17 results about "Platinum based catalysts" patented technology

This invention discloses a platinum-based catalyst for the hydrogenation reaction, its preparation method, and an electrode. The catalyst uses orthorhombic niobium pentoxide (T-Nb₂O₅) as a support to support the active component platinum. The support is resistant to strong acids and electrochemical corrosion at potentials above 1.0 V (vs RHE). The catalyst exhibits a hydrogenation reaction current density of not less than 200 mA·cm⁻¹ at 0.45 V (vs RHE). ‑2 In preparation, ammonium niobate oxalate hydrate was used as the niobium source, and the mixture was gelled via a sol-gel method. The gel was then heat-treated at 600-700℃ to obtain an orthorhombic niobium pentoxide support. The pH was adjusted to less than 3, and platinum was reduced with sodium borohydride to prepare the catalyst. This catalyst was then used to fabricate a hydrogen depolarization anolyte gas diffusion electrode with a platinum loading of 0.5-1.0 mg·cm³. ‑2 It can operate continuously and stably for no less than 120 hours with a cell voltage in the range of 1.25-1.45V. The catalyst of this invention has high activity and excellent stability, and can be used as a hydrogen depolarization anode in hydrometallurgy, significantly reducing electrolysis energy consumption and making it suitable for industrial applications.

The application discloses a cobalt silicate modified platinum-based catalyst, a preparation method and application, and belongs to the technical field of industrial catalysts. The platinum-based catalyst comprises a carrier, a cobalt silicate modification layer generated in situ on the carrier, and platinum nanoparticles loaded on the cobalt silicate modification layer; the cobalt silicate modification layer is a continuous fibrous structure and is covalently combined with the carrier through Si-O-Co bonds. The cobalt silicate modification layer realizes anchoring and electron transfer of the platinum nanoparticles, makes the platinum in an electron-rich state, weakens adsorption on an alpha, beta-unsaturated aldehyde C=C bond, and strengthens selective adsorption on a C=O bond; when the catalyst is applied to selective hydrogenation of alpha, beta-unsaturated aldehydes, the conversion rate of cinnamyl aldehyde can reach 98.2%, the selectivity of cinnamyl alcohol can reach 92.0%, and the catalyst is suitable for hydrogenation of various alpha, beta-unsaturated aldehydes such as aromatic aldehydes, aliphatic aldehydes and furan aldehydes, and has excellent catalytic activity, selectivity and stability, and good industrial application prospect.

The application belongs to the technical field of catalysts, and provides a one-dimensional platinum-based catalyst, a preparation method and application thereof. The one-dimensional platinum-based catalyst has a nanorod structure and is a platinum-tellurium-bismuth catalyst or a bismuth-doped platinum-tellurium catalyst. The preparation method comprises the following steps: (1) in the presence of a dispersing agent, performing a hydrothermal reaction on a platinum precursor, a tellurium precursor, a bismuth precursor and ascorbic acid in an aqueous solvent to form a platinum-tellurium-bismuth ternary heterogeneous phase alloy; (2) loading the platinum-tellurium-bismuth ternary heterogeneous phase alloy on a carbon material to obtain a platinum-tellurium-bismuth catalyst; optionally, the method further comprises the following step: (3) performing acid treatment on the platinum-tellurium-bismuth catalyst obtained in step (2) to dealloy, thereby obtaining a bismuth-doped platinum-tellurium catalyst. The catalyst exhibits excellent electrocatalytic activity and stability in a formic acid oxidation reaction.

This invention relates to a platinum-based catalyst for the preferential oxidation of CO in a hydrogen-rich atmosphere, its preparation method, and its applications. The method, starting from an interface design perspective, employs a series of synergistic and innovative preparation steps: "selective adsorption with non-polar solvents + controlled pH in-situ anchored hydrolysis + two-step thermal treatment." This successfully solves the technical challenge of traditional methods in constructing a tight, stable, and efficient interface between platinum clusters and iron oxides. The catalyst prepared by this method exhibits high catalytic activity, excellent selectivity, and stability in the preferential oxidation of CO in a hydrogen-rich atmosphere, demonstrating outstanding technological innovation and application value.

