2095 results about "Noble metal" patented technology

The invention discloses a preparation method for selectively oxidizing thioether into sulfoxide through photo-initiation, and belongs to the field of synthesis of medical compounds. The preparation method comprises the following steps that in the air atmosphere, a thioether compound is dissolved in an acetonitrile-water mixed solvent, inorganic metal salt catalysts such as ferric chloride and copper sulfate are added, the mixture reacts for 8-48 h at the temperature of 0-45 DEG C under illumination with the wavelength of 295-405 nm, selective oxidation is carried out, and the sulfoxide product is obtained, and the molar ratio of thioether to the catalysts is 5: 1. The method overcomes the problems of excessive oxidation risk, complicated operation, environmental pollution and the like caused by dependence of a noble metal catalyst and use of a strong oxidant in the existing thioether oxidation method, has the advantages of high catalytic efficiency, high yield and excellent selectivity, can greatly reduce the production cost, is suitable for later industrial synthesis and amplification, and has wide application prospects. The method has the advantages of no expensive metal catalyst or oxidant, simple preparation process, high efficiency, environmental protection, safety and cost saving.

The invention discloses a carbon nitride-based composite material as well as a preparation method and application thereof. The carbon nitride-based composite material comprises a non-metal doped carbon nitride carrier and a noble metal, wherein the noble metal exists in the carrier in an element doping form and / or is loaded on the carrier in an oxide form; the precious metal is one or more of Pt, Pd, Au and Ru, and the nonmetal is one or more of P, S and I. According to the carbon nitride composite material disclosed by the invention, noble metal is utilized to modify carbon nitride, the number of surface active sites is increased, the electron and chemical structures of an active center are adjusted, and meanwhile, generation and migration of photo-generated charges are promoted. Meanwhile, the surface of the carbon nitride composite material is modified by non-metallic elements, so that adsorption and activation of reactant H2O molecules are effectively promoted. The catalyst disclosed by the invention is simple in preparation process, good in repeatability and easy for large-scale production.

The invention relates to the technical field of analysis and detection, in particular to a surface enhanced Raman spectroscopy (SERS)-based nano material detection method, which is characterized in that a heterojunction composite structure consisting of noble metal nano stars and semiconductor oxide nano particles is used as an SERS active substrate; and a specific recognition molecule carrying a Raman reporter molecule is used as a detection probe. During detection, the recognition molecules are firstly combined with the to-be-detected nano material, and then the compound is adsorbed on the surface of the substrate. The tip structure of the noble metal nanostar and a heterojunction interface jointly generate a synergistic effect of electromagnetic enhancement and chemical enhancement, and a reporter molecule signal is doubly amplified, so that high-sensitivity and high-selectivity detection on a to-be-detected nano material is realized. The method solves the problems of weak signal and poor selectivity of the traditional method, and is suitable for rapid and quantitative analysis of trace nano materials in the environment.

The invention discloses a surface oxidation monatomic nano-alloy catalyst as well as a preparation method and application thereof, and belongs to the technical field of advanced nano-energy materials and electro-catalysis. A surface-oxidized monatomic nano-alloy catalyst comprises a hydroxylated carbon nanotube carrier and bimetallic nano-alloy particles loaded on the hydroxylated carbon nanotube carrier, in the bimetallic nano-alloy particles, non-noble metal elements are dispersed in noble metal nano-particles in a monatomic form, the size of the bimetallic nano-alloy particles is 3-4 nm, and the surface-oxidized monatomic nano-alloy catalyst is prepared from a surface-oxidized monatomic nano-alloy catalyst. An oxide layer with the thickness of 0.3-0.6 nm is arranged on the surface of the bimetallic nano-alloy particle; the loading amount of the noble metal is 5-15wt%. Ruthenium and other non-noble metal elements are alloyed and anchored on the carbon material substrate, the conductivity of the catalyst can be greatly improved, the size of alloy particles is accurately controlled within the range of 3-4 nm, active sites can be exposed to the maximum extent, and structural stability is considered.

