39 results about "Pt nanoparticles" patented technology

The invention discloses a Pt-based composite nanoparticle catalyst as well as a preparation method and application thereof, the catalyst comprises a V5O12 carrier and Pt nanoparticles loaded on the carrier, and the V5O12 is of a multi-stage layered nanoflower structure; the catalyst is obtained by in-situ generation of Pt nanoparticles on a V5O12 carrier. According to the catalyst disclosed by the invention, the superfine Pt nano-particles are loaded on the metal oxide V5O12, so that the activity and the stability of the catalyst are improved; in addition, the preparation method is simple to operate and low in cost, and large-scale production can be realized.

This invention relates to the field of ceramic materials and their preparation technology, and particularly to a Pt-doped perovskite ceramic composite material, its preparation method, and its application. The Pt-doped perovskite ceramic composite material provided by this invention uses platinum (Pt) as the dopant phase, and combines a sol-gel assisted doping method with a two-step sintering process using solid-state methods to uniformly distribute Pt in nanoparticle form on Sm... 0.5 Sr 0.5 The ZrO3 ceramic grain boundary region (forming a grain boundary nano-Pt phase) enhances near-infrared reflectivity and reduces thermal radiation absorption while maintaining the stability of the main phase lattice. This invention reduces the thermal conductivity of the ceramic composite material while improving its high-temperature stability through the interfacial regulation effect of the grain boundary nano-Pt phase. This invention also significantly improves the toughness and crack resistance of Pt-doped perovskite ceramic composite materials by constructing Pt nanoparticles to "pinneck" cracks at the ceramic grain boundaries, thus overcoming the intrinsic brittleness of ceramic materials.

The application relates to a preparation method and application of a supported platinum-rhodium-copper core-shell nanometer alloy electrocatalyst. The preparation method comprises the following steps: mixing raw materials containing a platinum source, a copper source and a rhodium source, a surfactant and an oleylamine solvent to obtain a mixed solution; the mixed solution is heated to 160-280 DEG C and reacts for 0.5-8 h, and then is cooled; the cooled reaction solution is washed with acetic acid and centrifuged at a speed of not less than 8000 r / min; a product, namely platinum-rhodium-copper alloy nanoparticles, which does not contain the surfactant on the surface, is obtained; the amount of the acetic acid is not less than the volume of the reaction solution; the obtained product and the platinum source are put into the oleylamine solvent, mixed, heated, reacted, cooled and centrifuged to obtain PtRhCu@Pt nanoparticles; the PtRhCu@Pt nanoparticles are mixed with a carbon carrier to obtain a PtRhCu@Pt catalyst. The catalyst prepared by the preparation method has high coating degree of the platinum shell layer on the surface and uniform particle size.

This invention discloses a Pt / O-NCP catalyst and its preparation method. It utilizes self-developed nanoporous carbon (NCP) as a support, which is modified to change the internal pores from a hydrophobic to a hydrophilic state. A special preparation method is then used to obtain the noble metal catalyst Pt / O-NCP. During catalyst loading, most Pt nanoparticles are located within the mesopores of the support, maximizing the direct contact between the polymer and Pt (sulfonic acid poisoning). This solves the problems in existing catalysts where Pt nanoparticles are prone to dissolution and carbon corrosion under voltage fluctuations, leading to Pt growth and aggregation, thus avoiding the reduction in catalytic performance caused by a decrease in the active surface area of ​​the catalyst. Furthermore, this catalyst can also address the significant decrease in overpotential of ordinary carbon support materials under low humidity, resolving the typical performance degradation of PEMFCs under low humidity conditions.

The application discloses a hollow spherical composite catalyst Pt / MnO2 / MnCo2O4, wherein the MnCo2O4 is a hollow sphere with a spinel structure composed of manganese and cobalt double transition metal oxides, the diameter of the hollow sphere is distributed in 1-2 mu m, and the hollow sphere has a porous structure with many cavities in the inside. MnO2 nanosheet microspheres are uniformly attached to the MnCo2O4, and the diameter of the MnO2 nanosheet microspheres is 95-105 nm. Pt nanoparticles with a particle size of 2-20 nm are uniformly loaded on the MnCo2O4 and the MnO2. The Pt / MnO2 / MnCo2O4 is synthesized by a solvothermal method and calcination in an air bath to synthesize a hollow spherical MnCo2O4 carrier, and then the MnO2 and the Pt nanoparticles are loaded on the surface of the MnCo2O4 by a deposition-precipitation method and an in-situ reduction method. The hollow spherical composite catalyst can catalyze degradation of tetracycline in polluted water at room temperature, and the catalytic efficiency can still be maintained after repeated use.

