4299 results about "Precious metal" patented technology

The invention relates to an electronic waste automatic classification and recovery system based on artificial intelligence recognition. The electronic waste automatic classification and recovery system comprises a waste conveying module, an artificial intelligence recognition module, an intelligent sorting module, a dynamic sorting control system, a recovery processing module and a data analysis and feedback module. The waste conveying module conveys the electronic waste to a recognition area in order, and the recognition module conducts multi-dimensional feature recognition on the waste through vision, spectrum and 3D morphological analysis technologies. And the intelligent sorting module sorts the materials to a specified sorting box according to the recognition result. The dynamic sorting control system can adjust a sorting path in real time according to task requirements. And the recovery processing module is used for further processing the sorted materials through a crushing device, a magnetic separation device and a rare and noble metal extraction device. And the data analysis and feedback module analyzes and optimizes data of identification and sorting operation, so that the processing efficiency and the recovery rate are improved.

The invention discloses a preparation process of a modified porous carbon material catalyst. The preparation process comprises the following steps: (1) mixing and calcining a biomass precursor and a template agent to prepare graded porous carbon; (2) low-frequency plasma pretreatment and high-frequency plasma fluorination modification are adopted; (3) introducing the pulse plasma into a nitrogen doping site; (4) spraying ionic liquid and activating H2 plasma to form a B / F co-doped layer; and (5) loading alloy nanoparticles such as PtRu through pulse electrodeposition. According to the obtained catalyst, biomass derived porous carbon serves as a carrier, a fluorine / nitrogen co-doped active layer is constructed on the surface of the carrier through multi-frequency plasma synergistic modification and ionic liquid auxiliary modification, superfine precious metal nanoparticles are loaded, the hydrogen evolution overpotential of the catalyst is smaller than or equal to 28 mV under the current density of 10 mA / cm < 2 >, the activity attenuation is smaller than 5% after 1000 times of circulation, and the catalyst has a good catalytic activity. The water electrolysis hydrogen production device is suitable for a large-scale water electrolysis hydrogen production device.

The invention discloses a titanium base material bipolar plate corrosion-resistant and hydrogen embrittlement-resistant composite coating and a preparation method thereof. The surface of a titanium base material is sequentially coated with a titanium transition layer, a titanium black hydrogen resistance layer, a titanium hole sealing layer and a precious metal conducting layer; the titanium transition layer is an elemental titanium layer, and the thickness of the titanium transition layer is 10-30 nm; the material of the titanium black hydrogen blocking layer is Magneli-phase titanium black with the molecular formula of TinO2n-1, wherein n is greater than or equal to 4 and less than or equal to 10, and the thickness is 100-150nm; the titanium hole sealing layer is an elemental titanium layer, and the thickness of the titanium hole sealing layer is 10-50nm; the precious metal conducting layer is made of at least one of platinum, gold, ruthenium and iridium, and the thickness of the precious metal conducting layer is 20-50 nm. The corrosion-resistant and hydrogen embrittlement-resistant composite coating disclosed by the invention can effectively block diffusion and permeation of hydrogen in a cathode environment of a PEM water electrolyser while ensuring corrosion-resistant and conductive performance, so that the hydrogen embrittlement-resistant performance of the cathode side of the bipolar plate is greatly improved, and the processing cost and the process complexity of the coating are reduced.

The invention discloses a hot-rolled high-weather-resistance steel plate with extremely low yield ratio and 850 MPa-grade tensile strength as well as a manufacturing method and application of the hot-rolled high-weather-resistance steel plate. The steel plate comprises chemical components in percentage by weight as follows: 0.06%-0.08% of C, 0.40%-0.60% of Si, 0.40%-0.60% of Mn, smaller than or equal to 0.015% of P, smaller than or equal to 0.005% of S, 2.50%-3.00% of Cr, 0.25%-0.30% of Cu, 0.13%-0.15% of Ti, 0.020%-0.040% of Alt, smaller than or equal to 0.0040% of N, smaller than or equal to 0.0030% of O and the balance of Fe and inevitable impurities. The high Cr + high Ti design is adopted, the tensile strength reaches 850 MPa, the weather resistance index I value is larger than or equal to 8.0, addition of precious metal Ni is omitted, the addition amount of the strong hardenability element Cr in the steel exceeds 2.50%, a fine grain ferrite and bainite double-phase structure is obtained in combination with the controlled rolling and controlled cooling process, meanwhile, the precipitation strengthening and fine grain strengthening effects of Ti are fully exerted, control over high strength and the extremely-low yield ratio smaller than 0.65 is achieved, and the high-strength and low-yield-ratio steel is obtained. The forming performance is excellent, the corrosion rate is smaller than 40% relative to Q345B, and good atmospheric corrosion resistance is achieved.

