric acid solution, stirring uniformly to form white slurry, pouring 5g of sodium chloride, starting adhesion of the white slurry, standing in air for 4h to obtain a hydrogel precursor, heating the hydrogel precursor to 800 ℃ under the flow of nitrogen (40 mL/min), and grinding for 4h to obtain the BCN aerogel.
(2) Loading noble metals
5g of the ground BCN aerogel was impregnated with 1mL of 0.1mol/LHAuCl 4 ·4H 2 Adding 2mL of citric acid aqueous solution with the concentration of 0.1mol/L into the O aqueous solution, carrying out ultrasonic treatment on the mixed solution, wherein the ultrasonic frequency is 40KHz, the ultrasonic time is 0.5h, and then stirring for 6h at room temperature; finally, filtering and washingAnd drying at 80 ℃ for 8 hours to obtain a BCN aerogel semi-finished product loaded with the noble metal Au dispersed in atomic scale.
(3) Calcination
Calcining the BCN aerogel semi-finished product loaded with the noble metal Au dispersed in the atomic scale at 700 ℃ for 3 hours to obtain the BCN aerogel loaded with the noble metal dispersed in the atomic scale.
(4) Loading non-noble metals
Impregnating BCN aerogel loaded with atomically dispersed noble metal Au into 2mL of FeCl with concentration of 0.05mol/L 3 ·6H 2 And (3) in an O aqueous solution, carrying out ultrasonic treatment, wherein the ultrasonic frequency is 50KHz, the ultrasonic time is 0.5h, then stirring for 8h at 70 ℃ in a dark place, finally filtering, washing, and drying for 9h at 80 ℃ to obtain the BCN aerogel semi-finished product carrying the atomically dispersed bimetal.
(5) Calcination
Calcining the semi-finished product of the BCN aerogel loaded with the atomically dispersed bimetal at the temperature of 500 ℃ for 4 hours to obtain the BCN aerogel catalyst loaded with the atomically dispersed bimetal single atom, which is named as Au-Fe/BCN.
Example 4
A preparation method of a bimetallic single-atom-supported BCN aerogel catalyst comprises the following steps:
(1) Preparation of BCN aerogel
Will be 0.5g H 3 BO 3 Adding 10mL of deionized water, carrying out ultrasonic treatment at 30 ℃ for 0.5h to obtain a boric acid solution, sequentially adding 2g of urea and 5g of starch into the boric acid solution, stirring uniformly to form white slurry, pouring 5g of sodium chloride, starting adhesion of the white slurry, standing in air for 4h to obtain a hydrogel precursor, heating the hydrogel precursor to 800 ℃ under the flow of nitrogen (40 mL/min), and grinding for 4h to obtain the BCN aerogel.
(2) Loading noble metals
5g of the ground BCN aerogel was impregnated with 1mL of PdCl at a concentration of 0.05mol/L 2 Adding 2mL of citric acid aqueous solution with concentration of 0.1mol/L into the aqueous solution, performing ultrasonic treatment on the mixed solution with ultrasonic frequency of 40KHz for 0.5h, and then placing in a roomStirring for 6h under the temperature condition; and finally, filtering, washing and drying for 8 hours at 80 ℃ to obtain the BCN aerogel semi-finished product loaded with the noble metal Pd dispersed in the atomic level.
(3) Calcination
Calcining the semi-finished product of the BCN aerogel loaded with the noble metal Pd dispersed in the atomic level at 400 ℃ for 6 hours to obtain the BCN aerogel loaded with the noble metal Pd dispersed in the atomic level.
(4) Loading non-noble metals
Impregnating BCN aerogel catalyst loaded with atomically dispersed noble metal Pd in 2mL of CuCl with concentration of 0.15mol/L 2 ·2H 2 And (3) in an O aqueous solution, carrying out ultrasonic treatment, wherein the ultrasonic frequency is 50KHz, the ultrasonic time is 30min, then stirring for 8 hours at 70 ℃ in a dark place, finally filtering, washing, and drying for 9 hours at 80 ℃ to obtain a BCN aerogel semi-finished product carrying the atomically dispersed bimetal.
