54 results about "Oxygen reduction reaction" patented technology

This method maintains electronic conductivity and oxygen reduction reactions while suppressing the decrease in gas diffusion performance due to sintering. [Solution] An electrochemical element in which an electrode layer 2, an electrolyte layer 4, and a counter electrode layer 6 are stacked in the order described, and the air electrode or oxygen generating electrode, which is either the electrode layer 2 or the counter electrode layer 6, has an active layer 6a in which an oxidation-reduction reaction is carried out from the side of the electrolyte layer 4 and a diffusion layer 6b for diffusing gas, wherein the diffusion layer 6b is composed of a mixture of particulate LSCF and CoMn metal oxide, which is a metal oxide containing particulate Co and Mn.

The present invention relates to composite particles of a core-shell structure including a metal oxide particle core and a platinum-group transition metal shell, and an electrode for platinum-group transition metal-based electrochemical reactions including an oxygen reduction reaction, the electrode including the composite particles. Specifically, the present invention relates to: composite particles of a core-shell structure including a platinum-group transition metal shell formed on a metal oxide particle core by a photoreduction reaction; a catalyst for platinum-group transition metal-based electrochemical reactions including an oxygen reduction reaction, the catalyst including the composite particles; an electrode for platinum-group transition metal-based electrochemical reactions including an oxygen reduction reaction; a fuel cell; and a platinum-group transition metal-based electrochemical conversion device.

A high-load cobalt-based single-atom catalyst for oxygen reduction and its preparation method are disclosed, belonging to the field of electrocatalysis technology. This method utilizes the cage structure in ZnCo-ZIF to encapsulate nitrogen-rich metal molecules, followed by high-temperature carbonization under nitrogen conditions to obtain the catalyst. Benefiting from the separating effect of Zn metal nodes in ZIF and the spatial confinement effect of the ZIF cages, as well as the high nitrogen content in the guest molecule, a cobalt-based single-atom catalyst with a loading of 4.0 wt% was prepared. Furthermore, compared to traditional preparation methods, the catalyst prepared using a mixed solvent exhibits a small particle size, resulting in a high specific surface area that fully exposes the active sites. The large specific surface area allows for the full exposure of the high-load metal atom active sites, thus demonstrating excellent performance in the oxygen reduction reaction, with a half-wave potential of 0.88 V and a limiting current density of 6.0 mA·cm⁻¹ in 0.1 M KOH electrolyte. ‑2 .

The application discloses a preparation method of multifunctional composite nanometer hollow spheres, which comprises the following steps: dissolving iron cyanide in water to form solution A; dissolving cobalt salt, silver salt and sodium citrate in water to form solution B; adding solution B into solution A and stirring for 10-30 min, and then aging for 24-48 h to obtain a precursor; and heat-treating the prepared precursor in a tubular furnace under N2 atmosphere at 600-900 DEG C for 2-5 h, and the heating rate is 1-3 DEG C / min, and then continuing phosphorization treatment for 1-5 h at 300-400 DEG C by taking sodium hypophosphite as a phosphorus source to obtain multifunctional composite nanometer hollow sphere catalysts. The preparation method is simple and easy to operate, the prepared composite catalyst is composed of multiple components, has multifunctionality, and shows excellent catalytic activity on electrocatalytic hydrogen evolution, oxygen evolution and oxygen reduction reaction in an alkaline medium, and shows a good application prospect in electrocatalytic water decomposition and zinc-air batteries.

The present application belongs to the technical field of fuel cell electrocatalysts, and particularly relates to a bromine-modified iron-nitrogen-carbon oxygen reduction electrocatalyst with high iron loading and atomic dispersion, and a preparation method and application thereof. The electrocatalyst is a porous carbon-based material, and contains carbon, nitrogen, bromine and iron elements, wherein the iron is anchored in the nitrogen-doped carbon substrate in the form of atomic dispersion. The preparation method comprises the following steps: dissolving a Fe-based metal macrocycle compound in an organic solvent, mixing the organic solvent with an aqueous solution containing 2-methyl imidazole and a Br-containing precursor, and adding an aqueous solution containing a zinc salt and a surfactant for co-assembly to obtain a precursor; and pyrolyzing the precursor to obtain a bromine-modified Fe-N-C electrocatalyst. Compared with the Fe-N-C electrocatalyst without bromine modification, the electrocatalyst can effectively regulate the local coordination environment of iron sites, and has the advantages of atomic dispersion, high iron loading and excellent oxygen reduction reaction activity, and can be used in fuel cells and related electrochemical energy conversion devices.