The invention discloses a coating and a method for recovering precious metals in a physical vapor deposition process. The coating mainly comprises a silver coating positioned on the lower layer and an organic silicon modified layer positioned on the surface of the silver coating. Before precious metal is recycled, the coating is prepared on the surface of the position where precious metal needs to be recycled in the physical vapor deposition process, after physical vapor deposition is completed, an adhesive tape is adopted to be pasted to the surface of the coating, and then the precious metal is stripped from the surface of the coating in a mode of tearing the adhesive tape; or scraping the surface of the coating by adopting a tool, so that the noble metal is stripped from the surface of the coating, and stripped noble metal chips are collected; and finally, the adhesive tape with the precious metal or the collected precious metal scraps are heated, and the precious metal is recycled from a heating product. According to the method, efficient stripping and efficient recycling of the precious metal can be achieved, the coating has no influence on physical vapor deposition equipment and the technological process, and the method is simple in technology, high in operability, environmentally friendly, free of pollution and high in economical efficiency when the precious metal is recycled and can be applied to the recycling process of the precious metal on a large scale.

The invention discloses a supported noble metal catalyst for a wet catalytic oxidation reaction and a preparation process of the supported noble metal catalyst, and belongs to the technical field of catalysts for wastewater treatment. The noble metal catalyst comprises a modified titanium dioxide carrier, transition metal and noble metal, the transition metal and the noble metal are loaded on the modified titanium dioxide carrier, the modified titanium dioxide carrier is modified by adopting rare earth metal, the total loading amount of the noble metal and the transition metal is 0.5-0.7 wt%, and after the titanium dioxide carrier is subjected to rare earth modification, the noble metal and the transition metal are loaded on the modified titanium dioxide carrier. The titanium dioxide carrier transition metal forms stable chemical bonds, precipitation of the transition metal in the use process is reduced, and meanwhile, the transition metal and the noble metal are matched with each other, so that the catalytic activity of the noble metal catalyst is improved.

The invention discloses a dechlorination regeneration method of a chlorine poisoning noble metal catalyst and an application of the regenerated noble metal catalyst in polyolefin hydrogenolysis, and the dechlorination regeneration method comprises the following steps: dispersing the chlorine poisoning noble metal catalyst in water, adding a strong nucleophilic reagent for treatment, and carrying out centrifugal separation, washing and drying treatment to obtain the chlorine poisoning noble metal catalyst. The regenerated noble metal catalyst is obtained. A strong nucleophilic reagent dechlorination regeneration strategy under a room temperature mild condition is provided, chemically inert metal-chlorine bonds are broken through a nucleophilic substitution effect, noble metal particles are prevented from being agglomerated and sintered while deep dechlorination is realized, polyolefin hydrogenolysis activity of the catalyst can be completely recovered, activity improvement can be realized, and the catalyst has a good application prospect. Meanwhile, the regeneration cost is greatly reduced, and the regenerated noble metal catalyst can be used for efficiently hydrogenolyzing, upgrading and recycling waste polyolefin to obtain liquid alkane fuel with high additional value.

The invention discloses a zeolite / silver / copper ternary inorganic nano antibacterial and antiviral material as well as a preparation method and application thereof. The preparation method comprises the following steps: preparing a mixed solution of a template agent and an anchoring agent, loading a metal precursor, adding a silicon source, performing hydrothermal crystallization and performing post-treatment. According to the zeolite / silver / copper ternary inorganic nano antibacterial and antiviral material disclosed by the invention, Ag-Cu bimetallic nanoparticles are formed by introducing copper nitrate and silver together, so that the catalytic activity, selectivity and stability of the zeolite / silver / copper ternary inorganic nano antibacterial and antiviral material are remarkably enhanced, and the dosage of noble metal silver can be reduced.

