68 results about "Reduction Activity" patented technology

The application discloses a platinum-based high-entropy intermetallic compound and a preparation method and application thereof as a hydrogen fuel cell cathode catalyst, and belongs to the field of fuel cells.The preparation method comprises the following steps: S01, adding platinum salt, at least five other metal salts and a nitrogen-rich organic compound into an organic solvent, uniformly mixing, and obtaining a metal precursor mixed solution; S02, adding a carbon carrier into the metal precursor mixed solution, fully mixing, drying, collecting, and obtaining a precursor; and S03, heat treating the dried precursor under a reducing atmosphere, and performing heat preservation treatment, so as to obtain the platinum-based high-entropy intermetallic compound.The preparation method is simple, low in cost and good in repeatability, the prepared catalyst has the advantages of uniform particle size and high oxygen reduction activity, and has a good development prospect in the field of hydrogen fuel cell catalyst applications.

The invention discloses a covalent organic framework with oxidation-reduction activity and a bionic nano-channel structure as well as a preparation method and application of the covalent organic framework, and belongs to the technical field of environmental protection. According to the preparation method, 2, 4-dihydroxybenzene-1, 3, 5-tricarboxaldehyde and 2, 5-bis (allyloxy) terephthaloyl hydrazine are taken as raw materials, a two-dimensional covalent organic framework with oxidation-reduction activity is synthesized, and then a sulfonic acid group with negative charges is covalently grafted, so that a functional material with a bionic nano-channel structure is formed. The material has regular porous channels and rich functional sites, the porous channels provide efficient mass transfer paths and adsorption spaces for uranyl ions, and the functional sites realize specific recognition of the uranyl ions through oxidation-reduction reaction and electrostatic interaction, so that the material shows synergistic advantages of strong selectivity, high adsorption capacity and rapid adsorption kinetics on uranium. The method is simple and low in cost, and the prepared material is clear in structure, good in hydrophilicity, capable of efficiently adsorbing uranyl ions and good in application prospect.

The invention discloses a nickel-tin alloy-oxide composite material Ni3Sn2-NiSnOx, a preparation method thereof and application of the nickel-tin alloy-oxide composite material Ni3Sn2-NiSnOx in electrocatalytic ammonia synthesis reaction, and belongs to the technical field of electrochemical catalysis. The preparation method comprises the following steps: adding SnCl2. 2H2O and NiCl into deionized water as raw materials, adding glycine, potassium pyrophosphate and urea as electro-deposition auxiliary agents, and stirring for 10 minutes to obtain electro-deposition liquid; and carrying out electro-deposition on a conductive substrate serving as a cathode, so that Ni and Sn are co-deposited to form a nickel-tin alloy, and part of the nickel-tin alloy reacts with oxygen in the deposition process or after deposition to form a nickel-tin oxide phase, so that the Ni3Sn2-NiSnOx composite catalytic material is obtained. By regulating and controlling the concentration of tin ions in the electroplating solution and the electrodeposition time, the component proportion of nickel and tin in the product and the morphology structure of the material can be regulated. The composite material provided by the invention has excellent electrocatalytic nitrogen reduction synthesis ammonia activity and selectivity, and solves the problems that the service life of a catalyst is shortened and the catalytic activity and stability are reduced due to irreversible reconstruction of an alloy compound under high potential.

The invention provides a fluorine-doped Fe-N-C composite material as well as a preparation method, application and regeneration thereof, and belongs to the technical field of water pollution. The preparation method comprises the following steps: firstly, mixing an iron precursor, zinc salt, an organic ligand and an organic solvent to synthesize a Fe-doped metal organic framework Fe (at) ZIF-8 material, and then carbonizing the Fe-doped metal organic framework Fe (at) ZIF-8 material into a Fe-N-C material; and then Fe-N-C and a fluorine source are mixed and subjected to secondary carbonization, and the fluorine-doped Fe-N-C composite material is obtained. Fluorine atoms are introduced into the Fe-N-C material and generate axial coordination with Fe in the center of FeN4, the fluorine element with high electronegativity can effectively improve the isoelectric point of the Fe-N-C material, the reaction activity of the material is enhanced, Fe leaching of the material in the reaction process is inhibited, and the stability of the material is improved. In addition, the prepared fluorine-doped Fe-N-C composite material can continue to be recycled through fluorine doping regeneration, and high reduction activity and stability are kept.