The invention provides a supported catalyst as well as a preparation method and application thereof. The preparation method of the supported catalyst comprises the following steps: S1, carrying out precipitation reaction on vanadate and first ammonium salt in a first solvent to obtain a first product system containing a carrier precursor; s2, enabling the carrier precursor, a second ammonium salt, a noble metal-containing compound, a chelating agent and a first reducing agent to react in a second solvent to obtain a second product system containing a catalyst precursor; and S3, carrying out annealing treatment on the catalyst precursor and a second reducing agent in protective gas to obtain the supported catalyst. The noble metal in the supported catalyst prepared by the method is not easy to migrate and aggregate, and the stability is better. In addition, the dosage of precious metal needed by the preparation method is smaller, and the atom utilization rate is higher.

The invention provides a mineral leaching property analysis method, which belongs to the field of process mineralogy, and comprises the following steps: crushing and enriching a sample to be detected, and selecting single mineral particles to obtain target mineral particles; the preparation method comprises the following steps: coating a sample preparation grinding tool with epoxy resin glue, adding target mineral particles, and carrying out curing and grinding treatment to obtain a primary sample; cutting the primary sample, placing the grinding surface downwards and the three wear-resistant alloys at the bottom of a sample preparation grinding tool, injecting epoxy resin glue, curing to form a composite sample, accurately grinding, polishing, performing carbon spraying treatment, performing first automatic mineralogical analysis, measuring the area of a target mineral, cleaning, and performing leaching treatment to obtain a treated sample; and after solidification, accurate grinding and polishing and carbon spraying treatment, secondary automatic mineralogical analysis is carried out, the area of the residual target mineral is measured, and the leaching index of the target mineral is calculated. Reliable technical support is provided for mineral processing technology optimization and resource evaluation, and the method is particularly suitable for development of efficient leaching technologies of precious metal, rare earth and the like.

The invention provides a TOPCon battery metallization method, and relates to the technical field of solar cells, and the method comprises the following steps: providing a blue diaphragm; preparing a metal seed layer on one side of the blue membrane and then drying; preparing a metal seed layer on the other side of the blue diaphragm, and then drying or sintering; preparing main and auxiliary grids on the metal seed layer on one side and then drying, wherein the main and auxiliary grids are made of non-silver paste; and preparing main and auxiliary grids on the metal seed layer on the other side, and sintering to complete metallization of the battery piece. In the invention, the main grid and the auxiliary grid are made of the non-silver paste, and the non-silver paste is used for replacing traditional silver paste, so that the use amount of silver is greatly reduced, the cost of raw materials is reduced, the production cost of the TOPCon battery is reduced, the dependence on noble metal resources is relieved when the TOPCon battery is produced, and the requirement of sustainable development is better met.

The invention discloses a high-entropy alloy / nitrogen-doped carbon nano catalytic material and a preparation method and application thereof.The nano catalytic material comprises a high-entropy alloy composed of five non-noble metals including Fe, Co, Ni, Cu and Mn and nitrogen-doped carbon synthesized with the assistance of MOF, the non-noble metal high-entropy alloy serves as a main body material, the nitrogen-doped carbon serves as a carrier material, and the nitrogen-doped carbon serves as a carrier material. A non-noble metal high-entropy alloy is loaded on nitrogen-doped carbon to construct a novel nano catalytic material, and the novel nano catalytic material is used for activating peroxydisulfate to remove antibiotics in a water body. The catalyst has the advantages of excellent chemical stability, good reusability and the like and is a novel nano catalytic material with efficient catalytic performance and environment-friendly characteristics, and the preparation method has the advantages of being simple in operation process, green, environmentally friendly, economical, feasible and the like and can be used for large-scale preparation.