This invention discloses a platinum-tungsten carbide-graphene layered cathode hydrogen evolution catalyst, its preparation method, and its application, belonging to the field of proton exchange membrane electrolysis for hydrogen production. The catalyst has a layered structure, formed by graphene, a tungsten carbide layer grown in situ on the graphene surface, and noble metal nanoparticles. The graphene forms a two-dimensional conductive network, the tungsten carbide layer is the intermediate layer, and the noble metal nanoparticles are the active centers; wherein the noble metal nanoparticles are Pt nanoparticles, Ru nanoparticles, or Ir nanoparticles. By utilizing the high-speed electron channel provided by graphene, the tungsten carbide layer as the electronic regulation and physical anchoring layer for the noble metal, and the noble metal nanoparticles as the final active centers, the three work synergistically to achieve high activity, high stability, and low noble metal usage.

This paper discloses a 3d transition metal M-rare earth metal R bicomponent carbon-supported Pt catalyst, its preparation method, and its application. It relates to the catalyst supported on carbon doped with Pt, its preparation method, and its application. This catalyst aims to address the poor catalytic activity and stability of existing Pt / C catalysts. The catalyst consists of Pt nanoparticles supported on an M-R bicomponent carbon support, where M is Fe, Co, Ni, or Zn, and R is Ce, Nd, or Gd. Preparation method: M and R ions are complexed with a nitrogen source ligand on a carbon surface and then carbonized at high temperature to obtain the M-R bicomponent carbon support. Then, Pt is loaded using a microwave reduction method to obtain the M-R bicomponent carbon-supported Pt catalyst. The mass activities of Pt / Fe-Ce-NC and Pt / Co-Ce-NC are 0.27 and 0.22 A / mg, respectively. Pt It is 2.8 and 2.3 times that of Pt / C, and can be used in the field of proton exchange membrane fuel cells.

The application belongs to the field of batteries, and particularly relates to a Pt / S-TiO 2‑x @Ti self-supporting electrode and a preparation method thereof, nitrate electroreduction ammonia production application and Zn-NO3 ‑ Battery; the Pt / S-TiO 2‑x @Ti self-supporting electrode comprises a titanium substrate, an oxygen-defect titania array in-situ grown on the surface of the titanium substrate, and Pt nanoparticles and S atoms doped in the oxygen-defect titania array; wherein the oxygen defects and the S atoms construct a blocked Lewis acid-base pair; the Pt nanoparticles mediate the formation of a reverse hydrogen overflow channel. The electrode disclosed by the application can have excellent NO3 ‑ RR activity and selectivity, in addition, the material can effectively adapt to the characteristics of the Zn-NO3 ‑ Battery, and can exhibit excellent electrochemical performance.

The invention discloses a method for preparing a Pt / La2O2CO3 nano-catalyst from La2O2CO3 loaded Pt nano-particles and application of the catalyst, and relates to the technical field of nano-catalyst preparation, the preparation method comprises the following steps: synthesizing a La2O2CO3 single carrier La2O2CO3-S or synthesizing a La2O3 and La2O2CO3 mixed carrier La2O2CO3-M; preparing a Pt colloid; the preparation method comprises the following steps: preparing a Pt / La2O2CO3-S catalyst or a Pt / La2O2CO3-M catalyst with different Pt loading capacities by adopting a colloidal deposition method; the prepared Pt / La2O2CO3-S catalyst and the prepared Pt / La2O2CO3-M catalyst are used for catalyzing CO2 hydrogenation to prepare CO. The preparation method has the beneficial effects that the preparation process of the catalyst is simple and convenient, the Pt / La2O2CO3-S catalyst and the Pt / La2O2CO3-M catalyst have relatively high catalyst activity, selectivity and stability, and the problems of relatively low activity and stability of a Pt-based catalyst at high temperature in a reaction for preparing CO by catalyzing CO2 hydrogenation and the like are solved.