(5) Calcination
Calcining the semi-finished product of the BCN aerogel loaded with the atomically dispersed bimetal at 900 ℃ for 6 hours to obtain the BCN aerogel catalyst loaded with the atomically dispersed bimetal single atom, which is named Pd-Cu/BCN.
Example 5
A preparation method of a bimetallic single-atom-supported BCN aerogel catalyst comprises the following steps:
(1) Preparation of BCN aerogel
Will be 0.5g H 3 BO 3 Adding 10mL of deionized water, carrying out ultrasonic treatment at 30 ℃ for 10min to obtain a boric acid solution, sequentially adding 2.5g of urea and 4g of starch into the boric acid solution, stirring uniformly to form white slurry, pouring 5g of sodium chloride, starting adhesion of the white slurry, standing in air at normal temperature for 4h to obtain a hydrogel precursor, heating the hydrogel precursor to 800 ℃ under nitrogen flow (40 mL/min), and grinding for 4h to obtain BCN aerogel.
(2) Loading noble metals
5g of the ground BCN aerogel was immersed in 1mL of AgNO at a concentration of 0.2mol/L 3 Adding 2mL of 0.25mol/L citric acid aqueous solution into the aqueous solution, and adding the mixed solutionPerforming ultrasonic treatment with ultrasonic frequency of 40KHz for 20min, and stirring at room temperature for 4 hr; and finally, filtering, washing and drying for 10 hours at 80 ℃ to obtain a BCN aerogel semi-finished product loaded with the atomically dispersed noble metal Ag.
(3) Calcination
Calcining the BCN aerogel semi-finished product loaded with the noble metal Ag dispersed in the atomic level at 800 ℃ for 2 hours to obtain the BCN aerogel loaded with the noble metal Ag dispersed in the atomic level.
(4) Loading non-noble metals
Impregnating BCN aerogel loaded with atomically dispersed noble metal Ag in 4mL of CoCl with concentration of 0.2mol/L 2 And (3) performing ultrasonic treatment in an aqueous solution, wherein the ultrasonic frequency is 40KHz, the ultrasonic time is 30min, then stirring for 12 hours at 60 ℃ in a dark place, finally filtering, washing, and drying for 12 hours at 80 ℃ to obtain a BCN aerogel semi-finished product carrying the atomically dispersed bimetal.
(5) Calcination
Calcining the semi-finished product of the BCN aerogel loaded with the atomically dispersed bimetal at the temperature of 500 ℃ for 2 hours to obtain the BCN aerogel catalyst loaded with the atomically dispersed bimetal single atom, which is denoted as Ag-Co/BCN.
Example 6
A preparation method of a bimetallic single-atom-supported BCN aerogel catalyst comprises the following steps:
(1) Preparation of BCN aerogel
Will be 0.5g H 3 BO 3 Adding 10mL of deionized water, carrying out ultrasonic treatment at 30 ℃ for 10min to obtain a boric acid solution, sequentially adding 2g of urea and 5g of starch into the boric acid solution, stirring uniformly to form white slurry, pouring 5g of sodium chloride, starting adhesion of the white slurry, standing in air at normal temperature for 3h to obtain a hydrogel precursor, heating the hydrogel precursor to 800 ℃ under nitrogen flow (40 mL/min), and grinding to obtain BCN aerogel after 4 h.
(2) Loading noble metals
5g of the ground BCN aerogel was immersed in 1mL of 0.2mol/LH 2 PtCl 6 ·6H 2 O aqueous solutionAdding 2mL of citric acid aqueous solution with the concentration of 0.15mol/L, carrying out ultrasonic treatment on the mixed solution, wherein the ultrasonic frequency is 40KHz, the ultrasonic time is 25min, and then stirring for 5h at room temperature; and finally, filtering, washing and drying for 12 hours at 60 ℃ to obtain the BCN aerogel semi-finished product loaded with the noble metals dispersed in the atomic level.
(3) Calcination
Calcining the BCN aerogel semi-finished product loaded with the noble metal Pt dispersed in the atomic level at 600 ℃ for 4 hours to obtain the BCN aerogel loaded with the noble metal Pt dispersed in the atomic level.