The invention provides a carbon layer coated NiFe nanoparticle difunctional composite electrocatalyst as well as a preparation method and application thereof, and belongs to the technical field of new energy materials. A transition metal organic framework compound with specific morphology and size is synthesized from dimethyl imidazole and transition metal salt, then a nitrogen-doped carbon material (Fe-N-C) with specific morphology and high oxygen reduction activity (ORR) and containing transition metal iron is prepared through pyrolysis, the Fe-N-C material is physically mixed with a nickel precursor and an iron precursor, and the nitrogen-doped carbon material is prepared. And the composite difunctional electrocatalyst with high ORR and oxygen evolution reaction (OER) performance of the NiFe nanoparticles coated with the carbon layer is obtained under a microwave heating condition, and can be applied to a metal-air battery as a cathode catalyst.

The invention belongs to the field of environmental biotechnology and nano material application, and relates to a method for accelerating microorganisms to reduce selenite based on immobilized riboflavin. Aiming at the problems of poor stability, difficulty in recovery, non-repeated use and the like of dissolved riboflavin serving as an electron shuttle, riboflavin is grafted on the surface of a multi-walled carbon nanotube through a covalent binding method, and immobilized riboflavin capable of being recycled is constructed. The material can accelerate extracellular electron transfer of shewanella MR-1, and toxic sodium selenite is efficiently reduced into low-toxicity or non-toxic elemental selenium. Results show that the immobilized riboflavin not only maintains high reduction activity of riboflavin, but also has excellent cyclic utilization performance, still maintains high reduction rate after being repeated for multiple times, and effectively reduces operation cost and resource loss. According to the invention, an efficient, economical and sustainable application scene is provided for a microorganism-electron shuttle combined remediation technology, and a new thought is also provided for application of a functional nano material in an environmental biotechnology.

The invention discloses screening of novel multifunctional selenite reductase SDR-SerA, and belongs to the field of environmental pollutants. A novel multifunctional enzyme capable of reducing selenite is screened from a gene bank in a selenium-rich region, and the reduction activity of the enzyme to S-1-phenylethanol is further represented. According to the invention, selenite reductase is mutated, and site-specific mutagenesis and molecular dynamics (MD) simulation reveal that the mutant M206 affects a lid opening and closing mechanism of an enzyme active site. The novel selenite reductase is reported from a short-chain dehydrogenase / reductase (SDR) superfamily, and a novel method is provided for finding the novel selenite reductase from a wide enzyme library of the novel selenite reductase. The research not only deepens the understanding of the selenium metabolism process, but also lays a foundation for developing an efficient selenium pollution bioremediation technology.

The application provides a fluorine-doped Fe-N-C composite material and a preparation method and application and regeneration thereof, and belongs to the technical field of water pollution. In the application, an iron precursor, a zinc salt, an organic ligand and an organic solvent are mixed to synthesize Fe-doped metal organic framework Fe@ZIF-8 material, and then the Fe@ZIF-8 material is carbonized into Fe-N-C material; then the Fe-N-C material is mixed with a fluorine source and subjected to secondary carbonization to obtain the fluorine-doped Fe-N-C composite material. In the application, fluorine atoms are introduced into the Fe-N-C material to produce axial coordination with Fe of the FeN4 center, the fluorine element with high electronegativity can effectively improve the isoelectric point of the Fe-N-C material, the reaction activity of the material is enhanced, the Fe leaching of the material in the reaction process is inhibited, and the stability of the material is improved. In addition, the prepared fluorine-doped Fe-N-C composite material can be reused through fluorine-doping regeneration, and high reduction activity and stability can be maintained.

