267 results about "Rhodium" patented technology

The invention provides a method for recovering platinum group metal from a waste automobile exhaust purification catalyst, and belongs to the field of precious metal recovery. The method comprises the following steps: carrying out crushing and impurity removal pretreatment on the waste catalyst to obtain solid residues; mixing the obtained solid slag with alkali liquor, and performing hot-pressing activation to obtain active slag; leaching the active slag by using an acid leaching system of hydrochloric acid-hydrogen peroxide-sodium chloride to obtain a leaching solution enriched with platinum group metals; adjusting the acidity of the leachate, adding a first adsorption material, selectively adsorbing platinum and palladium, and separating supernate and a platinum / palladium enrichment material; adjusting the acidity of the supernate, adding a second adsorption material, selectively adsorbing rhodium, carrying out solid-liquid separation, and collecting a rhodium enrichment material; respectively eluting and refining the platinum / palladium enrichment material and the rhodium enrichment material, and recovering platinum, palladium and rhodium; through the optimally designed recovery method of alkaline hot-pressing activation-mild acidic directional leaching-two-stage magnetic adsorption separation, efficient recovery of platinum, palladium and rhodium in the waste automobile exhaust catalyst is realized.

The invention relates to the field of preparation of nano materials, in particular to a preparation method of a metal-oxide cluster electro-catalytic material based on an ammonia-mediated electrostatic adsorption principle, and aims to solve the problem that a metal-oxide cluster heterogeneous interface is difficult to accurately construct by an existing method. The preparation method comprises the following steps: dispersing a carbon carrier, a soluble inorganic compound containing platinum, ruthenium and rhodium, a soluble metal complex anion salt and dopamine hydrochloride in a water-alcohol mixed solution, adding ammonia water, and preparing a metal-oxide heterogeneous cluster precursor through an ammonia-mediated electrostatic adsorption effect; and pyrolyzing the precursor in a reducing atmosphere to prepare the metal-oxide cluster electro-catalytic material. The prepared electro-catalytic material has a definite heterogeneous cluster interface and has excellent performance in alkaline hydroxide reaction. The method is simple and convenient to operate, low in cost and low in energy consumption, can be popularized to various metal-oxide cluster electro-catalytic materials, and has application potential.

The invention provides a method for recovering rhodium in organic residual liquid containing triphenylphosphine / phosphine oxide, and relates to the technical field of precious metal recovery, and the method comprises the following steps: S1, carrying out reduced pressure rectification on the organic residual liquid containing triphenylphosphine / phosphine oxide to remove volatile components until the indexes of the residual liquid meet the feeding requirements of a subsequent process, and collecting light components for independent storage; s2, adding an acidic medium into the organic phase after light component removal, stirring and heating, introducing an oxidizing agent to carry out oxidation-complexation reaction, maintaining reaction conditions until the reaction is complete, standing for phase splitting, and collecting a water phase containing rhodium complex ions; according to the method, a core process combining oxidation-chlorination transfer and anion exchange adsorption is adopted, and key parameters of each process are accurately controlled, so that the rhodium recovery rate is stabilized at 95% or above, the rhodium content in the residual liquid can be reduced to 5 ppm or below, the industrial emission standard is completely met, and compared with the prior art, the resource recovery efficiency is greatly improved, and the cost is reduced. And waste of precious metal resources is effectively reduced.

The invention provides a composite hydrogen transfer catalyst based on an MOFs material as well as a preparation method and application of the composite hydrogen transfer catalyst. The composite hydrogen transfer catalyst comprises the MOFs material loaded with an active metal component and solid alkali, the active metal component is selected from at least one of palladium, platinum, ruthenium, rhodium and nickel; the active metal component accounts for 0.5-5% of the mass of the catalyst; the MOFs material is selected from at least one of ZIF-8, MIL-101, UiO-66, HKUST-1 and MOF-5 (Metal Organic Frameworks); the solid alkali is selected from at least one of magnesium oxide, calcium oxide, hydroxyapatite and barium oxide. The catalyst provided by the invention has the advantages of high catalytic activity, good selectivity, strong stability, reusability and the like, can efficiently catalyze fatty alcohol to perform hydrogen transfer reaction under a lower-temperature reaction condition to prepare Guerbet alcohol, remarkably improves the yield and purity of a product, and reduces the reaction energy consumption and cost.

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.