(4) Loading non-noble metals
Impregnating BCN aerogel loaded with atomically dispersed noble metal Pt in 2mL of FeCl with concentration of 0.2mol/L 3 ·6H 2 And (3) in an O aqueous solution, carrying out ultrasonic treatment, wherein the ultrasonic frequency is 40KHz, the ultrasonic time is 30min, then stirring for 10 hours at 70 ℃ in a dark place, finally filtering, washing, and drying for 10 hours at 80 ℃ to obtain a BCN aerogel semi-finished product carrying the atomically dispersed bimetal.
(5) Calcination
Calcining the semi-finished product of the BCN aerogel loaded with the atomically dispersed bimetal at the temperature of 700 ℃ for 3 hours to obtain the BCN aerogel catalyst loaded with the atomically dispersed bimetal single atom, which is named as Pt-Fe/BCN.
Comparative example 1
The only difference from example 1 is that a BCN aerogel catalyst supporting only noble metal Pt was prepared by the following steps:
(1) Preparation of BCN aerogel
Will be 0.5g H 3 BO 3 Adding 10mL of deionized water, carrying out ultrasonic treatment at 30 ℃ for 10min to obtain a boric acid solution, sequentially adding 2g of urea and 5g of starch into the boric acid solution, stirring uniformly to form white slurry, pouring 5g of sodium chloride, starting adhesion of the white slurry, standing in the air at normal temperature for 4h to obtain a hydrogel precursor, heating the hydrogel precursor to 800 ℃ under the flow of nitrogen (40 mL/min), and grinding for 4h to obtain the BCN aerogel.
(2) Loading noble metals
5g of the ground BCN aerogel was impregnated with 1.5mL of H at a concentration of 0.1mol/L 2 PtCl 6 ·6H 2 Adding 2mL of citric acid aqueous solution with the concentration of 0.2mol/L into the O aqueous solution, carrying out ultrasonic treatment on the mixed solution, wherein the ultrasonic frequency is 40KHz, the ultrasonic time is 0.5h, and then stirring for 5h at room temperature; and finally, filtering, washing and drying at 60 ℃ for 12 hours to obtain a BCN aerogel semi-finished product loaded with the noble metal Pt dispersed in an atomic level.
(3) Calcination
Calcining the BCN aerogel semi-finished product loaded with the noble metal Pt dispersed in the atomic level at 600 ℃ for 4 hours to obtain the BCN aerogel catalyst loaded with the noble metal Pt dispersed in the atomic level, which is named as Pt/BCN.
Comparative example 2
The only difference from example 1 is that a BCN aerogel catalyst supporting only non-noble metal Co was prepared by the following steps:
(1) Preparation of BCN aerogel
Will be 0.5g H 3 BO 3 Adding 10mL of deionized water, carrying out ultrasonic treatment at 30 ℃ for 10min to obtain a boric acid solution, sequentially adding 2g of urea and 5g of starch into the boric acid solution, stirring uniformly to form white slurry, pouring 5g of sodium chloride, starting adhesion of the white slurry, standing in the air at normal temperature for 4h to obtain a hydrogel precursor, heating the hydrogel precursor to 800 ℃ under the flow of nitrogen (40 mL/min), and grinding for 4h to obtain the BCN aerogel.
(2) Loading non-noble metals
5g of the ground BCN aerogel was impregnated with 2mL of CoCl at a concentration of 0.1mol/L 2 Carrying out ultrasonic treatment in aqueous solution, wherein the ultrasonic frequency is 40KHz, the ultrasonic time is 40min, then stirring for 12h at 60 ℃ in a dark place, finally filtering, washing, and drying for 10h at 60 ℃ to obtain the BCN aerogel semi-finished product of the non-noble metal Co loaded with atomic-level dispersion.
(3) Calcination
Calcining the BCN aerogel semi-finished product loaded with the atomically dispersed non-noble metal Co for 3 hours at the temperature of 700 ℃ to obtain the BCN aerogel catalyst loaded with the atomically dispersed non-noble metal Co, which is denoted as Co/BCN.
Comparative example 3
The difference from example 1 is only that the order of loading the metals is adjusted, i.e. loading the non-noble metals first and then loading the noble metals.