The invention discloses a nickel-phosphine co-doped molybdenum disulfide composite material as well as a preparation method and application thereof. According to the method, nickel ions and organic phosphonic acid molecules are co-doped into the structure of molybdenum disulfide, and the nickel-phosphine co-doped molybdenum disulfide composite material with high stability and catalytic performance is prepared by fully utilizing the good conductivity of molybdenum disulfide, the chemical modification function of organic phosphonic acid and the strong oxidation-reduction activity of the nickel ions. The composite material shows excellent catalytic performance in the aspect of catalytically activating peroxymonosulfate to oxidize and degrade organic pollutants, can effectively degrade the organic pollutants in wastewater, and has the advantages of mild reaction conditions, high degradation rate, high catalytic stability, high pollution resistance, high reusability and wide application prospect.

The invention belongs to the technical field of electro-catalysis, and particularly relates to an electrode for synthesizing RT base as well as a preparation method and application thereof. The electrode comprises a substrate and active components loaded on the surface of one side of the substrate, wherein the active components comprise copper and lanthanum. The electrode is a solid polymer (SPE) electrode, active components of copper and lanthanum are loaded on the surface of a substrate, a catalyst is arranged on the electrode at zero interval, and power consumption is greatly reduced. According to the present invention, the active component copper has high selectivity, the lanthanum can improve the catalytic activity and the durability and the service life of the electrode, the electrode is used for synthesizing the RT base, the reduction activity of the electrode is high, the use stability is strong, and the efficient and stable performance can be maintained during the long-time electrolysis process.

The invention discloses a composite catalyst as well as a preparation method and application thereof. The composite catalyst comprises carbon nitride, cobalt sulfide and phosphorus. The composite catalyst provided by the invention utilizes the synergistic effect between carbon nitride and cobalt sulfide to regulate the electron and chemical structure of an active center and promote the generation and migration of photo-generated charges at the same time. The surface of the catalyst is modified by phosphorus, so that adsorption and activation of reactants CO2 and H2O molecules can be further promoted. According to the preparation method of the composite catalyst, the synthesis strategy is regulated and controlled, the cobalt sulfide is uniformly dispersed on the carrier, and the reduction activity and stability of carbon dioxide are improved. The catalyst is low in price, the preparation process is simple, the repeatability is good, and large-scale production is easy to carry out.

The invention provides an atomic-scale Ag cluster functionalized MOF (Metal Organic Framework)-based composite electrocatalyst as well as a preparation method and application thereof. The catalyst is named as Ag (at) MOF-Ag4-2Ph. The catalyst is prepared by a one-step method at room temperature, and the specific steps are as follows: stirring a mixed solution of a triazole derived ligand, silver nitrate and ammonia water at 25 DEG C, centrifuging the reaction solution after the reaction is finished, and performing vacuum drying to obtain the electrocatalyst. The catalyst has superfine Ag nano-particles generated by triazole derived ligands in situ, Ag monatomic and Ag4 atomic cluster active sites, and the three components have a synergistic effect, so that excellent electrocatalytic CO2 reduction activity is realized. The catalyst can realize full-pH electrolysis and maintain high selectivity and high current density to CO in an extremely wide voltage range. The method is an Ag-based industrial-grade high-performance electrocatalyst which is green, simple and convenient to synthesize and easy to produce on a large scale, a green example is established for an industrial CO2 electrolysis system, and the method has important practical application value in the aspects of industrial flue gas CO2 recovery and the like.

The invention discloses a zirconium-doped nano zero-valent metal composite material as well as a preparation method and application thereof. The preparation method comprises the following step: in an aqueous solution, reacting transition metal salt with a zirconium source under the action of a reducing agent to prepare the zirconium-doped nano zero-valent metal composite material. The zirconium-doped nano zero-valent metal composite material is prepared through a liquid-phase in-situ reduction coprecipitation method, and the composite material has extremely high stability while showing excellent oxidation-reduction activity. Meanwhile, the composite material can be used as a Fenton-like catalyst to efficiently treat wastewater polluted by the organic chelating agent.