This invention discloses a photopolymerizable piezoelectric ceramic with ultra-high energy harvesting performance, its preparation method, and its applications, relating to the field of piezoelectric ceramic technology. The method includes adding PIN-PMN-PZ-PT nanoparticles to a surface modification solution, followed by ball milling to obtain surface-functionalized PIN-PMN-PZ-PT nanoparticles; designing a three-dimensional structural model with a complex three-dimensional periodic structure; feeding the PIN-PMN-PZ-PT-based piezoelectric ceramic slurry into the feed tank of a photopolymerizer, importing the three-dimensional structural model into the photopolymerizer, setting printing parameters, and printing to obtain a green body; and debinding and sintering the green body to obtain the piezoelectric ceramic. This invention, by combining different photopolymerizable monomer resins, produces single-layer sheets with high strength and good toughness, and optimizes the optimal photoinitiator and its dosage. It achieves lightweight preparation of piezoelectric ceramics, offering significant advantages in the field of energy harvesting and possessing significant application and theoretical value.

The invention relates to the technical field of electrochemical sensing, in particular to a platinum-cobalt hydroxide composite material with cobalt vacancy and a preparation method and application thereof. The platinum-cobalt hydroxide composite material with the cobalt vacancies comprises foamed nickel, Pt nanoparticles and cobalt hydroxide, the cobalt hydroxide is deposited on the foamed nickel, the Pt nanoparticles are deposited on the surface of the cobalt hydroxide, and the cobalt vacancies exist in cobalt hydroxide crystal lattices. Wherein the internal electronic structure of the platinum-cobalt hydroxide composite material is changed due to the existence of the cobalt vacancy, the electron transfer rate in the platinum-cobalt hydroxide composite material is increased, and the regulation and control effect of the cobalt vacancy on the electronic structure and the synergistic catalytic effect of a platinum-cobalt hydroxide heterogeneous interface are utilized. When the platinum-cobalt hydroxide composite material with the cobalt vacancy is used as an ammonia nitrogen electrochemical detection sensitive electrode, the catalytic activity of ammoxidation reaction can be remarkably improved, so that a sensor is endowed with the detection performance of low detection limit, high sensitivity, excellent selectivity and good recovery rate.

This invention discloses a Pt / CoMn2O4 / Na2S2O8 catalyst, its preparation method, and its application, belonging to the field of catalysis technology. The preparation method includes the following steps: S1. Adding a dispersant and a free radical scavenger to a soluble platinum source aqueous solution, degassing, and then... 60 S2. Pt nanoparticles are obtained by irradiation reduction under Co-γ rays; S3. The Pt nanoparticles are mixed evenly with a CoMn2O4 aqueous dispersion to allow surface deposition, and then dried to obtain Pt / CoMn2O4; S4. Na2S2O8 is added to the Pt / CoMn2O4 aqueous dispersion and mixed evenly to allow Na2S2O8 to deposit on the Pt / CoMn2O4 surface, and then dried to obtain the Pt / CoMn2O4 / Na2S2O8 catalyst. This invention reduces the band gap of the Pt / CoMn2O4 catalyst by adding Na2S2O8, increasing the sulfate and hydroxyl radicals on the catalyst surface, causing changes in the valence states of Co and Mn elements in CoMn2O4, and generating more Mn. 2+ / Mn 3+ / Mn 4+ Ion pairs with Co 2+ / Co 3+ The ion pairs are increased, and the number of oxygen vacancies and active sites in CoMn2O4 are increased, thereby enhancing the catalytic performance of the catalyst.

The invention belongs to the field of environment detection, and particularly relates to application of bimetal Pt / Co nano-enzyme to instant portable detection of malathion. The bimetallic Pt / Co nano-enzyme for malathion detection is ZIF-67NF loaded with Pt nanoparticles and has peroxidase activity, nucleotide can enhance the peroxidase activity of the bimetallic Pt / Co nano-enzyme under an alkaline condition, a colorimetric reaction is started by combining the inhibition effect of malathion on alkaline phosphatase and the decomposition effect of the alkaline phosphatase on the nucleotide, and the sensitivity of malathion detection is improved. The method is used for detecting malathion, has the advantages of low detection cost, instantaneity, accuracy and the like, and provides a new method for detecting malathion.