Comparative example 4
Mixing the noble metal solution and the non-noble metal solution in the embodiment 1, dipping the ground BNC aerogel in the mixed solution, adding 2mL of 0.2mol/L citric acid, stirring for 12h in a dark place, filtering, washing, drying for 12h at 60 ℃, calcining once only, and calcining for 4h at 600 ℃ to obtain the BCN aerogel loaded with the noble metal Pt dispersed in an atomic scale.
Comparative example 5
The difference from example 1 is only that no citric acid solution was added in step (2).
Comparative example 6
The procedure is as in example 1, except that the stirring in step (4) is not carried out in the absence of light.
Comparative example 7
The same as in example 1, the BCN aerogel carrier was replaced with activated carbon, and noble metal and non-noble metal were successively supported, to obtain a bimetallic single-atom-supported activated carbon catalyst different from that of example 1.
Comparative example 8
The only difference from example 1 is that only five metals were prepared as follows: the 5 kinds of metals are loaded on the BCN aerogel catalyst of Ni, fe, cu, pd, pt with the same 0.5wt% loading, so that catalysts Ni/BCN, fe/BCN, cu/BCN, pd/BCN and Pt/BCN are respectively obtained, and the benzene removal effect of the catalysts is examined.
TABLE 1
Experimental conditions: the initial reaction concentration of benzene is 500mg/m 3 The mass space velocity is 50000 mL/(gh), the air flow is 100mL/min, the reaction temperature is 70 ℃, the benzene removal effect is shown in FIG. 6, and the noble metal loading is shown in FIG. 6The catalyst has better benzene removal effect than a catalyst loaded with non-noble metals, wherein the catalyst removal rate of the catalyst loaded with Pt can reach 100%.
Comparative example 9
The preparation method of the carrier BCN aerogel is the same as that of the preparation method and application of the carrier BCN aerogel in the embodiment 1 of the invention, and the preparation method and application of the carrier BCN aerogel are the same as those of the three-dimensional porous boron carbon nitrogen material in the patent CN 108341404B.
The performance detection process of the bimetallic BCN aerogel catalyst comprises the following steps: benzene is used as a probe, and the catalytic activity of the catalyst is evaluated by a self-assembled VOCs normal-temperature catalytic evaluation device and an online gas chromatography detection method (FID GC-7080). The diameter of the reactor is 8mm, three paths of gases are mixed in a mixing tank and then are introduced into the reactor, one path is air provided by an air pump, and the other two paths are N 2 One path blows out benzene through the VOCs blowing bottle, and the other path brings out water vapor through the water vapor bubbling bottle. The benzene vapor generation temperature is controlled to be 1-5 ℃ by adopting a circulating refrigerator. By controlling air, purging benzene N 2 Flow rate and benzene production temperature to adjust benzene inlet concentration (C in ) The method comprises the steps of carrying out a first treatment on the surface of the Controlling the reaction space velocity by controlling the air flow and the catalyst charge mass (weight hourly space velocity WHSV); by controlling the N entering the water vapor bubbling bottle 2 The flow rate was used to adjust the relative humidity of the reaction (relative humidity RH). The reacted gas was split into two paths, one path was fed into a gas chromatograph to monitor the benzene outlet concentration (C out ) The other path is vented to atmosphere. The degradation effect of the BCN aerogel catalyst loaded with the bimetallic single atoms and the Pt/BCN aerogel catalyst on benzene is shown in figure 5.
The degradation conditions and results of the benzene-based VOCs in the above examples and comparative examples are shown in Table 2, and the catalyst evaluation conditions are as follows: the initial concentration of benzene is 1000mg/m 3 Space velocity is 30000 mL/(g.h), relative humidity is 25%; reaction temperature: 25 ℃.