The invention belongs to the field of hydrogen sensors, and particularly relates to an MEMS hydrogen sensor based on a high-entropy alloy and a preparation method of the MEMS hydrogen sensor. The hydrogen sensor comprises an insulating substrate, an interdigital electrode and a hydrogen sensitive layer, the hydrogen sensitive layer is formed by compounding high-entropy alloy nanoparticles composed of at least five transition metal elements and a semiconductor metal oxide substrate, and the high-entropy alloy nanoparticles are uniformly dispersed on the surface of the semiconductor metal oxide substrate to form a heterojunction; the atomic percent of each transition metal element in the high-entropy alloy nanoparticles is 5%-35%; the semiconductor metal oxide substrate is of a SnO2 or ZnO nano structure, and the specific surface area is larger than or equal to 50 m < 2 > / g. The preparation method is the preparation method of the hydrogen sensor. The hydrogen sensor provided by the invention has an ultralow hydrogen detection limit, the response speed is within a second level, the consumption of noble metal is greatly reduced, and the activity attenuation in a high-temperature environment is small.

The invention discloses a non-noble metal catalyst, a preparation method thereof and application of the non-noble metal catalyst in preparation of acetic acid through methane oxidation, and belongs to the field of direct conversion and utilization of methane. The active metal of the catalyst is transition non-noble metal MnOx, and the carrier is an MFI type molecular sieve (ZSM-5). The catalyst can directly react methane and oxygen at low temperature to prepare acetic acid without adding a co-reducing agent and carbonylation raw materials (such as H2 and CO). The nanometer MnOx catalyst has the advantages of mild reaction conditions, high acetic acid selectivity and the like, the acetic acid selectivity can reach 81.8%, and the nanometer MnOx catalyst shows good recycling stability.

The invention discloses a doped perovskite catalyst with a noble metal exposed on the surface, a preparation method and application thereof, belongs to the technical field of catalytic materials, and particularly relates to application in catalytic removal of volatile organic compounds. The method comprises the following steps: performing composite molding on rare earth elements / alkaline earth metals, transition metals and noble metals by adopting a sol-gel method, and performing strong acid surface etching and other operations. The surface of the catalyst is provided with a noble metal nanocluster or noble metal nanoparticle structure, so that the surface area is increased, more active sites can be provided, the adsorption of reactant molecules is enhanced, and the conversion rate and selectivity of a catalytic reaction are further improved. Based on the structure and performance advantages, the catalyst disclosed by the invention can be used for efficiently removing volatile organic compounds, can effectively reduce the initial temperature of the catalytic oxidation reaction of the volatile organic compounds, and has a wide application prospect in treating various industrial processes needing high-temperature and efficient catalysis.

The invention discloses a copper-based catalyst for catalyzing partial hydrogenation of nitrocyclohexane to prepare cyclohexanone-oxime as well as a preparation method and application of the copper-based catalyst. The catalyst comprises a main active component and an auxiliary active component, the main active component is copper, the auxiliary active component is selected from one or more of titanium, vanadium, chromium, molybdenum, zirconium, cadmium, indium, tin, antimony, niobium, silver, iron, zinc, magnesium, aluminum, bismuth, manganese, lanthanum, gold or lead, the total molar ratio of the copper to the auxiliary active component is (100-1): 1, and the catalyst is prepared by adopting a coprecipitation method or a supported impregnation-coprecipitation method. And the process is simple and green. Under mild conditions, the catalyst can realize the conversion rate gt of nitrocyclohexane; the selectivity of cyclohexanone-oxime is greater than or equal to 99%, and the method is obviously superior to the existing non-noble metal system, and is low in cost, good in stability and suitable for industrial production of green synthesis of caprolactam.

To provide a light-emitting compound having a narrow half-value width and a stable skeleton, for example a novel polycyclic aromatic compound applicable to blue light emission, and to provide a method for producing a light-emitting compound that is capable of producing such a polycyclic aromatic compound, preferably using a non-noble metal catalyst, which is suitable for a sustainable society.SOLUTION: According to one embodiment of the present invention, a light-emitting compound is a polycyclic aromatic compound represented by the following formula (I).SELECTED DRAWING: None