The application discloses a kind of anti-sulfur water Pt-based bimetallic CO oxidation catalyst and preparation method thereof, belong to environmental catalytic material technical field.The catalyst prepared by the application uses titanium dioxide as carrier, and adopts impregnation method to load noble metal platinum and adjuvant molybdenum to form bimetallic active component.The catalyst utilizes the regulation effect of Mo species to Pt electronic structure and the competitive adsorption mechanism of sulfur species, effectively solves the problem that traditional single platinum-based catalyst is easily poisoned and inactivated under sulfur-containing and water-containing conditions.Experiments show that the catalyst can still maintain very high CO conversion rate for a long time under harsh working conditions containing high concentration of sulfur dioxide and water vapor, and has excellent anti-sulfur regeneration performance.The catalyst preparation process is simple, and the stability is good, which is suitable for efficient elimination of carbon monoxide in industrial waste gas and motor vehicle exhaust.

The application discloses a kind of ternary platinum-based catalyst of zinc silicate interface stability, preparation method and application, it is characterized in that, catalyst is PtSnZn / SiO2, Zn loading average 1.28wt%-1.30wt%, Sn loading average 0.24wt%-0.26wt%;Pt average loading 0.85wt%.Step: S1, 1) take nano SiO2 dispersed in deionized water;2) add Zn (NO3) 26H2O and SnCl2, stir;3) ultrasonic;4) drying, obtain intermediate SnZn / SiO2;S2, 1) take SnZn / SiO2, add platinum acetylacetone;2) ball milling;3) obtain powder;S3, 1) the powder is placed into tube furnace;2) high-purity argon is imported;3) temperature is raised;4) cooling to room temperature, obtain PtSnZn / SiO2.Application in propane or ethane dehydrogenation reaction can effectively reduce carbon deposition.

This invention discloses a method for on / off modulation of the hydrogen evolution reaction (HER) by defect-induced ferroelectric-antiferroelectric transition in graphene and its application. The method constructs a bilayer system of defective graphene (D-graphene) containing g-C₃N₄-like vacancy pores and g-C₃N₄ layers, with the layers coupled by van der Waals forces. A reversible ferroelectric-antiferroelectric phase transition is achieved through interlayer slip, and the HER is precisely modulated using changes in polarization intensity and direction. The defective graphene bilayer can form an ON-OFF ferroelectric switch, with the Gibbs free energy ΔG for ferroelectric hydrogen adsorption. H * Approaching the optimal value, the catalysis is in the on state; however, excessive hydrogen adsorption in the antiferroelectric state leads to catalysis shutdown. The g-C₃N₄ bilayer can achieve three-level regulation (ON-OFF-ON) through ferroelectric-paraelectric-ferroelectric polarization switching, with the ferroelectric polarization state significantly enhancing HER activity. This invention is free of precious metals, has a low interlayer sliding barrier, and exhibits catalytic performance comparable to platinum-based catalysts. It provides a new strategy for the design of highly efficient intelligent electrocatalysts and novel catalytic switching devices, and has significant application value in the field of clean energy.

The application relates to the technical field of silicone sealing materials, and particularly discloses a single-component UV rapid curing silicone gasket adhesive and a preparation method thereof. The gasket adhesive contains, in parts by mass, 50-70 parts of end-vinyl polydimethylsiloxane, 10-20 parts of hydrogen-containing silicone oil, 3-8 parts of vinyl MQ silicone resin, 5-15 parts of low-viscosity vinyl silicone oil, 8-15 parts of hydrophobic fumed white carbon black, 0.8-1.5 parts of a photoinitiator, 0.02-0.1 parts of a platinum-based catalyst, 0.5-1.5 parts of a silane coupling agent, 0.02-0.1 parts of an alkyne alcohol inhibitor and 0.1-0.5 parts of a functional additive. The low-viscosity vinyl silicone oil has a viscosity of 50-100 mPa.s at 25 DEG C, and a vinyl content of 0.2-0.5 mmol / g. The gasket adhesive has the advantages of stable storage for more than 6 months under the condition of light avoidance at-10 DEG C to 5 DEG C, UV second-level rapid curing, excellent mechanical properties and sealing performance after curing, and can be widely applied to the sealing and gasket forming of electronic appliances, automobile parts, household appliances and the like.