A micro-flower-like manganese cobalt oxide composite catalyst, Pt@δ-MnO2@MnCo2O4, is disclosed. The spinel-structured transition metal oxide MnCo2O4 exhibits a micro-flower-like morphology with "petals" of 10 nm–15 nm thickness, uniform distribution, and a flower diameter of 1.5 μm–2 μm. This micro-flower morphology possesses abundant porosity, providing a large specific surface area and numerous contact sites. δ-MnO2 particles, consisting of plate-like microspheres, are aggregated on the surface of the MnCo2O4 micro-flowers, with a diameter of 90 nm–120 nm. Pt nanoparticles, consisting of fine particles, are uniformly loaded on the surface of the MnCo2O4 micro-flowers, with a diameter of 1 nm–2 nm. The surface of this micro-flower-like manganese cobalt oxide composite catalyst is rough, and a heterojunction is formed between δ-MnO2 and MnCo2O4. The preparation method of the Pt@δ-MnO2@MnCo2O4 microflora-like manganese cobalt oxide composite catalyst is simple. First, a MnCo2O4 support with a microflora-like morphology is synthesized via a solvothermal method and heat treatment. Then, δ-MnO2 and Pt nanoparticles are loaded onto it via a deposition-precipitation method and in-situ reduction method to prepare the Pt@δ-MnO2@MnCo2O4 microflora-like composite catalyst. The prepared microflora-like manganese cobalt oxide composite catalyst exhibits high stability and catalytic activity, and can significantly catalyze the oxidative degradation of formaldehyde and benzene series compounds such as toluene at room temperature.

A UiO-66-NH2 / Pt / UiO-66-NH2 catalyst, its preparation, and its application belong to the field of photocatalytic reduction of CO2. It has a "sandwich" structure: defective UiO-66-NH2 serves as the active component substrate, with a noble metal interlayer of Pt acting as the photocatalytic active center, and UiO-66-NH2 as the outer layer. Pt nanoparticles act as electron mediators, thereby efficiently improving photocatalytic activity. The close contact between the highly dispersed Pt and UiO-66-NH2 shortens the electron transport distance and promotes interfacial charge transfer. Furthermore, UiO-66-NH2 not only inhibits Pt aggregation and leaching but also provides more active sites for the reaction, enabling the material to exhibit excellent activity and stability in CO2 reduction under visible light.

The application relates to a high-efficiency carrier separation photocatalyst based on a metal organic framework material and a preparation method, and belongs to the technical field of photocatalysts. The structure of the high-efficiency carrier separation photocatalyst comprises an octahedral nanocrystal of NH2-UiO-66 loaded with Pt nanoparticles (Pt@NH2-UiO-66) and a two-dimensional Cu-TCPP MOF layer grown in situ on the surface of the Pt@NH2-UiO-66, and finally forms a ternary composite structure of Pt@NH2-UiO-66@Cu-TCPP MOF. Firstly, the Pt nanoparticles with good conductivity are loaded in the NH2-UiO-66, so that the Pt nanoparticles can efficiently enrich CO2 while loading the reaction active center; subsequently, the super-thin two-dimensional Cu-TCPP MOF is grown in situ on the outside of the Pt@NH2-UiO-66 to construct a heterojunction structure, the efficient separation of photo-generated electrons and holes is realized, and the photocatalytic CO2 reduction efficiency is effectively improved.