The invention discloses a conjugated polymer photocatalyst, a preparation method thereof and application of the conjugated polymer photocatalyst in photocatalytic synthesis of nitric acid, and belongs to the technical field of polymer materials and photocatalysis. The preparation method of the catalyst mainly comprises the following steps: synthesizing an intermediate 2CzTPN-Br through a nucleophilic substitution reaction, then synthesizing an intermediate TBBA through an esterification reaction, and finally copolymerizing the intermediate 2CzTPN-Br and the intermediate TBBA through a coupling polymerization reaction to obtain the target catalyst. The preparation method disclosed by the invention is controllable in process, and the obtained catalyst does not need to participate in noble metal and has wide light absorption, high specific surface area and excellent carrier separation efficiency; when being applied to photocatalytic synthesis of nitric acid, nitrogen in air can be directly and efficiently converted into nitric acid under the mild conditions of room temperature, air atmosphere and water serving as a solvent, excellent durability is shown, the yield of nitric acid can reach 4466.2 mol g <-1 > cat after 324-hour continuous illumination, and wide application prospects are achieved in the field of green synthesis.

The application provides a continuous hydrogenation-isomerization method capable of meeting the treatment requirements of biological oils, especially waste oils, using a homogeneous hydrogenation process with strong adaptability to raw materials as a raw material pretreatment process, and matching a high-activity nanometer transition metal sulfide catalyst. On this basis, a catalytic distillation process is used for selective cracking of long-chain alkanes to improve the yield of medium and long-chain alkanes; an ultramicro flow hydrogen gas mixer and a reduced non-noble metal hydrogenation-isomerization catalyst are used to reduce the hydrogen / oil ratio and the energy consumption of the circulating hydrogen system, and to reduce the production cost of the catalyst, so as to finally realize efficient and low-carbon conversion of waste oils, and low-cost and high-selectivity preparation of biological aviation kerosene.

The invention discloses a non-noble metal ORR catalyst and a preparation method thereof, and belongs to the technical field of electro-catalysis. The method comprises the following steps: (1) adding 5, 10, 15, 20-tetra (4-cyanophenyl) porphyrin and nickel salt into an organic solvent, and synthesizing a supramolecular crystal precursor UPC-S7 through solvothermal reaction; (2) carbonizing the supramolecular crystal precursor UPC-S7 in an inert atmosphere to obtain a Ni-coated NC material; (3) oxidizing the Ni-coated NC material in an oxygen-containing atmosphere to obtain a Ni / NiO-coated NC material; and (4) sequentially soaking and etching the Ni / NiO-coated NC material by using a nitric acid solution and an ammonia water solution, and then washing and drying to obtain the non-noble metal ORR catalyst. The prepared catalyst does not contain precious metal such as platinum, the raw material cost is remarkably reduced on the basis of ensuring the ORR activity and stability of the catalyst, and a new scheme is provided for solving the cost bottleneck of a fuel cell.

The invention discloses a sulfur-resistant non-noble metal catalyst for removing carbon monoxide and a preparation method thereof. The preparation method comprises the following steps: step 1, dissolving aluminum oxide, cerium-containing metal salt and a precipitator in a solvent, fully mixing, and dispersing to obtain a colloidal dispersion system; a hydrothermal product is obtained after the hydrothermal reaction, and solid powder A is obtained after the hydrothermal product is roasted; step 2, dropwise adding a copper-containing metal salt solution into the solid powder A under a ball-milling condition to obtain a turbid liquid; carrying out heat preservation roasting to obtain solid powder B; 3, roasting the molybdenum-containing metal salt, and performing thermal decomposition to obtain solid powder C; and 4, adding the solid powder C obtained in the step 3 into the turbid liquid of the solid powder B, dispersing, and roasting to obtain the required catalyst. The obtained catalyst is stable in overall structure and can still keep good catalytic performance in a sulfur-containing environment.