The invention discloses a gas sensing material based on Ag / Pd-LaFeO3 and application of the gas sensing material in detection of hydrogen sulfide gas in municipal sewage, and relates to the technical field of gas sensing materials. The chemical formula of the gas sensing material based on Ag / Pd-LaFeO3 is X wt% of Ag-Y wt% of Pd-LaFeO3, wherein 0 lt; x < = 5, 0lt; y < = 5. According to the invention, on the basis of LaFeO3, the humidity interference resistance of the gas sensing material based on Ag / Pd-LaFeO3 can be improved through double noble metal surface modification of Ag and Pd. In addition, through double noble metal doping of Ag and Pd, the response sensitivity and selectivity of the prepared gas-sensitive material to H2S gas can be improved, and the working temperature of the gas-sensitive material is reduced. Specifically, at the working temperature of 110 DEG C, the response value of the prepared double noble metal modified LaFeO3 to 1ppm H2S gas is 46.16.

Alloy elements are reasonably matched, N and nitrides are added to form elements such as tungsten W, vanadium V, niobium Nb, cobalt Co, rare earth RE and the like for microalloying smelting, a forged and rolled material finished product is subjected to proper heat treatment, and the stainless steel subjected to heat treatment has good heat treatment performance through metallographic observation. According to the stainless steel, nanoscale carbides are separated out in a solid solution state, and fine particles mainly containing nitrides are dispersed and separated out in crystals in a thermodynamic state, so that the material is strengthened and does not diffuse to a crystal boundary, and the room-temperature mechanical property and the high-temperature mechanical property of the material are greatly improved; and when the stainless steel material produced by the method is used for manufacturing related products, the thickness of the stainless steel material can be reduced, and the overall input of the stainless steel material is greatly reduced, so that the large-scale application of noble metal strategic resource nickel is saved, and the aims of saving resources, energy and investment are fulfilled.

The invention relates to the technical field of wastewater resourceful treatment, in particular to a functional membrane for recycling precious metals in wastewater and a preparation method of the functional membrane. The specific preparation method comprises the following steps: preparing a polyamide spinning solution, carrying out electrostatic spinning on the spinning solution to form a polyamide fiber net, stably combining hollow mesoporous nano silicon dioxide on the fiber net through carboxymethyl chitosan, and grafting an epoxy silane coupling agent on the surface of the hollow mesoporous nano silicon dioxide to obtain the hollow mesoporous nano silicon dioxide fiber net. Finally, adipic dihydrazide is grafted on the hollow mesoporous nano silicon dioxide through a ring-opening reaction. Organic polyamide is used as a film forming substance, the raw material cost is low, the method is suitable for large-scale industrial production, the recovery rate of precious metal ions is high, and the film body has good mechanical strength and can stably operate for a long time.

The invention relates to the technical field of precious metal recovery, in particular to a precious metal recovery method which comprises the following steps: I, crushing a waste catalyst, blending the waste catalyst with sodium carbonate according to the weight ratio of 1: (0.5-1.2), and roasting at 700-1000 DEG C for 0.5-3 hours to obtain a roasted product; and II, dispersing the roasted product and sodium hydroxide in the weight ratio of (0.2-0.5): 1 in water at the temperature of 50-90 DEG C, stirring at the rotating speed of 80-320 r / min for 5-20 min for leaching, filtering while hot after leaching is finished, and collecting, washing and drying filter residues to obtain the recovered noble metal. According to the recycling method, the precious metal is efficiently recycled from the high-carbon-content catalyst by accurately controlling parameters of all the steps, and compared with a traditional recycling method, the recycling rate is remarkably increased, the influence on the environment is reduced, and meanwhile the production cost is reduced.