TABLE 2
As can be seen from table 2: comparative examples 1-2 carried only one metal and had a significant decrease in conversion and degradation rate of 100% for a period of time compared to example 1, probably because the loading of only one metal resulted in a smaller number of active sites, thereby decreasing catalyst reactivity; compared with example 1, in comparative example 3, the conversion rate and degradation rate of the non-noble metal supported before the noble metal supported are reduced, and the supported noble metal may have an acceleration effect on the non-noble metal supported, so that after the loading sequence of the two metals is changed, the loading amounts of the noble metal and the non-noble metal are reduced, and the catalytic performance of the catalyst is reduced; compared with example 1, in comparative example 4, precious metals and non-precious metals are mixed and then loaded together, the conversion rate and the degradation rate of the mixed materials are reduced obviously for 100% of the duration of the mixed materials after calcination only once, the loading conditions and the optimal calcination temperature of the two metals are different, and the loading efficiency of the two metals is greatly reduced at the same time; compared with the embodiment 1, the citric acid solution is not added in the step (2) in the comparative example 5, the conversion rate and the degradation rate are both obviously reduced for 100%, and the citric acid is not used to cause oxidation of metal ions by oxygen in the air, which is not beneficial to the loading of the metal ions; compared with the example 1, the comparative example 6, in which the step (4) is stirred without light, has a reduced conversion rate and degradation rate of 100% for a certain period of time, accelerates the reaction of the metal precursor solution and the components in the air under direct sunlight to cause deterioration, and reduces the metal loading efficiency; compared with example 1, the conversion rate and degradation rate of the carrier are both obviously reduced for 100% in comparison with the carrier replacement in example 7, which indicates that the interaction force between the conventional active carbon carrier and the load metal is possibly weakened due to the lack of B, N and other heteroatoms, so that the reactive sites are reduced, and the catalytic performance is reduced. The degradation rate, duration and number of repeated use of comparative example 9 were inferior to example 1, because of the analysis: the surface of the carrier BCN aerogel obtained by the method is in an irregular phosphorus sheet shape and is accompanied by a multi-concave structure, so that the loading capacity and the uniform distribution of metal ions are effectively improved, and a better catalytic effect is obtained.
The effect of the bimetallic single-atom-supported BCN aerogel catalysts prepared in some examples and comparative examples of the present invention on catalyzing the oxidation of benzene-based VOCs is compared with other catalysts is shown in table 3.
TABLE 3 Table 3
Note that: 1 is Metal Support Interaction in Pt Nanoparticles Partially Confined in the Mesopores of Microsized Mesoporous CeO 2 for Highly Efficient Purification of Volatile Organic Compounds, mao M, acs Catalysis, pages 418-427; 2 is Preparation of size-controlled Pt supported on Al 2 O 3 nanocatalysts for deep catalytic oxidation of benzene at lower temperature, chen Z, applied Surface Science, page 465; 3 is Rare Earth-Modified kallin/NaY-Supported Pd-Pt Bimetallic Catalyst for the Catalytic Combustion of Benzene, zuo S, acs Applied Materials&Interfaces, pages 11988-11996; 4 are Tricobalt tetraoxide-supported palladium catalyst derived from metal organic frameworks for complete benzene oxidation, li J, catalysis Letters, pages 1300-1308; 5 is Excellent low temperature performance for total benzene oxidation over mesoporous CoMnAl composited oxides from hydrotalcites, mo S, journal of Materials Chemistry, pages 8113-8122; 6 is Size effect of Pt nanoparticles on the catalytic oxidation of toluene over Pt/CeO2 catalysts, peng R S, applied Catalysis B-Environmental, pages 462-470; 7 is Enhanced toluene combustion performance over Pt loaded hierarchical porous MOR zeolite, zhang J, chemical Engineering Journal, page 334; 8 is Metal-organic frameworks-derived hierarchical Co 3 O 4 CoNi-layered double oxides nanocages with the enhanced catalytic activity for toluene oxidation, wu Z, chemosphere, page 280; 9 is Gold supported on metal oxides for volatile organic compounds total oxidation, carabineiro S A C, catalysis Today, pages 103-114.
As can be seen from table 2: the degradation effect of benzene series VOCs by using BCN as a carrier is obviously better than that of benzene series VOCs by using other carriers, the advantages of adjustable porosity, large surface area and the like of the BCN aerogel material can be benefited, and the doping of B, N can lead the supported metal to be dispersed more uniformly, form a metal-N or metal-B coordination bond so as to anchor the metal, and further improve the catalytic activity of the catalyst.
Meanwhile, the catalytic activity of the bimetallic catalyst is obviously superior to that of a single-metal catalyst in the prior art, and the reason is probably that the synergistic effect of double active centers or multiple active centers of two metal atoms (homonuclear/heteronuclear) improves the catalytic activity and the change selectivity, and compared with a single-atom catalyst (SACs), the bimetallic catalyst has the advantages of increasing the number and the load of single-atom active sites and being capable of effectively breaking some application limitations existing in SACs.