A hydrometallurgical process for recovering a plurality of metals from a complex rare and precious material, comprising the following steps: step 1: adding a complex rare and precious material to a hydrochloric acid solution, adding an oxidant for reaction, and then performing filtration to obtain a chlorination liquid and a chlorination residue; step 2: using two-stage counter-current gold loading to obtain a gold-loaded liquid and a post-loading liquid, reducing the gold-loaded liquid, performing clarification to obtain an organic phase, and filtering a precipitate to separate a post-reduction liquid and sponge gold; performing evaporation and concentration on the post-reduction liquid to produce a concentrate 1 and a condensate; and cooling and crystallizing the concentrate, performing filtration to obtain residual oxalic acid, and returning the residual oxalic acid to the reduction process and a post-crystallization liquid to gold loading; step 3: performing low-temperature distillation on the post-loading liquid to obtain a concentrate 2; step 4: performing high-temperature distillation on the concentrate 2 to obtain a concentrate 3; step 5: performing directional crystallization and centrifugal filtration on the concentrate 3 to obtain a crystallization residue and selenous acid; and step 6: washing the crystallization residue by using cold water or a low-acid-level condensate produced in step 3, and performing filtration to obtain a tellurium residue and a palladium-platinum-rhodium-rich liquid.

The invention relates to a forming method for composite electroplating of an MEMS (Micro Electro Mechanical System) probe. Structural patterns of a needle tip or / and a needle body are / is photoetched through a micro-electro-mechanical process, the needle tip or / and the needle body is / are formed through electroplating of a composite plating solution after pretreatment, the composite plating solution is obtained by mixing a metal base solution and a turbid liquid, the metal base solution is a nickel base solution and / or a rhodium base solution, and the turbid liquid is a nickel base solution and / or a rhodium base solution. The suspension is formed by suspending nano-powder in water through a dispersing agent. Compared with the prior art, the technology provided by the invention has the following advantages that the MEMS process technology is combined with the composite plating solution to be used for various probe structures, and the performance of the prepared material is greatly improved compared with that of a pure metal coating; the composite plating solution prepared from the plating solution and the second-phase particles is high in stability, and the electroplating process is easy to operate; the nickel-based composite plating solution can be used for obtaining a main body material with higher hardness, better wear resistance and better flexural property; the rhodium-based composite plating solution is used for preparing a needle point material, has higher hardness and wear resistance, and improves the brittle fracture problem.

A process for producing amines by reductive amination, the process includes introducing a feed stream, the feed stream comprising an amino alcohol and a reducing agent, and hydrogen in a reaction zone of a reactor, and contacting the feed stream with a catalyst in the reaction zone. A hydrogen flow rate into the reaction zone is adjusted, and a product stream comprising ethyleneamines is extracted. The catalyst includes a carrier component selected from alumina, silica, and combinations thereof; and an active component having a first metal, a second metal, and a third metal. The first metal is selected from cobalt, nickel, and copper, the second metal is selected from rhenium, ruthenium, chromium, zinc, sodium, calcium, magnesium, strontium, lithium, potassium, barium, cesium, lanthanum, tungsten, iron, silver, titanium, manganese, aluminum, rhodium, platinum, palladium, iridium, and combinations thereof, and the third metal is niobium.

The application discloses a phosphine ligand modified nitrogen-doped graphene oxide / porous carbon supported metal catalyst and a preparation method and application thereof. The catalyst comprises phosphine ligand modified nitrogen-doped graphene oxide / porous carbon and rhodium supported on the nitrogen-doped graphene oxide / porous carbon; and the molar ratio of rhodium to phosphine is 1:1-100 in terms of elements. The phosphine ligand modified nitrogen-doped graphene oxide / porous carbon supported metal catalyst has better catalytic activity and product selectivity.

The present invention discloses an ammonia oxidation process and a method for recovering Rh from a gas phase comprising volatile precious metals, comprising the steps of: a) generating or providing volatile precious metals, particularly by operating a catalytic system comprising a catalyst, wherein the catalyst contains precious metals, wherein the precious metals at least comprise Rh, wherein the volatile precious metals comprise at least volatile Rh; b) contacting volatile Rh generated in step a) with a recovery system comprising a compound of formula Co3-xMxO4, where M is Fe or Al and x = 0-2; and c) forming a solid composition comprising the compound of formula Co3-xMxO4 and Rh, wherein the compound of formula Co3-xMxO4 is bonded with Rh, particularly as determined by SEM-EDS and TEM analysis. The present invention further relates to the use of the compound of formula Co3-xMxO4, where M is Fe or Al and x = 0-2, or the use of the recovery system, for recovering at least volatile Rh.