The invention relates to a Pt-coated UIO-66-CF3-coated TpPa core-shell heterostructure material with photocatalytic performance. The Pt-coated UIO-66-CF3 core-shell heterostructure material is characterized in that Pt nanoparticles are wrapped in UIO-66-CF3 to form a Pt-coated UIO-66-CF3 core-shell structure; and a TpPa material is introduced into the surface of the Pt-coated UIO-66-CF3 core-shell structure, so that the Pt-coated UIO-66-CF3-coated TpPa core-shell heterogeneous composite material is formed. The preparation method comprises the following steps: preparing a solution of Pt nanoparticles, preparing a Pt-coated UIO-66-CF3 material in which the Pt nanoparticles are coated, and synthesizing the Pt-coated UIO-66-CF3-coated TpPa core-shell heterojunction material. The material can be used for photocatalytic decomposition of deionized water to generate hydrogen. According to the invention, Pt nanoparticles are introduced into UIO-66-CF3, and a CF3 group has a regulation effect on Pt, so that the specific surface area electron transfer efficiency of a catalyst material and the electron state density around active sites can be effectively improved, the utilization rate of carriers is fully improved, and the efficiency of photocatalytic hydrogen production is improved; the photocatalytic water production hydrogen production performance is excellent, and the good chemical stability is achieved.

According to the preparation and the application of the Pt1% / SiO2 catalyst, Pt nano particles are loaded on a SiO2 carrier, so that not only can the porous structure and the stability of SiO2 be utilized, but also the catalytic performance of the whole catalyst can be improved by virtue of the high activity of Pt. The addition of the Pt nanoparticles provides additional active sites for SiO2, and the active sites can effectively adsorb and activate reactant molecules, so that the activity of the catalyst is improved. Meanwhile, by optimizing the loading capacity and dispersity of Pt, the performance of the catalyst can be further improved, the dosage of Pt is reduced, and the cost is reduced. In addition, the porous structure of SiO2 is beneficial to uniform dispersion of Pt nanoparticles and prevents agglomeration of the Pt nanoparticles, so that the stability and activity of the catalyst are further improved.

The invention discloses an electrochemical grid-control high-flux in-situ titration method based on a metal-semiconductor Schottky barrier and application of the electrochemical grid-control high-flux in-situ titration method in analysis of electrocatalytic active intermediates. A Pt array is constructed on TiO2, and an external potential is applied to regulate and control a Schottky barrier, so that reversible switching of the conductivity of the substrate is realized, and spontaneous positive feedback current generated by a traditional SI-SECM on the conductive large substrate is effectively inhibited, thereby realizing high-flux and high-resolution quantitative detection of an active intermediate. Experiments and theoretical researches show that the size of the Pt nanoparticles and the potential of the substrate jointly regulate and control the * H coverage and dynamic behavior, and a small-size Pt cluster has an upward moving d-band center, stronger interface charge rearrangement and a lower hydrogen generation energy barrier, so that faster * H dynamics is shown. The calculation of UPS, Mott-Schottky, EIS and DFT proves that the Pt-TiO2 interface forms an adjustable Schottky barrier and enhances charge transfer. The method provided by the invention provides an efficient and reliable analysis platform for structure-activity relationship research in electro-catalytic reaction, and has wide application potential.

The application belongs to the technical field of hydrogen production catalysts for water electrolysis, and particularly relates to a two-dimensional covalent organic framework material loaded with Pt nanoparticles and a preparation method thereof. The two-dimensional covalent organic framework material loaded with Pt nanoparticles has a two-dimensional covalent organic framework containing hexaazatriphenylene (HATN) and Pt loaded on the two-dimensional covalent organic framework in the form of nanoparticles by complexing sites on the nitrogen atoms in HATN. The application successfully constructs the two-dimensional covalent organic framework material loaded with Pt nanoparticles by means of the complexing ability of the HATN structure to metals, and finds that the material can be used as a high-efficiency hydrogen production catalyst for water electrolysis. The material preparation process of the application is simple, and the process does not involve high temperature, and the material has the characteristics of green environmental protection, low preparation cost and large-scale promotion.

The invention discloses a gold platinum-vertical graphene electrode and a preparation method and application thereof.The preparation method of the gold platinum-vertical graphene electrode comprises the steps that a vertical graphene nanosheet is formed on a gold platinum-vertical graphene electrode precursor, and the gold platinum-vertical graphene electrode is obtained, the method for obtaining the gold-platinum-vertical graphene electrode precursor comprises the following steps: dropwise adding a mixed solution on the surface of a metal substrate, reducing Au < 3 + > in the mixed solution into Au nanoparticles in situ on the surface of the metal substrate by using a photocatalysis method, reducing Pt < 4 + > in the mixed solution into Pt nanoparticles in situ, and forming a gold-platinum nanoparticle catalyst layer on the surface of the metal substrate to obtain the gold-platinum-vertical graphene electrode precursor. The gold platinum-vertical graphene electrode precursor is obtained. The gold platinum-vertical graphene electrode has the advantages of high sensitivity, low cost and high catalytic activity.