The foregoing description of the preferred embodiments of the invention is not intended to limit the invention to the particular embodiments disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.
Claims (5)
1. The application of the BCN aerogel catalyst loaded with the bimetal single atoms is characterized in that the BCN aerogel catalyst loaded with the bimetal single atoms is used for degrading benzene-based VOCs;
the benzene VOCs are degraded under normal temperature and normal pressure conditions without high temperature, high voltage discharge and ultraviolet light;
the preparation method of the BCN aerogel catalyst loaded with the bimetal single atoms comprises the following steps:
(1) Preparation of BCN aerogel
Adding urea and starch into boric acid solution, stirring uniformly, adding sodium chloride, standing to obtain a hydrogel precursor, heating the hydrogel precursor under the protection of nitrogen, cooling, and grinding to obtain BCN aerogel;
(2) Loading noble metals
Immersing the BCN aerogel in a noble metal salt solution, adding citric acid, carrying out ultrasonic treatment, stirring, filtering, washing and drying to obtain a noble metal-loaded BCN aerogel semi-finished product;
(3) Calcination
Calcining the noble metal-loaded BCN aerogel semi-finished product to obtain noble metal-loaded BCN aerogel;
(4) Loading non-noble metals
Immersing the BCN aerogel loaded with the noble metal in a non-noble metal salt solution, carrying out ultrasonic and light-shielding stirring, filtering, washing and drying to obtain a BCN aerogel semi-finished product loaded with the bimetal;
(5) Calcination
Calcining the bimetal-loaded BCN aerogel semi-finished product to obtain a bimetal single-atom-loaded BCN aerogel catalyst;
in the step (1), the mass ratio of boric acid to urea to starch is 1:4:10;
the mass ratio of urea to sodium chloride is 1: (1-3).
2. The use of a bimetallic single-atom-supported BCN aerogel catalyst as claimed in claim 1, wherein said noble metal salt in step (2) is H 2 PtCl 6 ·6H 2 O、AgNO 3 、PdCl 2 And HAuCl 4 ·4H 2 One of O;
the concentration of the noble metal salt solution is 0.05-0.2mol/L.
3. The use of a bimetallic monoatomic supported BCN aerogel catalyst according to claim 1, wherein the calcination temperature in step (3) is 400-800 ℃ and the calcination time is 2-6h.
4. The use of a bimetallic single-atom-supported BCN aerogel catalyst as claimed in claim 1, wherein said non-noble metal salt in step (4) is Ni (NO 3 ) 2 ·6H 2 O、CoCl 2 、FeCl 3 ·6H 2 O and CuCl 2 ·2H 2 One of O;
the concentration of the non-noble metal salt is 0.05-0.2mol/L.
5. The use of a bimetallic monoatomic supported BCN aerogel catalyst according to claim 1, wherein the calcination temperature in step (5) is 500-900 ℃ and the calcination time is 2-6h.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211022983.XA CN115155647B (en) | 2022-08-25 | 2022-08-25 | Preparation method and application of BCN aerogel catalyst loaded with bimetallic single atoms |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211022983.XA CN115155647B (en) | 2022-08-25 | 2022-08-25 | Preparation method and application of BCN aerogel catalyst loaded with bimetallic single atoms |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115155647A CN115155647A (en) | 2022-10-11 |
| CN115155647B true CN115155647B (en) | 2023-04-28 |
Family
ID=83480581
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211022983.XA Active CN115155647B (en) | 2022-08-25 | 2022-08-25 | Preparation method and application of BCN aerogel catalyst loaded with bimetallic single atoms |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115155647B (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112371149A (en) * | 2020-10-23 | 2021-02-19 | 江苏大学 | Preparation method and application of tungsten oxide confinement-supported boron carbon nitrogen nanotube catalyst material |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110449174B (en) * | 2019-07-03 | 2022-02-08 | 天津大学 | Preparation method of supported nitrogen-oxygen co-doped porous carbon atomic-level active site catalyst |
| CN110639548B (en) * | 2019-09-19 | 2022-06-14 | 北京工业大学 | Monoatomic palladium-cobalt bimetallic nano-catalyst for efficiently catalyzing benzene oxidation |