The invention provides a nickel metal hydroisomerization catalyst as well as a preparation method and application thereof. The catalyst comprises nickel, an alumina carrier and a molecular sieve, the nickel is loaded on the alumina carrier, and the content of the nickel in the catalyst is 1-10wt%; the molecular sieve is an SAPO molecular sieve. According to the invention, alumina is used as a carrier, non-noble metal nickel is loaded through a wet immersion method and is mixed with the molecular sieve to prepare the alkane isomerization catalyst, so that active metal with smaller particle size and higher dispersity can be provided, metal agglomeration at high temperature is avoided, and the utilization rate of metal is increased; the catalyst with excellent catalytic activity can be obtained only by loading low-content nickel metal, the catalyst has higher catalytic activity and selectivity, the obtained product contains more isomers, and the low-temperature fluidity of the product can be remarkably improved.

The present invention relates to a non-noble metal long-chain alkane dehydrogenation catalyst, which uses CeO2 and a transition metal M as main active components, and the mass percentage of the transition metal M is 0-30 wt%; wherein M is one or a combination of more of Fe, Co and Ni. Meanwhile, the invention also discloses a preparation method and application of the catalyst. The catalyst provided by the invention shows good dehydrogenation activity and stability in an inert atmosphere. An alternative solution which is low in cost, high in performance and easy to operate is provided for a long-chain alkane dehydrogenation process.

The invention provides a treatment method for synergistically enhancing the comprehensive performance of a neodymium-iron-boron magnet, and belongs to the technical field of magnetic materials. According to the method, a heavy rare earth layer and a corrosion-resistant metal layer such as copper, nickel and cobalt for promoting grain boundary diffusion of heavy rare earth are respectively deposited on the surface of the neodymium-iron-boron magnet by adopting a multi-layer electroplating method, the coercivity of the neodymium-iron-boron magnet is enhanced through grain boundary diffusion, and the corrosion resistance of the magnet is enhanced through a nickel-cobalt coating. The treatment method comprises the following steps: carrying out electrochemical deposition on the neodymium-iron-boron magnet in a heavy rare earth metal plating solution, and then respectively electroplating a copper plating layer and a nickel-cobalt plating layer to obtain a heavy rare earth-containing plating layer with strong corrosion resistance and good plating film binding force; the neodymium-iron-boron magnet containing the heavy rare earth coating is subjected to heat treatment, and the coercive force of the magnet is improved through heavy rare earth grain boundary diffusion. The neodymium iron boron grain boundary diffusion process and the surface corrosion prevention process are subjected to integrated treatment, the technological process of high-performance neodymium iron boron industrial preparation is shortened, and the coercive force and the corrosion resistance of the magnet are comprehensively enhanced.

The invention provides an alkaline hydrogen evolution electrocatalyst and a preparation method and application thereof.The alkaline hydrogen evolution electrocatalyst comprises a carrier and an active component, the carrier comprises a reduced graphene oxide layer and a rare earth element doped transition metal oxide layer which are sequentially stacked, and the active component comprises precious metal; the active component is loaded on the surface of one side, far away from the reduced graphene oxide layer, of the rare earth element doped transition metal oxide layer. According to the alkaline hydrogen evolution electrocatalyst provided by the invention, the transition metal oxide layer doped with the noble metal and the rare earth element can form a synergistic catalysis interface, and the reduced graphene oxide layer is used as a carrier substrate, so that a continuous conductive network can be constructed to guarantee electron transmission, and a loaded material can be dispersed and supported through a lamellar structure of the reduced graphene oxide layer; through the synergistic effect of the components and the structure, the hydrogen evolution reaction activity and stability of the catalyst under the alkaline condition are remarkably improved.

The invention discloses a high-stability ammonia decomposition hydrogen production catalyst as well as a preparation method and application thereof, and belongs to the technical field of new energy hydrogen storage and ammonia hydrogen energy storage. The high-stability catalyst for hydrogen production through ammonia decomposition comprises an active component, an auxiliary agent and a carrier, the active component is RuOx, x is equal to 2-3, and the mass of the active component accounts for 0.5-10% of the mass of the high-stability catalyst for hydrogen production through ammonia decomposition; the auxiliary agent comprises one or more of CaOy, MgOy, BaOy and SrOy, y is equal to 1-2, and the mass of the auxiliary agent accounts for 1-10% of the mass of the high-stability catalyst for hydrogen production through ammonia decomposition; the carrier comprises one or more of mesoporous SiO2, mesoporous Al2O3, mesoporous TiO2 and mesoporous ZrO2, and accounts for 85-98.5% of the mass of the high-stability catalyst for hydrogen production by ammonia decomposition. The invention provides an ammonia decomposition hydrogen production catalyst which is excellent in thermal stability and high in precious metal Ru utilization rate.