The invention relates to the field of catalysts. The invention relates to a catalyst for catalytic oxidation of carbon monoxide in industrial sulfur-containing flue gas. A carrier is a cordierite honeycomb ceramic carrier coated with activated aluminum oxide (Al2O3), silicon oxide (SiO2) or titanium oxide (TiO2), or a honeycomb carrier with titanium oxide as a skeleton; the noble metal active component is selected from one or a combination of more of palladium (Pd), platinum (Pt) and rhodium (Rh), the total loading capacity accounts for 0.05-0.4 wt% of the mass of the carrier, and the noble metal component is loaded on the surface layer of the carrier at the depth of 10-300 microns and is of an eggshell type distribution structure; the cocatalyst component is selected from one or a combination of more of vanadium oxide (VO), tungsten oxide (WO), cerium oxide (CeO), molybdenum oxide (MoO) and lanthanum oxide (La2O3) and is uniformly distributed on the carrier. Unification of activity, stability and economical efficiency of the catalyst is achieved, the problems that a catalytic oxidation catalyst is prone to inactivation, low in activity and high in cost in complex sulfur-containing flue gas are solved, and the industrial application value is remarkable.

Exhaust gas purification device (100), comprising: a substrate (10) comprising an upstream end (I) through which an exhaust gas is introduced into the device and a downstream end (J) through which the exhaust gas is discharged from the device, wherein the substrate (10) has a length Ls between the upstream end (I) and the downstream end (J); a first catalyst layer (20) containing palladium particles, which extends over a first region (X) and is in contact with the substrate (10), wherein the first region (X) extends between the upstream end (I) and a first position (P), wherein the first position (P) is located at a first distance La from the upstream end (I) in the direction of the downstream end (J); a second catalyst layer (30) containing rhodium particles, which extends over a second region (Y) and is in contact with the substrate (10), wherein the second region (Y) extends between the downstream end (J) and a second position (Q), the second position (Q) being located at a second distance Lb from the downstream end (J) in the direction of the upstream end (I); and a third catalyst layer (40) containing rhodium particles, which extends over a third region (Z) and is in contact with at least the first catalyst layer (20), wherein the third region (Z) extends between the upstream end (I) and a third position (R), wherein the third position (R) is located at a third distance Lc from the upstream end (I) in the direction of the downstream end (J), wherein a mean particle size distribution of the rhodium particles contained in the second catalyst layer (30) and the third catalyst layer (40) is from 1.0 nm to 2.0 nm, and a standard deviation of the particle size distribution of the rhodium particles contained in the second catalyst layer (30) and the third catalyst layer (40) is 0.8 nm or less.

The invention provides a catalyst for maleic acid water phase hydrogenation as well as a preparation method and application thereof. The catalyst comprises a carrier, an active metal component and a nitrogen-doped carbon layer, wherein the nitrogen-doped carbon layer is formed by shrinking and carbonizing melamine and formaldehyde in pores of the carrier loaded with the active metal component, and the active metal component is coated with the nitrogen-doped carbon layer; the active metal component is selected from at least one of palladium, ruthenium, gold, rhodium and iridium, and the carrier is a spherical or granular porous material. The catalyst disclosed by the invention comprises the nitrogen-doped carbon layer formed by shrinking melamine and formaldehyde in pores of the carrier loaded with the active metal components and carbonizing, so that the active metal components of specific types can be promoted to be uniformly dispersed in the catalyst structure, and the catalytic performance is improved; meanwhile, by combining the effect of the carrier, the mechanical strength of the catalyst is effectively improved, so that the catalyst can still maintain high activity after being used in an acid environment for a long time, and the maleic acid water-phase hydrogenation reaction can be efficiently catalyzed in a long-life manner.

There is provided a method for decreasing leakage of matter from an object to a surrounding, said object being coated with a coating at least partially applied on the object, said coating comprising an at least partially covering layer comprising silver, said object optionally comprising area(s) without said layer, said coating comprising metal particles applied on the layer and optionally on areas without said layer, said metal particles comprising palladium and at least one metal selected from the group consisting of gold, ruthenium, rhodium, osmium, iridium, niobium, neodymium and platinum and wherein the amount of the metal particles is in the interval 0.01-8 μg / cm . Advantages include that leakage of matter such as latex allergens of metal ions can be reduced while the coating is both biocompatible and antimicrobial. Further, the blood clotting can be reduced.