The invention discloses a long-life alumina crucible as well as a preparation method and application thereof. The raw material composition of the alumina crucible comprises pretreated quartz particles; the pretreated quartz particles are obtained through a pretreatment process; according to the pretreatment process, the surfaces of fused quartz particles are coated with a modifier through a granulation process, and the pretreatment process specifically comprises the steps that the fused quartz particles, the modifier and a binding agent are mixed, granulated and dried, and pretreated quartz particles are obtained. The fused quartz particle raw material is subjected to modification pretreatment, so that the crystallization behavior of fused quartz is reduced or inhibited, the stability of the fused quartz particles in the crucible firing and high-temperature service process is improved, and the binding property of the fused quartz particles and the fine powder component is enhanced, so that the mechanical properties such as breaking strength and fracture toughness of the alumina crucible are improved; therefore, the service life and the stability of the crucible are improved, and the performance of the alumina crucible can completely meet the requirement of the service life under extreme conditions in the fields of rare noble metal smelting and the like.

The invention relates to the technical field of reverse water-gas shift, in particular to a reverse water-gas shift catalyst, a preparation method thereof and a reverse water-gas shift method.The method comprises the steps that 1, precious metal is loaded on a carrier through an impregnation method, first calcination is conducted, and the carrier is selected from one or more of titanium dioxide, aluminum oxide, zirconium oxide and silicon dioxide; (2) mixing the product obtained in the step (1) with cerium dioxide, grinding, then carrying out secondary calcination, and reducing; the content of the noble metal element is 0.2-1wt% of the mass of the carrier; the mass ratio of the product obtained in the step (1) to cerium dioxide is 1: (0.5-2); and the noble metal is selected from one or more of rhodium, ruthenium and palladium. The reverse water gas shift catalyst prepared by the preparation method has the advantages of high carbon dioxide conversion rate, good carbon monoxide selectivity and stable catalytic performance when being used for reverse water gas shift reaction.

The invention relates to a non-noble metal-based self-supporting electrode, a preparation method thereof and application of the non-noble metal-based self-supporting electrode in efficient electrolyzed water. The self-supporting electrode comprises a non-noble metal substrate layer, and a transition layer and a catalytic activity layer which are sequentially arranged on the surface of the non-noble metal substrate layer, the transition layer comprises NiFe unit cell nano particles; the catalytic activity layer comprises CoFeLDH, and the CoFeLDH is of a cactus spherical structure formed by a nano needle-shaped array; and a heterojunction interface is arranged between the transition layer containing the NiFe unit cell nanoparticles and the catalytic activity layer containing the CoFeLDH. The catalyst has low oxygen evolution overpotential and has high current density and excellent stability under the working condition, the transition layer is constructed between the catalytic active layer and the foamed nickel substrate, interface contact between the catalytic active layer and the substrate can be optimized, more uniform stress distribution and better interface adhesion can be achieved, charge transfer and mass transfer are enhanced, and the catalytic activity of the catalyst is improved. Therefore, the electrode interface stability is realized.

The invention belongs to the technical field of rare and precious metal recovery, and particularly relates to a method for recovering metallic silver from waste crystalline silicon battery pieces, which comprises the following steps: (1) putting the waste crystalline silicon battery pieces into an inorganic alkali aqueous solution for soaking reaction to obtain an aluminum-containing solution and dealuminized crystalline silicon pieces; (2) adding the dealuminized crystal silicon wafer into a mixed solution of organic acid and hydrogen peroxide for soaking reaction, filtering and washing to respectively obtain silver-containing filtrate and a silver-removed silicon wafer; (3) carrying out chlorination precipitation reaction on the silver-containing filtrate and a chlorine source, filtering and drying to obtain silver chloride powder; (4) adding silver chloride powder into an ammonia water solution, heating and stirring to completely dissolve silver chloride to obtain a silver-ammonia solution; (5) adding PVP (Polyvinyl Pyrrolidone) into the silver-ammonia solution, heating and stirring until the PVP is completely dissolved, adding ascorbic acid, and carrying out reduction reaction at room temperature to obtain metal silver powder precipitate; and filtering, washing and drying the precipitate to obtain the spherical silver powder. According to the method, the silver recovery efficiency is high, the spherical nanoscale silver powder can be prepared, and the purity is high.