This invention relates to the field of modified polyether technology and provides a method for preparing silane-terminated polyethers. The method involves mixing polyether, alkali metal alkoxide, inorganic catalyst, a first catalyst promoter, and 3-halopropylene for an allylation reaction to obtain a crude allyl polyether product. The crude allyl polyether product is then desalted and washed to obtain an allyl polyether. Finally, the allyl polyether, a platinum-based catalyst, a second catalyst promoter, and silane are mixed for a silanization reaction to obtain the silane-terminated polyether. This invention uses polyether as a base material and improves the traditional allyl-hydrosilylation method to prepare silane-terminated polyether resins. The silane-terminated polyethers prepared by this invention have a silane functionality >1.75 and a viscosity of 4.5~30 Pa·s, exhibiting wide applicability and meeting the application needs of various fields such as building materials and the automotive industry.

A catalyst slurry for fuel cells, its preparation, and its application belong to the field of proton exchange membrane fuel cell technology. The catalyst slurry comprises: molecular carbon electronic materials, a platinum-based catalyst, a perfluorosulfonic acid ionomer, water, and an alcohol solvent. The molecular carbon electronic material forms a permeable interfacial layer on the surface of the platinum-based catalyst nanoparticles. On the one hand, it acts as an electron buffer to regulate the electronic structure of platinum active sites to optimize the adsorption of oxygen reduction intermediates; on the other hand, it acts as a geometric shielding layer to weaken the adsorption poisoning of the platinum surface by the ionomer sulfonic acid groups and reduce interfacial oxygen transport resistance. Thus, it simultaneously improves the activity, durability, and mass transfer performance of the membrane electrode assembly without hindering gas diffusion. The molecular carbon-co-platinum-based catalyst of this invention can be used to prepare cathode catalyst layers, membrane electrode assemblies, and fuel cell stacks, showing promising application prospects of reducing the amount of precious metals used and achieving high power density and long-life operation.

A hydrogen evolution catalyst for acidic seawater electrolysis based on a platinum-cobalt alloy / carbon nanotube composite structure and its preparation method are disclosed, belonging to the field of nanomaterials and catalysis technology. The catalyst consists of a platinum-cobalt alloy / carbon nanotube composite layer supported on a porous conductive substrate, with a platinum-cobalt metal solid solution uniformly anchored on the surface of acidified carbon nanotubes. The method involves mixing platinum acetylacetonate, cobalt acetylacetonate, and acidified carbon nanotubes, followed by solvent-free microwave pyrolysis under an argon atmosphere to obtain a platinum-cobalt alloy / carbon nanotube composite powder in one step. This powder is then drop-coated onto a porous conductive substrate and electrochemically activated to obtain an integral composite electrode catalyst. This invention enables precise control of the catalyst structure and composition; it features low noble metal loading, a simple and environmentally friendly preparation process; and effectively overcomes the problems of easy deactivation and insufficient stability of traditional platinum-based catalysts in acidic media. It exhibits excellent hydrogen evolution activity and long-term stability under high-temperature, high-current-density electrolysis conditions in acidic seawater.

This invention discloses a layered mesoporous carbon support and a platinum-based catalyst, as well as their preparation methods and applications, belonging to the field of electrocatalysis and fuel cell technology. The support possesses a unique two-dimensional layered morphology and a uniformly sized mesoporous network, with nitrogen-doped functional groups on its surface. The average pore size is 2-10 nm, and the BET specific surface area is 500-2000 m². 2 / g. The preparation method includes: mixing a carbon source, a structure-directing agent, and a layered regulator in an alcohol-water solution; inducing self-assembly through solvent evaporation to form a layered precursor gel; and then obtaining the support through stepwise carbonization. High-performance platinum-based catalysts can be prepared by loading platinum nanoparticles onto the above support. This support structure effectively improves mass transfer and conductivity, enhances the interaction with active components, and solves the problems of easy corrosion and platinum particle agglomeration in traditional catalyst supports. The catalyst prepared from it exhibits excellent activity and stability in the oxygen reduction reaction at the cathode of a proton exchange membrane fuel cell.