This invention provides a thiourea-tertiary amine bifunctional chitosan microsphere and its preparation method, belonging to the field of adsorption material technology. Through a stepwise functionalization and sequential crosslinking method, thiourea groups are first introduced onto the chitosan microspheres, followed by the introduction of tertiary amine groups and secondary crosslinking, successfully preparing chitosan microspheres possessing both thiourea and tertiary amine bifunctional groups. The thiourea and tertiary amine groups in the microspheres of this invention exhibit a synergistic adsorption effect on noble metal chloride anions, significantly improving the selective adsorption capacity and adsorption rate for noble metals such as palladium, platinum, and rhodium. Simultaneously, the dense three-dimensional network structure constructed through stepwise crosslinking greatly enhances the chemical stability and mechanical strength of the microspheres under strongly acidic environments, extending their service life. This preparation method is simple, mild, and environmentally friendly. The prepared adsorbent is particularly suitable for the efficient and selective recovery of noble metals from complex acidic wastewater or electronic waste leachates.

The invention provides a preparation method of a noble metal catalyst, which comprises the following steps: S1, carrying out hydrothermal treatment, drying and roasting on aluminum oxide to obtain aluminum oxide powder; s2, after titanium salt and zirconium salt are mixed according to a preset proportion, a diluent is added, and a precursor solution is obtained; dipping and mixing the aluminum oxide powder and the precursor solution according to a preset first mass ratio, and then washing, drying and roasting to obtain a titanium-zirconium-aluminum composite carrier; s3, mixing and grinding the titanium-zirconium-aluminum composite carrier, noble metal and an oxygen storage material according to a preset second mass ratio to obtain coating slurry; the noble metal is one or more of platinum, palladium and rhodium; s4, coating a target carrier with the coating slurry, and then drying and roasting to obtain the noble metal catalyst. Therefore, the catalytic efficiency and stability of the noble metal catalyst can be improved.

The invention discloses an endogenous Joule heat catalyst for methane dry reforming and a preparation method and application thereof, the endogenous Joule heat catalyst comprises a titanium black carrier and an active metal loaded on the titanium black carrier, the titanium black carrier is selected from at least one of Ti4O7, Ti5O9, Ti6O11, Ti7O13, Ti8O15 and Ti9O17, and the active metal is selected from at least one of Ti4O7, Ti5O9, Ti6O11, Ti7O13, Ti8O15 and Ti9O17. The active metal is at least one of nickel, cobalt, rhodium, ruthenium, palladium, platinum and iridium, and the endogenous Joule heat catalyst has an electro-thermal characteristic. Titanium oxide is used as a carrier, a conductive TiO layer exists in crystal lattices of the titanium oxide and has conductivity, CO2 can be directly activated by the conductive TiO layer containing a large number of oxygen vacancies, CH4 can be efficiently activated by the loaded active metal, the titanium oxide and the loaded active metal jointly form a bifunctional catalytic activity system, and the catalyst can be self-heated through endogenous Joule heat due to the electro-thermal characteristic; energy loss caused by indirect heat transfer of an electrothermal material in the prior art is avoided, current can directly flow through the catalyst, and the reaction performance is effectively improved by coupling the endogenous Joule heating effect and the electronic effect.

A method of hydrogenation includes contacting a catalyst, including rhodium nanoparticles in an amount of 0.9 percent by weight (wt. %) to 1.1 wt. % based on the total weight of the catalyst supported on alumina, with furfural in the presence of ethanol to form a reaction mixture. The method further includes heating the reaction mixture at a pressure, at a temperature, and for a time, in a hydrogen gas atmosphere to form a hydrogenated product including furfuryl ethyl ether. At least 99 wt. % of the furfural is reacted to form the furfuryl ethyl ether and the furfuryl ethyl ether is formed with at least a 99 wt. % selectivity.