The invention belongs to the technical field of fuel cell non-noble metal catalyst material preparation, and particularly relates to a composite carbon nanofiber catalyst as well as a preparation method and application thereof. The preparation method comprises the following steps: firstly, combining metal ions with an organic ligand in an organic solvent at room temperature to successfully prepare a zeolite imidazate framework material (ZIFs); the preparation method comprises the following steps: carrying out primary carbonization on a prepared ZIFs material in an inert atmosphere high-temperature furnace to obtain a metal nitrogen carbon material, then uniformly mixing the metal nitrogen carbon material with a spinning solution, carrying out electrostatic spinning to obtain composite nanofibers, and then carrying out secondary carbonization in an inert atmosphere to finally successfully prepare the composite carbon nanofiber catalyst (MN-CNF). The catalyst has excellent electrocatalytic activity, can effectively improve the efficiency of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), and also has excellent catalytic stability.

The invention discloses a method for preparing fuel from waste polyolefin through noble-metal-free low-temperature aromatization, which comprises the following steps: in the atmosphere of synthesis gas, carrying out catalytic cracking on polyolefin serving as a raw material by adopting a binary mixed catalytic system to obtain aromatic hydrocarbon; the binary mixed catalytic system comprises Zr-ZnO and a molecular sieve; the catalytic cracking temperature is less than or equal to 300 DEG C. According to the low-temperature aromatization method disclosed by the invention, methanol is generated in situ through the synthesis gas, and the methanol and olefin generated by polyolefin cracking are subjected to Prins reaction, so that the aromatization reaction can be realized at the pyrolysis temperature far lower than that in the prior art, precious metals are not needed, the additional value and the application range of a plastic recovery product are greatly enhanced, and the method is suitable for industrial production. And the cost of the recovery process is reduced.

The invention discloses a method for recovering a silicon wafer and precious metal silver in a decommissioned crystalline silicon photovoltaic panel, which comprises the following steps of: 1, mechanically disassembling and pyrolyzing the decommissioned photovoltaic panel to obtain a crystalline silicon battery piece; 2, preparing molten salt, and heating the molten salt to melt the salt; and step 3, placing the crystalline silicon cell in molten salt, carrying out selective etching separation, taking out the crystalline silicon cell after etching is finished, and washing with water to obtain a silicon wafer and a silver wire. According to the method, the melting temperature of the used fused salt is low, silver and silicon in the photovoltaic panel can be separated in a targeted mode, the fused salt does not react with substrate silicon and silver wires on the surface, the high recovery efficiency of silver and silicon is guaranteed, meanwhile, environmental pollution caused by silver and silicon in the recovery process is reduced, on the basis, silver and silicon can be obtained through one-step separation and recovery, and the method is suitable for industrial production. The method has the advantages of simple operation, short process, environmental friendliness and the like.

The invention discloses a preparation method of deuterated carbazole under a hydrogen-free condition, which comprises the following steps: mixing carbazole, a catalyst and deuterium water, heating and reacting in an inert gas environment at the reaction temperature of 70-140 DEG C for 12-48 hours, filtering the mixed solution after the reaction is completed to obtain a mixture of deuterium water and a product, adding an organic extraction agent for extraction and liquid separation, and filtering to obtain the deuterated carbazole. Collecting an organic phase to obtain a product deuterated carbazole; according to the catalyst, gamma-type aluminum oxide serves as a carrier, an active component is precious metal alloy Pt-Ru, the mass of precious metal Pt accounts for 1%-30% of the mass of aluminum oxide, and the mass ratio of Pt to Ru is 1: (0.01-0.5). The catalyst has good reaction activity and stability in the reaction process, the synthesis method of the deuterated carbazole is simple and efficient, the deuterated carbazole can be synthesized at the temperature of 70 DEG C or above, the conditions are mild, meanwhile, the yield is high and at least can reach 60% or above, the operation process is simple and convenient, the catalyst is easy to prepare, and the production cost is low.