The invention belongs to the technical field of polymer electrolyte membrane fuel cells, and provides preparation and application of a template-assisted derived electrocatalyst, metal macrocyclic compound self-assembly is performed on the surface of a metal organic framework material to form an ordered aggregate, and then high-temperature heat treatment is performed on the composite to prepare the corresponding electrocatalyst. The electrocatalyst prepared by the method does not form metal-based particles after being subjected to high-temperature heat treatment, so that metal aggregation is effectively avoided, the metal-nitrogen-carbon oxygen reduction active site density is improved, and the electrocatalyst has better oxygen reduction activity and stability in acidic and alkaline electrolytes. The preparation process of the catalyst adopted in the method does not need any acid treatment, the raw materials are rich in source, resources are saved, the cost is reduced, meanwhile, the preparation process of the non-noble metal electrocatalyst is simplified, and the prepared electrocatalyst has high oxygen reduction activity and durability and can be used in the field of polymer electrolyte membrane fuel cells.

The invention discloses an Ag / Cu2O / g-C3N4 heterojunction photocatalyst as well as a preparation method and application thereof, and belongs to the technical field of photocatalytic materials. The Ag / Cu2O / g-C3N4 heterojunction photocatalyst is prepared from the following components in percentage by mass: 10 to 30 percent of Cu2O. A g-C3N4 precursor prepared through a solvothermal reaction is fired into a nanotube shape in a tubular furnace, then Ag is generated in situ through heating and stirring, finally the Ag / Cu2O / g-C3N4 heterojunction photocatalyst is synthesized through heating and stirring, and the Ag / Cu2O / g-C3N4 heterojunction photocatalyst can be applied to the field of photocatalytic reduction of CO2. Compared with an existing photocatalyst, the Ag / Cu2O / g-C3N4 heterojunction has good yield and stability, and a strong built-in electric field at the heterojunction interface can accelerate separation and transfer of carriers and enhance adsorption and activation of CO2, so that the activity of photocatalytic reduction of CO2 is enhanced.

The present invention discloses a novel composite heterojunction photocatalyst, a preparation method thereof, and its application in carbon dioxide reduction. The photocatalyst is prepared by a hydrothermal method using WCl6 as the tungsten source, thioacetamide (TAA) as the sulfur source, cobalt phthalocyanine as the CoPc source, phosphoric acid (H3PO4) as the phosphoric acid source, and deionized water (H2O) as the solvent. The prepared (CoPc-P / WS2) photocatalyst has a spherical structure with a diameter of about 500 nm, and the surface contains rich functional groups, and it exhibits excellent photocatalytic CO2 reduction activity under visible light.

The present invention provides a Bi 2‑x Eu x WO6 / Nb2C MXene photothermal material and its preparation method and application, the preparation method comprises: dissolving Bi(NO3)3, Eu(NO3)3 and Na2WO4 in ethylene glycol to obtain a reaction precursor solution, performing a hydrothermal reaction to obtain Bi 2‑ x Eu x WO6; Nb2C MXene powder was dispersed in ethanol to obtain suspension A; Bi 2‑x Eu x WO6 was dispersed in ethanol to obtain suspension B; suspension A and suspension B were irradiated with ultraviolet light respectively, then suspension A was slowly added to suspension B, and the obtained mixed suspension was irradiated with ultraviolet light to obtain Bi 2‑x Eu x WO6 / Nb2C MXene photothermal material. 2‑x Eu x WO6 / Nb2C MXene photothermal material improves the photothermal catalytic CO2 reduction activity and methane selectivity.

The invention belongs to the technical field of catalysts, and particularly relates to a CoS / CuCo2S4 photocatalyst as well as a preparation method and application thereof. The preparation method comprises the following steps: respectively dissolving Co (NO3) 2.6 H2O and Cu (NO3) 2.3 H2O in ethylene glycol to respectively obtain a first solution and a second solution; dropwise adding the second solution into the first solution while stirring to obtain a third solution; the preparation method comprises the following steps: adding CuCo2S4 into a reaction kettle, continuously stirring, then adding sodium dimethyl dithiocarbamate to obtain a suspension, and carrying out hydrothermal reaction, washing and drying to obtain the CoS / CuCo2S4 photocatalyst. According to the invention, a CS / CCS hollow spherical II-type heterostructure with rich sulfur vacancies and interface Co-S bond connection is constructed through a one-step hydrothermal method. An interface Co-S bond serves as an atomic channel to effectively promote separation and transmission of photon-generated carriers, a large number of photo-generated electrons are enriched on the surface of CCS and stably exist at active sites, and therefore the CO2 photo-reduction activity is improved.

The invention discloses a BiOCl / TiO2 photocatalyst prepared by an electrochemical method as well as a preparation method and application thereof, and the preparation method of the BiOCl / TiO2 photocatalyst comprises the following steps: 1) placing a Ti sheet subjected to surface pretreatment in an aqueous solution containing F <-> for anodic oxidation, and then placing the Ti sheet in a muffle furnace for heat treatment to obtain an anatase type TiO2 nanotube; 2) taking the TiO2 nanotube as a working electrode, and obtaining Bi nanocrystals in a water solution containing Bi (NO3) 3 with a certain concentration, lignin calcium benzenesulfonate and an emulsifier OP-10 by adopting a pulse electrodeposition method; 3, the sample with the Bi nanocrystals deposited is subjected to electrooxidation in a Cl <-> solution under the specific pH condition, and the BiOCl / TiO2 photocatalyst is obtained.The BiOCl / TiO2 photocatalyst prepared through the electrochemical method has the advantages of being stable in structure, high in CO2 photocatalytic reduction activity and high in product selectivity.

The invention particularly relates to a medium-entropy alloy material, a preparation method thereof, a modified electrode containing the medium-entropy alloy material, an electrochemical sensor containing the medium-entropy alloy material and application. The preparation method of the medium-entropy alloy material comprises the following steps that three metal elementary substance raw materials are mixed according to the molar ratio of 1: 1: 1, the mixture is placed in a vacuum smelting furnace to be smelted, and the medium-entropy alloy material is obtained; the three metal elementary substance raw materials are any three of Ni, Al, Mo, Fe, Cr, Al and Co. The modified electrode comprises a substrate electrode and the medium-entropy alloy material, and the medium-entropy alloy material is modified on the surface of the substrate electrode. The invention also provides application of the modified electrode in an electrochemical sensor and the electrochemical sensor containing the modified electrode. The medium-entropy alloy material shows good catalytic reduction activity on p-nitrophenol, and an electrochemical sensor constructed based on the medium-entropy alloy material is applied to detection of p-nitrophenol, so that a good analysis effect is achieved.

This invention belongs to the fields of catalytic chemistry and fine chemicals, and discloses a halogen-modified supported noble metal catalyst and its application in the synthesis of oxaragoli key intermediates. The catalyst uses alumina or modified alumina as a support, loads the active component (noble metal), and modifies its surface electronic structure through halide ions. The preparation method includes precursor conversion of the support, impregnation and reduction of the active metal, and post-modification and regulation of halide ions. The catalyst obtained by this invention exhibits excellent hydrogenation reduction activity and selectivity for compounds containing C=N or C≡N bonds under mild conditions. Under room temperature and low-pressure hydrogen conditions, this catalyst can efficiently catalyze the conversion of 2-fluoro-6-trifluoromethylbenzaldehyde oxime to the oxaragoli key intermediate 2-fluoro-6-trifluoromethylbenzylamine, showing promising industrial application prospects.

The invention belongs to the technical field of heavy metal wastewater treatment and environmental restoration, and discloses a method for efficiently reducing and removing hexavalent chromium (Cr (VI)) based on the synergistic effect of a plant-derived soluble organic matter (DOM, a water-soluble organic carbon compound passing through a 0.45-micron filter membrane) and a low-temperature freezing technology. According to the method, the plant source DOM is combined with freezing and thawing cycles for the first time, the reduction activity is enhanced through organic molecule protonation in an acid environment, the local concentration of Cr (VI) and DOM is increased by 10-100 times through low-temperature (lower than or equal to-15 DEG C) freezing, and the reaction rate is increased by 2-3 orders of magnitude. Experiments show that under the conditions that DOM is equal to 15.0 mg / L, pH is equal to 3.0 and freezing and thawing are performed for 2-3 times, the removal rate of Cr (VI) within 30 minutes reaches 99.7%, the efficiency is improved by 75% compared with normal-temperature treatment, and the effluent concentration is lower than 0.5 mg / L. The method does not need additional reagents, utilizes agricultural wastes, has high efficiency, low cost and environmental friendliness, is suitable for chromium-containing wastewater treatment in electroplating, leather making and the like, and has high efficiency, economical efficiency and ecological friendliness.

The invention discloses an aggregation-induced emission photocatalyst as well as a preparation method and application thereof, and belongs to the technical field of preparation of compounds. The structural formula of the aggregation-induced emission photocatalyst is as shown in formula I, wherein R1 is F or Cl; r2 is a diphenylamino group, a substituted diphenylamino group, a triphenylamino group or a substituted triphenylamino group; and R3 is Br, a substituted diphenylamino group, a triphenylamino group or a substituted triphenylamino group. The photocatalyst has visible light absorption, aggregation enhanced luminescence and reduction activity. According to the preparation method, a 4, 7-dibromobenzothiadiazole derivative and aromatic amine are subjected to Buchwald or Suzuki reaction, and the condition is mild. The catalyst is used for metal-free light-operated atom transfer radical polymerization, can efficiently catalyze the polymerization of acrylate monomers under the irradiation of a blue light or green light LED with a low dosage of 5-100 ppm, realizes high conversion rate, narrow distribution and block synthesis, is suitable for an aqueous phase system, and has good biocompatibility and large-scale prospects.

The invention discloses a supported Mn-based catalyst and a preparation method and application thereof, the catalyst takes a Y-type molecular sieve with high crystallinity, large specific surface area and large pore volume as a carrier, and manganese with outstanding low-temperature redox activity, low price and low toxicity is selected as a supported metal. And the catalyst is used for treating VOCs, so that the emission of VOCs is reduced, and toluene is subjected to catalytic oxidation. The manganese element is loaded on the Y-type molecular sieve, the supercage aperture of the Y-type molecular sieve is matched with that of toluene molecules, MnOx can be confined into a highly dispersed cluster of 2-3 nm, sufficient active sites are exposed, and sintering is inhibited; the strong acidity and exchangeable skeleton oxygen cooperate to promote toluene adsorption-activation, the lattice oxygen migration rate is high, the material has good hydrothermal stability and regeneration performance, and long-period operation is guaranteed without inactivation. And the toluene conversion rate of the catalyst can reach 100% within 1 hour under the condition of low load of manganese metal.

The present invention belongs to the technical field of photocatalysts, and discloses a Cu 1.95 S 1‑x photocatalyst with surface Cu and S dual defect sites, its preparation method and application. By adding cetyltrimethylammonium bromide and hexamethylenetetramine to an ethylene glycol solution containing copper element, adding a certain amount of thioacetamide, stirring for a certain time at a certain temperature and then pouring it into a reaction kettle, and carrying out hydrothermal reaction at a certain temperature for a certain time, after washing and drying, a Cu 1.95 S 1‑x photocatalyst with surface Cu and S dual defect sites is obtained. The specific surface area of the photocatalyst prepared by the present invention is larger, and it has higher photocatalytic activity. In particular, the photocatalytic reduction activity of CO2 is enhanced, and the preparation method of the catalyst reduces the production cost and simplifies the production process. The prepared Cu 1.95 S 1‑x photocatalyst with surface Cu and S dual defect sites can photocatalytically reduce CO2 to CH4.