The invention relates to a method for transferring rhodium in rhodium-containing organic waste liquid to a water phase through two-phase oxidation, and belongs to the technical field of precious metal regeneration metallurgy. A two-phase oxidation transfer system is adopted, and a chlorine-containing water phase is added into an in-situ active chlorine electrolysis unit for in-situ electrolysis to generate an active chlorine water phase; the method comprises the following steps: introducing carbon monoxide and an active chlorine water phase into a two-phase contact unit, fully mixing and contacting with the pretreated rhodium-containing organic waste liquid, sequentially carrying out multi-stage oxidation-transfer reaction to obtain an oxidation-transfer reaction mixture, introducing the oxidation-transfer reaction mixture into a phase separation unit, and carrying out gravity separation to obtain a lower rhodium-containing water phase and an upper organic phase, an upper-layer organic phase returns to the first-stage mixing unit or the organic phase collecting unit through a three-way pipe I according to the content of the rhodium element, and a lower-layer rhodium-containing water phase flows into the in-situ active chlorine electrolysis unit through a three-way pipe II or flows into the water-phase product collecting unit as a rhodium-rich water phase through the three-way pipe II. According to the method, the stable treatable rhodium-rich water phase is obtained, and meanwhile, the organic phase is reserved and recycled.

The invention relates to a novel functional material for X-ray protection, in particular to a liquid metal flexible shielding material and a preparation method and application thereof. The material comprises liquid metal and solid metal, the liquid metal serves as a solvent to be filled in gaps of the solid metal, the liquid metal is gallium, gallium indium, gallium indium tin, gallium indium tin zinc or mercury, and the solid metal is selected from one or more of indium, tin, gold, platinum, iridium, zirconium, niobium, molybdenum, ruthenium, osmium, rhenium, rhodium, tungsten, antimony, palladium, tantalum, hafnium, lutetium, lead, ytterbium, thulium, bismuth, silver, erbium, holmium, dysprosium, terbium, gadolinium, samarium, neodymium, lanthanum, praseodymium, cerium and europium. On the basis of compounding of the liquid metal solvent and the solid metal solute based on the liquid metal combinatology, the liquid metal and the solid metal are jointly used for protecting X-ray radiation, the comprehensive performance of X-ray protection is improved, and meanwhile the variety and number range of selectable metal elements is widened.

Disclosed is an apparatus for conversion of ammonia into oxides of nitrogen which may comprise an adiabatic burner (108), a set of platinum / rhodium alloy catalytic gauzes (102A), (102B), and (102C), a waste heat recovery boiler (WHRB) (110), an absorption tower (302A), (302B), (302C), (302D) and (302E), a NaOH tank (306) and a surge tank (304). Further, the adiabatic burner may be configured to carry out catalytic oxidation of air and ammonia, using catalytic gauzes (102A), (102B), and (102C) of platinum / rhodium alloy. Further, the mixture of air and ammonia may be selectively oxidized to oxides of nitrogen, which may be absorbed in an alkali medium in the absorption tower (302A), (302B), (302C), (302D) and (302E), to yield sodium nitrites and nitrates.

The invention provides a fly ash fiber and a preparation method thereof, and belongs to the technical field of fly ash, the preparation method specifically comprises the following steps: firstly, mixing a fly ash raw material with a composite oxidant and a dispersant, the composite oxidant comprises a main oxidant and an auxiliary oxidant, the main oxidant is potassium permanganate, and the auxiliary oxidant is sodium hydroxide; the auxiliary oxidant is manganese dioxide; carrying out ball milling treatment on the obtained mixture, and drying to remove the dispersing agent to obtain a homogenized mixture; then placing the mixture in an air atmosphere, heating to a first preset temperature and preserving heat for a first preset time, then heating to a second preset temperature and preserving heat for a second preset time to prepare clinker liquid, and then quenching the clinker liquid to obtain glassy clinker; and finally, drawing and forming the glassy clinker through a platinum-rhodium alloy bushing plate to obtain the fly ash fiber.

The invention provides a method for leaching precious metal from a waste catalyst containing precious metal, which comprises the following steps: mixing hydrochloric acid and an oxidizing agent to obtain a leaching agent, and mixing the waste catalyst containing precious metal with the leaching agent to obtain mixed slurry; and performing ultrasonic-microwave synergistic leaching treatment on the mixed slurry, and performing solid-liquid separation to obtain filter residues and a precious metal-rich leachate. According to the method, the leaching agent prepared from hydrochloric acid and the oxidizing agent is used, the precious metal in the waste catalyst containing the precious metal can be activated without using the leaching agent such as aqua regia which is prone to generating nitrogen-containing waste gas, generation of toxic gas is avoided from the source, and green and environment-friendly processes are achieved; meanwhile, ultrasonic-microwave synergistic leaching is utilized, a physical barrier is broken through ultrasonic, a reaction interface is maximized, microwave provides efficient heat energy and activates molecules, the chemical reaction rate of the interface is greatly increased, the synergistic strengthening effect is generated, and then the leaching rate of precious metal, especially rhodium, is greatly increased.