The invention provides a silver-coated copper material and a preparation method and application thereof. The silver-coated copper material comprises a base body and a silver layer coated on the surface of the base body, the base body comprises copper particles and a silver framework, the silver framework is provided with holes, the copper particles are distributed in the holes of the silver framework, and the silver layer is prepared by adopting a chemical plating method. The pore structure of the silver skeleton and the distribution of the copper particles are utilized, the separation of nucleation and growth of the silver coating is realized, the uniformity and compactness of the growth of the silver coating are ensured, the oxidation resistance and the conductivity of the silver-coated copper material are further improved, the use amount of precious metal silver is greatly reduced while the performance of the material is ensured, and the production cost is reduced. Cost control is realized; when the silver-coated copper material is applied to the fields of photovoltaic and electronic industry, the cost of raw materials can be remarkably reduced, the service life of the raw materials is prolonged, and large-scale use is facilitated.

Described herein are methods, devices, materials, and systems for extracting target materials from iron-rich feedstocks. The iron-rich feedstock may be red mud, a natural occurring mineral, and / or a waste stream. The target materials may include a main constituent of the feedstock, a rare earth element, a precious metal, and / or a platinum group element. The invention may use a combination of electrochemical reactions and physical separation methods.

The embodiment of the invention provides a water electrolysis hydrogen production catalytic electrode and a preparation method thereof, an electrolytic bath and a water electrolysis hydrogen production system.The provided water electrolysis hydrogen production catalytic electrode comprises a conductive substrate and a catalytic material layer deposited on the conductive substrate, the catalytic material layer comprises a nickel-based material, the surface of the catalytic material layer is provided with mountain-chain-shaped protrusions, and the mountain-chain-shaped protrusions are arranged on the surface of the catalytic material layer. The nickel-based material is used as the catalytic material layer, and mountain chain-shaped bulges are formed on the surface of the nickel-based material, so that not only can better binding force between the catalytic material layer and the conductive substrate be ensured, but also more active sites can be obtained on the surface of the catalyst, and the catalyst material shows better catalytic activity; therefore, the technical problem that an existing water electrolysis hydrogen production catalytic electrode cannot effectively give consideration to catalytic activity and stability can be effectively solved. In addition, the catalytic electrode for hydrogen production by electrolysis of water provided by the embodiment of the invention does not need to use noble metal, so that the production cost is relatively low.

The invention provides a modified doped lithium phosphorus sulfur chlorine solid electrolyte as well as a preparation method and application thereof, and belongs to the technical field of solid electrolytes. The Al and Cl double-doping mode can improve the mixing proportion of ions in lattices of Li6PS5Cl and expand ion channels, so that the ionic conductivity of the Li6PS5Cl system electrolyte and the stability to lithium are improved, and the ionic conductivity of the prepared modified doped lithium phosphorus sulfur chlorine solid electrolyte is larger than 3 mS / cm. The modified lithium-phosphorus-sulfur-chlorine-doped solid electrolyte provided by the invention is grey white powder in appearance, is uniform and free of foreign matters, and shows an argyrodite type, and the space group of a crystal structure is F43m. The preparation method of the modified doped lithium-phosphorus-sulfur-chlorine solid electrolyte is simple, the precursor can be obtained only by performing ball milling for 8 hours, rare and scattered noble metals are not used, and the production cost is reduced.

The bimetallic welding method comprises the steps that a plurality of annular grooves are formed in the surface, welded to a copper plate, of a steel base body, and a plurality of annular protrusions are formed on the surface of the steel base body; the steel substrate is placed on the lower electrode, and the copper plate is placed on the annular protrusion on the surface of the steel substrate; an upper electrode is placed on the copper plate, and set pressure is applied to the upper electrode; after the set pressure is reached, electrifying the upper electrode, and heating the annular bulge on the surface of the steel substrate to a molten or plastic state according to the generated resistance heat, so that the annular bulge is combined with the copper plate to finish welding; according to the double-metal welding method, the high-pressure energy storage welding process is used for replacing an original silver welding process using precious metal such as silver, and the cost is greatly reduced. Brass is used for welding, the welding method can be applied to the working condition higher than 400 bar, the abrasion resistance is high, and the product performance is improved.