The application discloses a carbon nitride modified halloysite supported nanometal composite catalyst and a preparation method and application thereof, and relates to the technical field of nanometer catalyst preparation. The catalyst is prepared by the following steps: etching modification of halloysite nanotubes by means of a eutectic solvent, then forming a graphite phase carbon nitride nanometer thin layer on the surface of the modified halloysite by means of a gas phase deposition-pyrolysis method to obtain a carbon nitride modified halloysite composite; then, depositing Co2(OH)2CO3 precursors on the surface of the carbon nitride modified halloysite by means of a sol-gel method, supporting stannous ions by means of the electrostatic adsorption effect of the hydroxyl groups of the Co2(OH)2CO3 precursors, reducing Pt metal ion precursors into Pt nanoparticles by means of the strong reducing property of the stannous ions and realizing a good anchoring effect, and finally forming a stable CoO / Co-Pt / SnO2 composite by means of inert atmosphere calcination, so as to obtain the catalyst. The catalyst has high catalytic activity, selectivity and stability in a selective catalytic hydrogenation reaction, and thus has a good application prospect in the field of nanometer catalysis.

The invention provides an anti-CO poisoning catalyst of a fuel cell, a preparation method of the anti-CO poisoning catalyst and the fuel cell. The anti-CO poisoning catalyst comprises a monatomic catalyst base material and Pt nanoparticles loaded on the surface of the monatomic catalyst base material, the monatomic catalyst base material comprises a nitrogen-doped carbon material and Rh monatomic active sites loaded on the nitrogen-doped carbon material. In the anti-CO poisoning catalyst provided by the invention, when the monatomic catalyst base material is also modified with the S element, the modified S element can enhance regulation and control on the Pt nano-particles and reduce the d band center of Pt, so that the CO adsorption of the Pt nano-particles is weakened, and the CO poisoning resistance is improved; furthermore, the modified S element can also form a synergistic effect with an Rh monatomic active site, so that the CO adsorption of the Pt nano-particles is further reduced, and the CO poisoning resistance is further improved.

The invention relates to a preparation method of a self-driven ultraviolet photoelectric detector based on a ZnO nanorod array, and the method comprises the following steps: growing a ZnO seed layer on a glass substrate with ITO as a bottom electrode, then growing a ZnO nanorod array doped with Mg < 2 + > on the seed layer, and then attaching Pt nanoparticles to the surfaces of nanorods to obtain a Pt-modified ZnO: Mg (at) Pt array; next, NiO is sputtered to the surface of the nanorod, and a ZnO: Mg (at) Pt / NiO core-shell array is obtained after annealing; then uniformly spin-coating PEDOT: PSS on the upper part of the core-shell array, and after the PEDOT: PSS is dried, obtaining a ZnO: Mg (at) Pt / NiO / PEDOT: PSS array; and finally, growing a layer of Ag electrode on the surface of the PEDOT: PSS to obtain the ZnO: Mg (at) Pt / NiO / PEDOT: PSS / Ag ultraviolet photoelectric detector. The ultraviolet photoelectric detector has the advantages of self-driving function, low dark current, high light and dark current ratio and high response speed.

This invention provides a Pt-based molecular sieve templated carbon catalyst, its preparation method, and its application. The catalyst comprises zeolite templated carbon with a three-dimensional porous structure, wherein the pores of the zeolite templated carbon contain Pt nanoparticles and La. 3+ Ions; Pt nanoparticles are confined within the pores. The zeolite template carbon of this invention possesses a uniform pore structure and the three-dimensional continuous porous characteristics of a molecular sieve, replicating the characteristic pore size of a Y molecular sieve. The preparation method of this invention involves modifying the molecular sieve template with La ion exchange, followed by CVD reaction, selective reduction, and alkaline etching, precisely replicating the characteristic pore size of a Y molecular sieve without LaF3 precipitation or significant carbon deposition. This invention also provides the application of the above-mentioned Pt-based molecular sieve template carbon catalyst in catalytically improving the kinetics of the cathode oxygen reduction reaction. It can be combined with S-1 molecular sieves to construct highly efficient oxygen transport channels, showing great application potential in fuel cells and metal-air batteries.