| CN114515604A (en) * | 2020-11-20 | 2022-05-20 | 中国科学院大连化学物理研究所 | Quaternary phosphonium salt polymer loaded bimetallic monatomic catalyst, preparation method and application |
| KR102471909B1 (en) * | 2020-12-24 | 2022-11-29 | 성균관대학교산학협력단 | Water splitting catalyst |
| CN114592211A (en) * | 2022-02-28 | 2022-06-07 | 西安交通大学 | Composite material with BCN (bulked continuous carbon) nanotubes loaded with rhodium phosphide nanoparticles as well as preparation method and application of composite material |
-
2022
- 2022-08-25 CN CN202211022983.XA patent/CN115155647B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112371149A (en) * | 2020-10-23 | 2021-02-19 | 江苏大学 | Preparation method and application of tungsten oxide confinement-supported boron carbon nitrogen nanotube catalyst material |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115155647A (en) | 2022-10-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Gao et al. | Mesoporous molecular sieve-based materials for catalytic oxidation of VOC: A review | |
| Song et al. | Advances in catalytic oxidation of volatile organic compounds over Pd-supported catalysts: recent trends and challenges | |
| JP2020507445A (en) | Transition metal and nitrogen co-doped carbon composite material used for formaldehyde purification and its preparation method | |
| CN109107567A (en) | A kind of M-MnOx-CeO2Catalyst and its application | |
| CN108816233A (en) | A kind of preparation method of the copper-cobalt composite oxide catalysts for benzene catalysis oxidation | |
| CN114618589B (en) | Preparation method and application of ozone degradation catalyst based on iron-based organic framework | |
| CN112246250B (en) | Integral catalytic combustion catalyst and preparation method and application thereof | |
| WO2022194306A1 (en) | Composite catalyst and method for treating nitrogen-containing volatile organic composite pollutants | |
| CN110773158A (en) | Material for room-temperature catalytic purification of VOCs (volatile organic compounds) based on metal monoatomic atoms and preparation method thereof | |
| KR20110088613A (en) | Catalyst composit for vocs oxidation and preparation process thereof | |
| CN113797935A (en) | Catalyst for low-temperature efficient treatment of VOCs and preparation method thereof | |
| CN113210010B (en) | VOC catalyst coated in different areas and preparation method thereof | |
| CN115445651A (en) | Pure silicon molecular sieve supported palladium catalyst for methane catalytic combustion and preparation method thereof | |
| CN113751023B (en) | Bimetallic-based catalyst for low-temperature high-selectivity catalytic oxidation of ammonia, preparation method and application thereof | |
| CN110605118B (en) | Integral Pd/K for degrading formaldehyde at room temperature2Ti6O13-NWs catalyst, preparation method and application | |
| CN115155647B (en) | Preparation method and application of BCN aerogel catalyst loaded with bimetallic single atoms | |
| CN115318286B (en) | Platinum catalyst for catalytic combustion of propane and preparation method and application thereof | |
| CN114471695B (en) | Catalyst capable of efficiently degrading cyanide-containing waste gas and preparation method and application thereof | |
| CN111468172B (en) | Metal oxide-silver bifunctional catalyst for formaldehyde waste gas purification treatment and preparation method thereof | |
| CN115722220A (en) | Catalytic oxidation catalyst, and preparation method and application thereof | |
| CN113101923A (en) | Mn-Zr-La-Ce catalyst for degrading VOCs (volatile organic compounds), preparation method and low-temperature plasma concerted catalysis application thereof | |
| CN113181951A (en) | Preparation of carbon nitride modified copper-loaded cerium-zirconium solid solution catalyst and application of carbon nitride modified copper-loaded cerium-zirconium solid solution catalyst in catalytic oxidation of toluene | |
| CN112892554A (en) | Two-dimensional layered material with diatomic active phase and preparation method and application thereof | |
| CN115414963B (en) | Catalyst for removing VOCs and preparation method and application thereof | |
| CN114160184B (en) | Preparation method and application of silver-cerium bimetallic molecular sieve catalyst for catalyzing and oxidizing VOCs (volatile organic compounds) in cooperation with ozone |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |