493 results about "Palladium" patented technology

The invention provides a method and system for detecting the content of platinum, palladium and rhodium in an automobile exhaust purification catalyst and application, and relates to the technical field of automobile exhaust purification, the method comprises the following steps: crushing, grinding, sieving, performing microwave acidolysis, neutralizing, washing and drying a catalyst sample to obtain dry filter residues; a trapping agent and a fluxing agent are added into the dry filter residues, constant-temperature heating is conducted in inert gas, then cooling forming is conducted, and an alloy button is obtained; blowing ash on the alloy, then adding mixed acid into the alloy, heating the alloy in a water bath at 95 DEG C for 25-35 minutes to obtain a dissolved solution, then adding a masking agent into the dissolved solution, and oscillating to obtain a solution to be detected; and filtering the liquid to be detected, fixing the volume and detecting. According to the method, precise quantification of trace platinum, palladium and rhodium in the complex matrix catalyst can be realized, and the method has a relatively high recovery rate; meanwhile, pollution elements are prevented from being used, and the method is green and efficient and better conforms to the concept of green chemistry.

The invention relates to the technical field of precious metal recovery, in particular to a process for separating precious metal from copper-nickel smelting waste, which comprises the following steps: crushing and grading the waste, adding a sulfuric acid solution containing etidronic acid, leaching, and washing, drying and crushing filter residues to obtain a pretreated material; mixing the pretreated material with a sodium peroxide-sodium carbonate composite flux, roasting, leaching with water, and filtering to obtain a filter residue B; adding a leaching agent containing hydrochloric acid, sodium chlorate and 1, 2-cyclohexanediamine tetraacetic acid into the filter residue B according to the ratio of 1: 3-1: 5, and filtering to obtain filtrate C and filter residue C; adjusting the pH value of the filtrate C to 1.5-2.5, adding an ethanol solution of sodium N, N-diethyldithiocarbamate, precipitating, washing and calcining to obtain sponge palladium; adding ammonium chloride into the filtrate D, precipitating and calcining to obtain sponge platinum; and leaching the filter residue C by using a hydrochloric acid-chloroauric acid mixed solution containing diphenylthiourea, and replacing and calcining zinc powder to obtain crude gold. According to the process, the leaching rates of platinum, palladium and gold and the product purity are greatly improved; flux and reagent systems are optimized, consumption and energy consumption are reduced, waste liquid treatment is matched for up-to-standard discharge, and efficient resource recovery and environment-friendly cooperation are achieved.

The invention discloses a comprehensive treatment method of platinum and palladium slag, and relates to the technical field of non-ferrous metal metallurgy. After the platinum and palladium slag is subjected to sulfating roasting, flue gas is introduced into a selenium absorption tower; hydrolyzing the roasting slag, reducing the dissolving solution to recover tellurium, and enabling the dissolving solution to enter a copper recovery process after tellurium precipitation; the dissolving slag is subjected to chlorination dissolution gold separation, and the gold separation slag is subjected to silver recovery; the gold separation liquid is reduced to obtain gold powder; carrying out platinum and palladium precipitation on the gold reduced solution, adding ammonia water into platinum and palladium precipitation to carry out platinum and palladium separation, respectively refining the separated platinum and palladium, and recovering platinum and palladium; carrying out platinum-palladium reduction on the platinum-palladium precipitation post-solution to obtain platinum-palladium precipitation slag and a platinum-palladium reduction post-solution, and returning the platinum-palladium precipitation slag to the roasting process; and performing tellurium reduction on the platinum-palladium reduced liquid to obtain tellurium powder and tellurium reduced liquid, and enabling the tellurium reduced liquid to enter a wastewater treatment process. The method has the beneficial effects that selenium, tellurium, copper, gold, silver, platinum and palladium are separated and recycled step by step, the recycling rate is high, the wastewater treatment difficulty is small, and environmental pollution is reduced.