The invention provides a multi-metal nano-enzyme as well as a preparation method and application thereof, and belongs to the field of nano-enzyme materials. The preparation method of the multi-metal nano-enzyme comprises the steps that a chloroauric acid solution and a sodium citrate solution are mixed for a first reduction reaction, and gold nanoparticles are obtained; dispersing the gold nanoparticles, mixing the dispersed gold nanoparticles with a chloroplatinic acid solution and an L-ascorbic acid solution, and carrying out a second reduction reaction to obtain Au / Pt nanoparticles; and mixing the Au / Pt nano particles, L-ascorbic acid, potassium bromide, polyvinylpyrrolidone and ethylene glycol for pretreatment, and then adding an ethylene glycol solution of a sodium hexachloroiridate (III) hydrate for a third reduction reaction to obtain the multi-metal nano enzyme. The multi-metal nano-enzyme prepared by the preparation method provided by the invention has high substrate affinity, catalytic performance and stability, and the multi-metal nano-enzyme has high detection sensitivity and stability on tumor markers when being used for lateral flow chromatography test strips.

The invention provides an ORR catalyst of a fuel cell, a preparation method of the ORR catalyst, a membrane electrode and the fuel cell. The ORR catalyst comprises a carbon carrier and a platinum-based catalyst loaded on the carbon carrier, the ORR catalyst further comprises a doping element Ga doped in the platinum-based catalyst and a doping element N doped on the surface of the carbon carrier. In the ORR catalyst of the fuel cell provided by the invention, the performance of the ORR catalyst is greatly improved through the synergistic doping effect of the doping element Ga and the doping element N; on one hand, the doping element N doped on the surface of the carbon carrier can restrain the agglomeration effect of Pt nano-particles in the heat treatment platinum loading process, the particle size of the particles is reduced, and the dispersity is improved; on the other hand, the catalytic activity of the ORR catalyst is enhanced through the p-d conjugation effect of the doped elements Ga and Pt; on the other hand, the doped element Ga can adjust the electronegativity of the ORR catalyst, and the stability of the ORR catalyst is improved.

The application aims to provide a method for preparing a Pt nanoparticle-Mo2C supported Pt single-atom electrocatalyst through carbon nanocage ortho birestricted pyrolysis path and application thereof, and belongs to the technical field of electrocatalysis.The method is prepared through a one-step double-restriction pyrolysis strategy.Under the spatial restriction of carbon nanocage, Pt single atoms are precisely restricted by Mo2C, and Pt nanoparticles are stably distributed in the vicinity of the Pt single atoms restricted by Mo2C, forming a nanoparticle-single atom ortho biregion synergistic catalytic structure.The design not only adsorbs OH and H intermediates on different sites, breaking through the linear scale limitation of a single site, but also effectively promotes the desorption and overflow of OH by introducing Mo2C as an "OH relay rod", overcoming the problems of OH blockage and slow kinetics in traditional nanometer metal particle and single-atom catalysts.

The application discloses an Au@Pt core-shell structure supported catalyst, which comprises a carrier and Au@Pt nanoparticles supported on the carrier, the Au@Pt nanoparticles are in a core-shell structure, wherein the core layer is Au, the shell layer is Pt, the particle size of the Au@Pt nanoparticles is 2-10 nm, the diameter of the core layer is 1-3 nm, and the thickness of the shell layer is 1-7 nm. The application further discloses a preparation method of the Au@Pt core-shell structure supported catalyst and application of the catalyst in an alcohol oxidation process. According to the method, the alcohol oxidation catalyst can be prepared only through room-temperature liquid-phase reduction, the process is simple and convenient, the prepared catalyst has a unique core-shell structure, and the catalyst has excellent catalytic activity and stability, so that the reaction system can realize high conversion rate oxidation of alcohol to obtain corresponding carboxylic acid without adding an external alkali.