The invention belongs to the field of petrochemical engineering, and discloses a bimetallic Ni-Pt / RFE hydroisomerization catalyst and a preparation method and application thereof. The preparation method comprises the following steps: dissolving a nickel precursor in water, stirring until clarification, and dropwise adding ammonia water to obtain a mixed solution 1; rFE is added into the mixed solution 1, the pH value is adjusted to be 9-11.5, suction filtration, washing and drying are conducted after stirring, and Ni / RFE is obtained; dissolving a platinum precursor in water, stirring until the solution is clear, and dropwise adding ammonia water to obtain a mixed solution 2; and adding the Ni / RFE into the mixed solution 2, adjusting the pH value to 9-11.5, stirring, and carrying out suction filtration, washing, drying and roasting to obtain the Ni-Pt / RFE. The method is simple and convenient to operate and mild in condition, the catalyst activity and the isomerization efficiency are remarkably improved through the synergistic effect of Ni and Pt, the catalyst preparation cost is greatly reduced while the use amount of precious metal is reduced, efficient conversion of long straight-chain alkane can be achieved, and the isomerization conversion rate of n-dodecane within 60 minutes can reach nearly 90%.

The invention belongs to the field of electrochemical energy storage, and discloses an electrode suitable for an organic flow battery and a preparation method of the electrode. The electrode comprises a porous electrode substrate and an amino functional group loaded on the surface of a pore channel, and the electrode substrate is prepared by taking mixed powder of noble metal, rare earth metal and titanium alloy as a raw material. A selective laser melting process is adopted to prepare a porous electrode substrate, and then an electrostatic self-assembly process is adopted to load amino functional groups on the surfaces of pore channels. The electrode has a porous structure with a high specific surface area, and can provide sufficient reaction sites for electrochemical reaction. Meanwhile, the loaded amino functional group can enhance the activity and stability of positive and negative electrode electrochemical substances. The electrode base material comprises a noble metal with catalytic activity and a rare earth metal, and an active rare earth oxide layer doped with a noble metal oxide can be formed on the surface of the electrode after printing. According to the electrode, the energy efficiency of the organic flow battery can be improved, and the stable cycle index and the service life are prolonged on the basis of maintaining the energy efficiency.

The invention provides a phosphorus-nickel co-doped carbon nitride composite material for photocatalytic-Fenton degradation of pollutants and a preparation method and application thereof, and the preparation method comprises the following steps: in a muffle furnace, heating urea and ammonium dihydrogen phosphate to convert into phosphorus-doped carbon nitride; the preparation method comprises the following steps: dissolving phosphorus-doped carbon nitride in absolute ethyl alcohol, adding an anhydrous nickel chloride aqueous solution, carrying out ultrasonic treatment, drying, placing in a muffle furnace, and carrying out high-temperature heating conversion to obtain the phosphorus-nickel co-doped carbon nitride composite material. According to the metal monatomic catalyst synthesized by adopting a specific preparation method, the yield of photo-generated hydrogen peroxide is selectively improved while separation and transfer of photo-generated carriers are synergistically promoted by two sites; and the iron circulation can be well promoted, so that the photocatalytic-Fenton pollutant degradation effect which is comparable with that of precious metal doping is realized.