The invention discloses a method for preparing primary amine chemicals by hydrogenation amination of aldehyde and ketone through a platinum group monatomic doped nickel-based layered hydroxide catalyst, and belongs to the technical field of heterogeneous catalysis preparation of high-quality chemicals. The method comprises the following steps: by taking aldehyde and ketone chemicals as raw materials and ammonia gas as a gas source, carrying out hydrogenation amination reaction in a reaction solvent under the action of a platinum group monatomic doped nickel-based layered hydroxide catalyst and a hydrogen atmosphere to prepare a primary amine chemical; the platinum group single atom is any one of palladium, platinum, ruthenium, iridium or rhodium; wherein the effective active components on the nickel-based layered hydroxide carrier are composed of nickel metal and other metals, and the other metals are one or more of zinc, magnesium, aluminum, cerium, manganese, zirconium, iron, niobium or copper. The primary amine chemical prepared by the method has very high economic value.

An olefin compound may be produced by a process that may include passing a feed stream to a reactor, wherein the feed stream comprises one or more hydrocarbons; and transferring an oxygen carrier material into the reactor. In the reactor, the one or more hydrocarbons may be dehydrogenated to form hydrogen and one or more olefin compounds, and at least a portion of the hydrogen may be reacted with oxygen from the oxygen carrier material to produce water. The oxygen carrier material may include a first composition. At least 95% by weight of the first composition may consist of: 1 mole parts of iron; 0.1 to 1 mole part of one or more alkali metals; 0.001 to 3 moles of a combination of one or more of calcium, magnesium, strontium, barium, cerium, molybdenum, tungsten, copper, nickel, manganese, rhodium, silver, gold, palladium, or platinum; and 1 to 20 parts by mole of oxygen.

The present invention relates to silver nanoclusters doped with rhodium hydride, a method of producing the same, and an electrochemical catalyst for hydrogen gas generation. The silver nanoclusters doped with rhodium hydride of the present invention have utility as an electrochemical catalyst, have a significantly low production cost compared to a platinum (Pt) catalyst according to the related art, and exhibit an effect of generating hydrogen gas equal to or greater than that of the Pt catalyst.

This invention provides a collector for recovering platinum group metals (PGMs) from spent catalysts, its preparation method, and its application, belonging to the technical field of precious metal recovery. The collector comprises a copper matrix, a flux, a framework support, and a lattice activator: the copper matrix, flux, and lattice activator are loaded on the surface of the framework support; the copper matrix is ​​elemental copper or a copper-based compound; the flux is boric acid or a borate; the framework support is a porous inorganic material; and the lattice activator is tin, a tin alloy, or a metal sulfide. The collector serves as a collector for the pyrometallurgical recovery of PGMs from spent catalysts. This invention constructs a multi-component synergistic collector composed of a copper matrix, flux, framework support, and lattice activator, which significantly improves the recovery rate of PGMs, especially rhodium, from spent automotive exhaust purification catalysts in pyrometallurgical treatment, and reduces the smelting temperature required for pyrometallurgical treatment, thus significantly reducing energy consumption.

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.

The application discloses a method for preparing di-tert-butyl dicyclohexyl-18-crown-6 by hydrogenating di-tert-butyl benzene-18-crown-6, wherein the catalytic system comprises a high-loading rhodium catalyst with a content of 3-10 wt% and a low-loading rhodium catalyst with a content of 0.05-1 wt%, which are prepared respectively and physically mixed to form active site distribution with different metal surface densities, and the catalyst is prepared by a deposition precipitation method so that Rh particles are uniformly dispersed on the surface of an alumina carrier. The system can realize efficient aromatic crown ether hydrogenation under mild conditions and has a good industrial application prospect.

This invention provides a neutral-electron-reversed carbene, its preparation method, and its applications, belonging to the fields of organic chemistry and organic catalysis. The neutral-electron-reversed carbene described in this invention has the structure shown in formula (I). This invention synthesizes the neutral-electron-reversed carbene in one step by reacting a diazo compound as a precursor with a rhodium complex, followed by nitrogen removal and COD (1,5-cyclooctadiene) removal processes. The reaction conditions of this invention are simple, and the yield is good. Stable separation of neutral-electron-reversed carbene is achieved for the first time.