The invention discloses a low-cost hydrogen embrittlement-resistant titanium bipolar plate for an electrolytic bath and a preparation method of the low-cost hydrogen embrittlement-resistant titanium bipolar plate. The low-cost hydrogen embrittlement-resistant titanium bipolar plate comprises a surface-modified titanium base material, an in-situ hydrogen-resistant layer formed on the surface of the titanium base material, and a noble metal conductive layer prepared on the surface of the in-situ hydrogen-resistant layer, the surface roughness Ra value of the titanium base material subjected to surface modification is 2-3.5 microns; the in-situ hydrogen-resistant layer is a titanium oxide layer or an oxygen inclusion layer which is generated on the surface of the titanium substrate in situ in an air atmosphere or an oxygen-enriched atmosphere, and the thickness of the in-situ hydrogen-resistant layer is 50-200nm; the precious metal conducting layer is made of at least one of platinum, gold, iridium and palladium, and the thickness of the precious metal conducting layer is 20-150 nm. Through simple surface modification and in-situ generation of the hydrogen-resistant layer, the method has the advantages of high process maturity, low process complexity, low material cost and great cost advantage.

An oxygen evolution reaction electrocatalyst and a method for preparing said oxygen evolution reaction electrocatalyst are disclosed. The method comprises the steps of contacting a porous zeolite with a solution containing a noble metal precursor to form a noble metal doped zeolite, pyrolyzing the noble metal doped zeolite to form nanocrystals comprising at least the noble metal and a second metal, said nanocrystals being confined within a layer of carbon-based material, wherein the second metal and the carbon-based material are derived from the pyrolyzed zeolite, and annealing said layer of carbon-based material confined nanocrystals to form isolated noble metal atoms singly dispersed within a metal oxide lattice of the second metal as an oxygen evolution reaction electrocatalyst.

A system and associated method and service for providing a platform that enables members to transfer, receive, or otherwise exchange cash in various international denominations and commodities, such as precious metals (e.g., gold, silver, etc.), in a mobile highly secured telecommunications environment. The system is capable of delivering cash instantly between two or more users by allowing the exchange of secure transactions between system and cash dispensing machines (ATMs). Users may pay, receive, exchange, deposit, transfer, pay bills, exchange currency, retrieve cash, deposit cash and create accounts based on the mobile phone number or a system generated code.

The invention discloses a method for leaching precious metal through catalytic oxidation of thiosulfate, which comprises the following steps: mixing a copper-containing catalytic system-thiosulfate solution with a precious metal-containing material, and carrying out leaching reaction to obtain a precious metal leachate; wherein a copper-containing catalytic system in the copper-containing catalytic system-thiosulfate solution is a copper-iminodiacetic acid complex. The precious metal is extracted by adopting a copper-iminodiacetic acid catalytic system, the leaching rate of the precious metal and the consumption of thiosulfate can be considered, the leaching effect is remarkably superior to that of an existing copper ammonia system, and industrial application is easy to achieve.

The invention discloses a method and a device for preparing CLT acid through pipeline type continuous catalytic hydrogenation reduction. According to the method, catalytic hydrogenation reduction reaction is carried out in the device. According to the method, equipment such as a five-stage static tubular mixer, a gas-liquid separation tank and a reduction liquid temporary storage tank is adopted, so that efficient hydrogenation reduction of the CLT acid nitride is realized. In the reaction process, hydrogen is proportionally introduced by stages through a grading mixer, the hydrogen pressure is controlled to be 0.8-1.0 MPa, and the reaction temperature is controlled to be 70-80 DEG C. The used platinum-carbon catalyst is not recycled and recycled after being filtered and recycled, so that the loss of precious metal platinum is effectively reduced. Through the method, the reduction efficiency of CLT acid is remarkably improved, the generation amount of byproducts and dechlorination products is low, and the nitro conversion rate reaches 99.90% or above. The method has the advantages of small equipment volume, short reaction time, high reaction stability and selectivity, and low catalyst cost.