The invention relates to the technical field of photocatalysts, in particular to a metal complex / covalent organic framework hybrid photocatalyst as well as a preparation method and application thereof. The preparation method comprises the following steps: preparing TPT-COF solid powder; the preparation method comprises the following steps: uniformly dispersing bipyridine and a cobalt source in an organic solvent, and stirring to form a complex solution; then adding the TPT-COF solid powder obtained in the step S1, stirring for reaction, and washing and drying to obtain the metal complex / covalent organic framework hybrid photocatalyst. The catalyst has a highly ordered two-dimensional porous structure, wide spectral response capability, excellent carrier transport performance and a stable metal coordination structure, shows enhanced CO2 reduction activity under irradiation of visible light, can be repeatedly used for 3-10 times or more on the premise that the performance is not obviously reduced, has catalytic activity maintained to be not lower than 80%, and has good application prospects. Good structural stability and reaction reproducibility are shown.

The invention discloses a Ba / Ho co-doped lanthanum strontium cobalt-based perovskite cathode material and a preparation method and application thereof, and belongs to the technical field of solid oxide fuel cell cathode materials, the chemical general formula of the Ba / Ho co-doped lanthanum strontium cobalt-based perovskite cathode material is ABO3-delta, A is La, Sr, Ba and Ho; the B site is Co; the molar ratio of the La to the Sr to the Ba to the Ho to the Co is (0.1 to 0.5) to (0.1 to 0.5) to (0.1 to 0.5) to (0.05 to 0.2) to 1; 0 < = [delta] lt; 3. The cathode material obtained by the preparation method of the Ba / Ho co-doped lanthanum strontium cobalt-based perovskite cathode material shows a pure phase of a perovskite structure, and has relatively high oxygen reduction activity, relatively low polarization resistance and excellent Cr and CO2 poisoning resistance.

The application discloses a preparation method of a low-noble-metal heterojunction fuel cell catalyst, which comprises the following steps: (1) preparing Pt-Co alloy nanoparticles; (2) preparing a cobalt acetate ethanol solution, placing the Pt-Co alloy nanoparticles in the cobalt acetate ethanol solution, stirring, growing a cobalt acetate film layer on the outer surface of the Pt-Co alloy nanoparticles, and obtaining the low-noble-metal heterojunction fuel cell catalyst. The preparation method can effectively reduce the use of Pt, reduce the preparation cost of the catalyst, and is suitable for large-scale application. The low-noble-metal heterojunction fuel cell catalyst has high oxygen reduction activity and can effectively improve the catalytic reaction efficiency.

The application belongs to the technical field of catalytic materials, and discloses a preparation method and application of a double cobalt atom catalyst. The target catalyst Co2-DAC is prepared through the steps of mixed liquid preparation, preheating dropwise adding, constant temperature refluxing and post-treatment purifying, and the reaction condition is mild, inert gas protection is not needed, the process is simple, and the cost is relatively low. The prepared catalyst takes double cobalt atoms as the active center, the atoms are uniformly dispersed, and the structure is stable. With the synergistic effect of the double active sites, the charge transport and CO2 activation performance can be improved, the catalyst shows high activity and stability in the photocatalytic CO2 reduction reaction, can effectively convert CO2 into high value-added products, and provides guidance for designing double atom catalysts with high photocatalytic CO2 reduction activity.

The invention relates to a cathode catalyst with a controllable core-shell structure and a preparation method and application thereof, and belongs to the technical field of fuel cell catalysts. The preparation method of the cathode catalyst with the controllable core-shell structure comprises the following steps: dispersing a Fe-N-C inner core in a Tris-HCl buffer solution, adding dopamine hydrochloride DA-HCl, stirring and polymerizing at room temperature, centrifugally collecting a black solid, washing with water for multiple times, and drying a precipitate in a vacuum oven to constant weight to obtain polydopamine PDA coated powder PDA coated Fe-N-C; and pyrolyzing the PDA-coated Fe-N-C powder, and naturally cooling to obtain the cathode catalyst with the core-shell structure. The catalyst prepared by the invention successfully avoids the problem of activity reduction caused by a traditional coating method, and does not significantly hinder the mass transfer process while providing physical protection. The prepared catalyst shows excellent long-term stability in actual fuel cell operation on the basis of maintaining high oxygen reduction activity.