A method for producing an organopolysiloxane having at least one silicon atom-bonded alkoxysilylalkyl group per molecule is provided. The method comprises the following steps: (i) treating an organopolysiloxane having at least one silicon atom-bonded hydrogen atom per molecule with an alkali salt of carboxylic acid; (ii) removing the alkali salt from the organopolysiloxane; and (iii) reacting the organopolysiloxane with an alkenyl group-containing alkoxysilane in the presence of a platinum-based catalyst. The organopolysiloxane is generally obtained by the method without hydrolyzing any alkoxysilylalkyl groups, and is useful as a surface modifier for various types of fillers.

This application relates to a composite-doped platinum-based catalyst for reducing CO in cigarette smoke, its preparation method, and its application. The preparation method of the composite-doped platinum-based catalyst for reducing CO in cigarette smoke includes: mixing H₂PtCl₆·6H₂O, melamine, and glyoxal in a solvent, heating and stirring to polymerize the precursor, then evaporating the solvent to obtain a polymerized precursor; pyrolyzing the polymerized precursor to obtain a carbon-doped nitrogen material, ball-milling and sieving it, and then mixing it with graphene oxide to obtain the composite-doped platinum-based catalyst. The technical solution of this application can achieve synergistic effects between the platinum-based active component, the carbon-doped nitrogen material, and graphene oxide, constructing a catalytic structure with high specific surface area and abundant active sites.

This invention provides a method for preparing a highly dispersed Pt-based catalyst and its application in VOCs removal, belonging to the field of catalyst technology. The catalyst preparation method includes the following steps: dissolving copper salt and tin salt in dilute nitric acid solution to obtain solution A; adding an aqueous solution of chloroplatinic acid to solution A under stirring to obtain solution B; mixing solution B with titanium oxide uniformly, then drying and calcining to obtain solid A; reducing solid A under a hydrogen atmosphere to obtain the highly dispersed Pt-based catalyst. The Pt loading of the catalyst of this invention is as low as 0.01~0.04 wt% of titanium dioxide, which is an order of magnitude lower than that of ordinary platinum-based catalysts, and both exhibit excellent catalytic activity and stability. The catalyst provided by this invention has excellent low-temperature catalytic oxidation activity and stability for chlorobenzene.

The present application relates to the technical field of propane dehydrogenation catalyst, and discloses a platinum-tin-rare earth molecular sieve catalyst and a preparation method and application thereof.The preparation method is as follows: a silicon source, a template agent, deionized water, a complex, a platinum source, a tin source and a rare earth source are stirred and uniformly mixed to obtain a mixture; the mixture is transferred to a closed reaction kettle for hydrothermal crystallization; and after the crystallization is completed, the product is washed, dried and calcined to obtain the platinum-tin-rare earth molecular sieve catalyst.In the synthesis process of the silicon oxide molecular sieve, platinum, tin and rare earth metals are introduced in situ, the electronic modification and geometric anchoring effect of the rare earth metals on platinum are utilized, and the carbon deposition resistance and thermal stability of the platinum-based catalyst are significantly improved.The catalyst shows better single-pass life and propylene selectivity than the industrial platinum-tin catalyst in the propane dehydrogenation reaction, and has good industrial application prospect.

This invention discloses a carbon-supported platinum-based catalyst PtV, its preparation method, and its application. 5-30 mg of Pt(acac)₂, 2-20 mg of V(acac)₃, 50-300 mg of CTAB, and 2-30 mg of Ketjenblack are placed in a 30 mL beaker, followed by the addition of 5-40 mL of oleylamine. The mixture is stirred until dissolved and homogeneous, then transferred to a 25 mL reactor and heated. The final product is washed with a mixture of cyclohexane and ethanol by centrifugation and calcined in a muffle furnace to obtain the carbon-supported platinum-based catalyst PtV. This invention utilizes the synergistic effect of Pt and V to reduce the d-band center of Pt, while the addition of CTAB and oleylamine modifies the morphology, exposing more active sites. When used as a cathode catalyst in high-temperature proton exchange membrane fuel cells, it exhibits higher power density and stability than commercial 20% Pt / C catalysts. This method is simple, cost-effective, easy to operate, and suitable for large-scale production.