A method may include operating a dehydrogenation process whereby a hydrocarbon-containing feed is converted to light olefins, wherein the dehydrogenation process utilizes a fluidized process catalyst that circulates between a reactor and a combustor. The method may comprise withdrawing the process catalyst from the dehydrogenation process, modifying the process catalyst to form a modified catalyst, and adding the modified catalyst back to the dehydrogenation process. The process catalyst may include from 0.1 wt. % to 10 wt. % of one or more metals chosen from gallium, indium, thallium, or combinations thereof, from 1 ppmw to 1000 ppmw of one or more metals chosen from platinum, palladium, rhodium, iridium, ruthenium, osmium, or combinations thereof, and at least 85 wt. % support. Modifying the process catalyst may include adding one or more of manganese, iron, chromium, or vanadium.

The invention discloses a hydrogen energy fuel cell catalyst carrier based on a graphene graft polymer, which is characterized in that two-dimensional graphene is used as a substrate, the surface of the two-dimensional graphene is modified with an oxygen-containing functional group, and a functional polymer branch chain containing nitrogen, sulfur or phosphorus heteroatoms is covalently grafted to form a local three-dimensional network winding structure; the carrier is loaded with platinum, palladium, ruthenium and other metal or alloy nanoparticles, the particle size is 2-8 nm, the loading capacity is 10%-40%, and the particles are anchored to polymer functional sites or reduced in situ to a graphene defect area through coordination. A polymer branch chain has pH responsiveness and can adjust the local proton transmission efficiency; the grafting density is 3-15 grafting points per 100 carbon atoms, so that high dispersion and stable anchoring of metal particles are effectively realized; the specific surface area of the carrier is 400-800m < 2 > / g, the electrochemical active area is not less than 80m < 2 > / g, and the activity retention rate is greater than 80% after 5000 circles of accelerated durability tests. The activity, the stability and the proton conduction performance of the catalyst are remarkably improved, and the catalyst is suitable for high-performance fuel cells.

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.

A method may include contacting a hydrocarbon-containing feed with a catalyst in a reactor to form an olefin-containing effluent, then at least partially separating the olefin-containing effluent from the catalyst. Passing the catalyst to a combustor and heating the catalyst by combusting a supplemental fuel. The supplemental fuel includes methane in an amount greater than or equal to 1 mol. %. Passing the catalyst from the combustor to the reactor, such that at least a portion of the catalyst continuously cycles between the reactor and the combustor. The catalyst includes from 0.1 wt. % to 10 wt. % of one or more metals chosen from gallium, indium, thallium or combinations thereof, from 5 ppmw to 1000 ppmw of one or more metals chosen from platinum, palladium, rhodium, iridium, ruthenium, osmium, or combinations thereof, from 100 ppmw to 30000 ppmw of chromium, and at least 85 wt. % support.

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.

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 discloses low-activity sintering-resistant silver powder and a preparation method thereof, and belongs to the technical field of precious metal powder materials. The preparation method comprises the following steps: S1, dissolving a reducing agent and a dispersing agent in water, adding a silver nitrate solution, and reacting to obtain a seed crystal solution; s2, adding the seed crystal solution into a dispersing agent solution, and adding a silver nitrate solution and a reducing agent solution at the same time to obtain a reaction mixture; and S3, the reaction mixture is subjected to impurity removal, drying, crushing and sieving, and the low-activity sintering-resistant silver powder is obtained. The prepared silver powder is large in particle size, high in tap density, small in specific surface area and low in burning loss, and is mainly applied to silver-palladium resistance paste or silver-palladium-platinum resistance paste of a thick film heating module.

A catalyst suitable for dehydrogenation of hydrocarbons may include from 0.0005 wt.% to 0.1 wt.% of platinum, palladium, rhodium, iridium, ruthenium, osmium, or combinations thereof; from 0.1 wt.% to 10 wt.% of gallium, indium, thallium, or combinations thereof; from 0.1 wt.% to 5 wt.% of lanthanum, yttrium, or zirconium; at least 85 wt.% support, and from 0 wt.% to 0.001 wt.% cerium.

Provided are: a hydrogen separation filter which has a high hydrogen permeation rate and which prevents or reduces separation between layers; and a method for producing the hydrogen separation filter. The hydrogen separation filter includes a porous substrate and a palladium layer provided on the porous substrate. The grain boundary number density observed in a cross-sectional secondary electron image of the palladium layer is 1-5 grains / [mu] m. A method for manufacturing a hydrogen separation filter includes forming a palladium layer on a porous base material by a sputtering method while keeping the temperature of the porous base material at 300-600 DEG C.

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 invention discloses an enzyme-bimetal monatomic composite catalyst as well as a preparation method and application thereof, and belongs to the technical field of biology. The technical problem to be solved is to improve the detoxification effect on mycotoxins (AFB1, ZEN, T-2, DON and OTA). According to the technical scheme, the enzyme-bimetal monatomic composite catalyst is characterized by comprising a framework, bimetal and enzyme, the sum of the loading capacities of the double metals on the catalyst is 0.1-5 wt%, and the loading capacity of the enzyme on the catalyst is 0.1-0.4 mg / mg; and the bimetals are two of palladium, gold, silver, ruthenium, platinum, iron, zinc and zirconium.

The invention relates to an amino silane coupling agent modified halloysite nanotube mercury-free catalyst for acetylene hydrochlorination reaction. The catalyst comprises a carrier and an active component. The carrier is a halloysite nanotube modified by one or more amino silane coupling agents. The active component is one or a combination of more of halides and complexes of precious metals such as gold, silver, rhodium, palladium, platinum and ruthenium, and the mass ratio of the single active component to the carrier is 0.01-1%. The preparation method of the catalyst adopts a preparation method combining a reflux method and an ultrasonic / microwave-assisted impregnation method, and comprises the following two steps: 1) grafting an amino silane coupling agent by adopting the reflux method to modify halloysite nanotubes; and 2) loading an active component on the halloysite nanotube obtained in the step 1) by using an ultrasonic / microwave-assisted impregnation method.The catalyst prepared in the invention shows good catalytic performance in an acetylene hydrochlorination reaction process, the acetylene conversion rate reaches 97.34%, and the vinyl chloride selectivity reaches up to 99.68%.

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 relates to a carbon-supported noble metal ordered alloy electrocatalyst capable of realizing mass production. The electrocatalyst comprises a carbon carrier and small-size noble metal ordered alloy nanoparticles loaded on the carrier, the loading capacity of the alloy is 20 to 90 weight percent; the average particle size of the precious metal ordered alloy nanoparticles is 1-10 nm; the noble metal ordered alloy comprises an alloy consisting of a noble metal and at least one different transition metal M; wherein the noble metal is platinum, palladium, iridium, rhodium or ruthenium. The method is used for solving the problem that the size of catalyst particles becomes large in the high-temperature ordering process, high metal loading capacity is achieved, the feed ratio is increased to 60 times, successful synthesis of the catalyst can be achieved on the gram scale level, and the method can be popularized to actual production to achieve large-scale production.

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.

The invention belongs to the field of analytical chemistry, and particularly discloses a method for determining trace precious metals in copper-nickel flotation tailings. According to the method, trace precious metal in the tailings is enriched through a nickel matte assaying method, and nickel matte alloy rich in precious metal is formed; the nickel matte alloy is inlaid or crushed and doped with carbon to prepare a sample meeting the measurement requirement of the glow discharge mass spectrometry, and the content of the noble metal in the sample is measured and converted by adopting the glow discharge mass spectrometry. The method effectively solves the problems of low precious metal content in tailings and large fluctuation of detection results, improves the detection accuracy and stability, and is suitable for determination of trace precious metals such as gold, silver, platinum, palladium, rhodium and iridium.

The invention provides a plasmon metal catalyst as well as a preparation method and application thereof. The plasmon metal catalyst comprises a gold nanostructure and a palladium-modified indium nanostructure loaded on the surface of the gold nanostructure, the mass ratio of the palladium-modified indium nanostructure to the gold nanostructure is (1-25): 1. The preparation method disclosed by the invention is simple, convenient, feasible and low in operation cost, and is a simple, convenient and economical synthesis method. According to the invention, the variety and quality of sites are accurately regulated and controlled, the CH2 * intermediate is stabilized through the interaction of indium and palladium, the * CH2-CH2 * coupling is promoted, and the C-C coupling energy barrier is reduced; the desorption capacity of C2H4 * can be improved by palladium, and conversion of carbon dioxide into high-added-value products is promoted; the plasmon metal catalyst provided by the invention has good photoresponse performance and high carrier concentration, is stable in structure and can be recycled, the conversion from solar energy to chemical energy can be effectively improved, and the consumption of a large amount of energy in the traditional industrial process is avoided.

The invention relates to the technical field of electro-catalysis, in particular to a metal monatomic doped copper-based catalyst and a preparation method and application thereof. The metal single atoms in the catalyst are selected from palladium single atoms, iron single atoms, nickel single atoms or ruthenium single atoms; the doping amount of the metal single atoms is 0.5%-1.0% on the basis of the total mass of the catalyst. The invention provides a novel metal monatomic doped copper-based catalyst, which can be used for catalyzing the reduction of a harmful substance nitrite into a chemical ammonia with an economic added value by using renewable electric power, can solve the problems of nitrite pollution and environment and energy caused by ammonia production by a Have-Bosch method, and realizes the purpose of turning waste into wealth.

The application discloses a comprehensive treatment method of platinum-palladium slag and relates to the technical field of nonferrous metal smelting. After sulfuric acid roasting of the platinum-palladium slag, flue gas is introduced into a selenium absorption tower; the roasted slag is hydrolyzed, and tellurium is recovered by reduction of a dissolved solution; after the tellurium is precipitated, the dissolved solution is introduced into a copper recovery procedure; gold is recovered by chlorination and dissolution in the dissolved slag, and the gold-recovered slag is introduced into silver recovery; gold powder is obtained by reduction of the gold-recovered solution; platinum and palladium are precipitated from the gold-reduced solution; ammonia is added to the platinum and palladium precipitate to separate platinum and palladium; the separated platinum and palladium is refined to recover platinum and palladium; platinum and palladium are reduced from the platinum and palladium precipitated solution to obtain platinum and palladium precipitate and platinum and palladium reduced solution, and the platinum and palladium precipitate is returned to the roasting procedure; tellurium is reduced from the platinum and palladium reduced solution to obtain tellurium powder and tellurium reduced solution, and the tellurium reduced solution is introduced into a wastewater treatment procedure. The application has the beneficial effects that selenium and tellurium, copper, gold, silver, platinum and palladium are stepwise separated and recovered, the recovery rate is high, the wastewater treatment difficulty is small, and environmental pollution is reduced.

The invention relates to a high-hardness and high-strength palladium-silver-copper-nickel quaternary alloy rod for a probe and a preparation method thereof, and the palladium-silver-copper-nickel quaternary alloy rod comprises the following elements in percentage by mass: 30-38% of Pd, 40-46% of Cu, 10-20% of Ag and 8-15% of Ni. The sum of the mass of Ag and Ni is 18-30%, and the sum of the mass of Pd and Ni is 41-50%; the hardness of the palladium-silver-copper-nickel quaternary alloy bar subjected to heat treatment is larger than 300 HV, and the strength is larger than 1000 MPa. According to the invention, nickel with low cost is used as an important strengthening element and cooperates with silver and copper to realize strengthening in an alloy matrix with low palladium content, and an efficient quality-improving forming process is matched, so that the balance of high hardness and high strength of the alloy is realized on the premise of controllable cost, and the harsh demand of a test probe can be met.

A low-temperature dehydrogenation method includes a dehydrogenation reaction of a reactant including a piperidine-based compound substituted with one or more alkyl groups. The dehydrogenation reaction takes place in the presence of a catalyst including an active metal. The active metal includes platinum (Pt), palladium (Pd), or a mixture thereof that is supported on a carrier including a composite metal oxide having alumina (Al2O3) and an additional metal oxide different from alumina, at a low temperature of 150° C. to 250° C., to produce hydrogen.

A platinum alloy composition is composed of, in weight percent, 0.0 to 5.0 gold, 0.0 to 2.5 cobalt, 0.0 to 3.0 copper, 0.0 to 5.0 iron, 0.0 to 2.75 gallium, 0.0 to 3.0 indium, 0.0 to 5.0 iridium, 0.0 to 5.0 manganese, 0.0 to 5.0 palladium, 0.0 to 5.0 rhenium, 0.0 to 5.5 rhodium, 0.0 to 5.0 ruthenium, 0.0 to 3.0 tin, 0.0 to 5.0 silver, and incidental impurities, where the sum of platinum and iridium is 95.0 or more, and wherein the following formula is satisfied, in which the sum of platinum and iridium is 95.0 or more. WCo, WCu, WFe, WGa, WIn, WNi, WPd, WSn, WRh, WIr, WAu, WRu, WRe, WAg and WMn are respectively weight percentages of cobalt, copper, iron, gallium, indium, nickel, palladium, tin, rhodium, iridium, gold, ruthenium, rhenium, silver and manganese in the alloy, 60 + WPd * 2.5 + WRh * 3.4 + WIr * 6.455 + WIr * 16.6 + WNi * 16.9 + WMn * 18.48 + WCo * 18.69 + WFe * 21.879 + WIn * 29 + WSn * 28.207 + WGa * 42.379 + WAg * 9.0 > = 130, and wherein the following conditions are satisfied, in which the weight percentages of cobalt, copper, iron -0.10406 * WAg-0. 1028 * WCo-0. 1201 * WCu-0. 2113 * WFe-0. 3368 * WGa-0. 1125 * WIn-0. 1639 * WNi-0. 0959 * WSn + 17.276261-0.20 * WMn + 0.0678 * WRu + 0.035 * WIr + 0.045 * WRh-0. 059 * WAu + 0.066 * WRe < = 17.1, and wherein the following formula is satisfied in which WCo, WCu, WFe, WGa, WIn, WNi, WPd, WSn, WMn, WRu, WIr, WRh, WAu, WAg and WRe are respectively aluminum, cobalt, copper, iron, gallium, indium, nickel, palladium

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.

This invention discloses a proton exchange membrane hydrogen pump anode and its application. The anode includes an anode sheet and a catalyst composited on the anode sheet. The catalyst includes a support and a first metal and a second metal composited on the support. The first metal is selected from one or more of platinum, iridium, palladium, and ruthenium; the second metal is selected from one or more of iron, cobalt, nickel, molybdenum, and vanadium. The first metal serves as the main active center for the hydrogen oxidation reaction, and the second metal can regulate the electronic structure of the first metal, thereby reducing the adsorption of carbon monoxide at the active site or promoting its oxidative removal. The synergistic effect of the two metals allows the anode containing the catalyst to maintain high hydrogen oxidation activity and stability in hydrogen fuel containing carbon monoxide, thereby improving the carbon monoxide poisoning resistance of the proton exchange membrane hydrogen pump containing the anode.

The present disclosure relates to a method for oxidation of mercaptans, comprising the following steps: contacting mercaptan compounds with a catalyst for oxidation reaction in the presence of oxygen; the catalyst is a composite catalytic material, which comprises a full-silica molecular sieve and a metal element M dispersed in the intracrystalline of the full-silica molecular sieve; the metal M is selected from one or more of manganese, iron, cobalt, nickel, palladium, platinum, copper and gold. The present disclosure uses a metal-containing hierarchical porous molecular sieve for mercaptan oxidation and dehydrogenation reaction, without adding additional alkali, high conversion rate and disulfide selectivity can be obtained at a lower temperature, which has high industrial application value.