The invention provides a preparation method of an omariglitazone intermediate, which comprises the following steps: by taking p-halogenated benzaldehyde as a raw material, carrying out aldol condensation reaction, hydrolysis, decarboxylation, reduction, ring closing and the like to obtain an intermediate as shown in a formula 9, carrying out catalytic reaction, reduction reaction, ring closing and the like to obtain an intermediate as shown in a formula 13, and finally hydrolyzing to obtain a target product omariglitazone intermediate A. According to the invention, links of precious metal use and chiral resolution (key steps influencing cost and yield) in the prior art are avoided, and a method for synthesizing a single configuration through a chemical method is adopted, so that the yield is greatly improved, and the production cost is greatly reduced; meanwhile, a synthesis route is broken through, a target product is synthesized through cheap initial materials, and post-treatment is simpler and more controllable.

This invention discloses a photocatalytic negative oxygen ion near-field purification eyeglass component and its preparation method. The component includes an eyeglass substrate (lens or frame). From the inside out, the outer surface of the substrate is sequentially provided with a functional film layer, a plasma activation layer, and an outermost composite film layer of nitrogen-doped anatase titanium dioxide supported on a Pt-Au-Ag-Pd quaternary noble metal. This film is responsive to the entire visible light band from 400nm to 700nm and stably generates ≥1000 negative oxygen ions / cm³ within a 30cm near-field breathing zone of the wearer's mouth and nose under normal lighting conditions. It also achieves antibacterial and bacteriostatic effects, degradation of harmful gases, surface self-cleaning, and anti-fogging functions. This invention optimizes the film structure, allowing the photocatalyst to directly contact air and visible light, maximizing catalytic efficiency. It is also compatible with lenses and frames, integrating multiple effects such as eye protection, purification, antibacterial properties, and anti-fogging. The process is universal and mass-producible.

Herein is described a composite material, the composite material comprising composite 5 particles comprising particles of a mesoporous carbon support material having dispersed on their surfaces noble metal nanoparticles and / or noble metal-M alloy nanoparticles and optionally particles of the elemental metal M or metal oxide MOy, wherein y is >0 to a stoichiometric value of the metal oxide, wherein M is a less noble metal than the noble metal, wherein the composite particles have a BJH average pore diameter of from 2 to 0 50 nm and a particle size D90, as measured by laser diffraction and volume distribution, of 10 µm or less.

The invention relates to the technical field of precious metal recovery and purification, in particular to a metal rhodium recovery and purification method which comprises the following steps: S1, adjusting the pH value of rhodium leaching liquid, heating, adding a reducing agent, and filtering after reaction to obtain primary impurity removal liquid; s2, controlling the pH value of the primary impurity removal liquid to be 1.5-2, heating, adding thiodiglycolic acid and ammonium salt, reacting, and performing solid-liquid separation to obtain primary rhodium-containing precipitate; s3, dispersing the primary rhodium-containing precipitate in an acid solution, adding a strong oxidant, carrying out heating reflux, and adjusting the pH value to 6-7 to obtain a secondary rhodium-containing precipitate; s4, dispersing the secondary rhodium-containing precipitate in a solution with a pH value of 13-14 for pulpifying, adding a reducing agent, carrying out a reduction reaction at 90-100 DEG C, and carrying out solid-liquid separation to obtain a tertiary rhodium-containing precipitate; s5, calcining the third rhodium-containing precipitate, and performing hydrogen reduction to obtain metal rhodium; the method has the advantages that the recovery efficiency of rhodium can be improved, and the pressure on the environment is reduced.

The invention relates to the technical field of catalysts, and provides an anti-poisoning CO oxidation catalyst as well as a preparation method and application thereof. The molecular sieve is used as a carrier, the noble metal is used as an active component, two ion exchange processes of liquid ion exchange and solid ion exchange (roasting) are adopted, the noble metal active component is loaded in a pore channel of the molecular sieve carrier, and the obtained catalyst shows excellent catalytic activity and anti-poisoning tolerance in sintering flue gas CO catalytic oxidation. The prepared catalyst has SO2 resistance, water resistance, HCl resistance and alkali metal poisoning resistance at the same time, is long in service life, high in catalytic activity and high in CO conversion rate, can be applied to treatment of CO in sintering flue gas in the steel industry, can reduce emission of CO, can also utilize the high calorific value characteristic of CO to achieve energy-saving value, and has wide application prospects.