The application belongs to the technical field of fuel cell application, and discloses a polynorbornene-based anion exchange ionomer with double-domain coupled ion channels, a preparation method and application thereof. The polynorbornene-based anion exchange ionomer simultaneously constructs an ion domain rich in cation groups and a synergistic functional domain rich in oxygen-containing functional groups at a molecular scale, the two types of domains are coupled with each other in the material and form a continuous double-domain ion transmission network, so that the ionomer can still maintain a stable and continuous hydrogen and oxygen ion transmission channel under the conditions of a thin layer state of a cathode catalyst layer and limited hydration, and effectively improves the ion transmission connectivity and catalyst utilization efficiency of the catalyst layer interface. The ionomer is suitable for being used as an ion-conducting bonding material of a cathode of an alkaline membrane fuel cell, can improve the oxygen reduction reaction performance of the cathode, and provides a new material and structural design idea for a low-noble metal loading and high-power density fuel cell electrode structure design.

The invention discloses a strong-acid-corrosion-resistant carbon-loaded platinoid all-alloy nano material and a preparation method thereof, and relates to the technical field of new energy materials. The preparation method of the carbon-loaded platinoid all-alloy nano material comprises the following steps: dispersing a carbon carrier in a solvent, adding platinum and copper precursors, dispersing, and adsorbing at constant temperature to obtain a suspension mixed solution; drying by distillation, drying and grinding to obtain a solid compound; calcining in an inert atmosphere, and cooling to obtain a carbon-supported platinoid material; and carrying out strong acid corrosion treatment, washing, drying and grinding to obtain the strong acid corrosion resistant carbon-loaded platinoid all-alloy nano material. The prepared material can keep the crystal structure stable in a strong acid environment and has excellent acid corrosion resistance, and the platinum-copper nano material takes platinum as a solvent and copper as a solute to form a complete alloy phase with the atomic ratio of copper to platinum being greater than or equal to 1: 1. When the material is used as an oxygen reduction catalyst, the atom utilization rate of platinum is high, and meanwhile, the oxygen reduction reaction catalytic activity and long-term stability of the material are remarkably improved.

The application relates to a porous carbon-coated cobalt sulfide nanosheet catalyst and a preparation method and application thereof, and belongs to the field of electrocatalytic materials and renewable energy technologies. The application constructs a composite nanosheet structure of Co9S8 nanoparticles embedded in a porous carbon matrix, so as to solve the problems of insufficient activity and stability of a bifunctional oxygen catalyst. The preparation method comprises the following steps: 1, preparing hexagonal alpha-Co(OH)2 nanosheets; 2, preparing a uniformly dispersed alpha-Co(OH)2 nanosheet loaded surfactant micelle template solution; 3, preparing a mesoporous melamine resin coated alpha-Co(OH)2 nanosheet composite; and 4, placing the mesoporous melamine resin coated alpha-Co(OH)2 nanosheet composite obtained in the step 3 and a sulfur source in a tube furnace respectively, and carrying out two-step high-temperature treatment under a protective atmosphere, so that the catalyst is obtained. The catalyst shows excellent bifunctional oxygen catalytic activity in an alkaline medium: the overpotential of an oxygen evolution reaction is as low as 324 mV (10 mA cm ‑2 ), and the starting potential of an oxygen reduction reaction reaches 0.92 V.

The application discloses a kind of cathode material for low-temperature metal fuel cell and its preparation method and application, preparation nitrogen-doped carbon nanotube as carrier;Utilize the liquid phase oxidation-reduction method of potassium permanganate and manganese sulfate, and introduce cobalt nitrate to carry out one-step hydrothermal synthesis;Utilize the doping effect of cobalt ion to control product crystal phase, and synthesize the rod-shaped structure of MnOOH and CoMn2O4 Nanocomposite on carrier.The obtained cathode material is through the synergistic effect of nitrogen-doped carbon carrier and metal oxide, significantly reduce the energy barrier of low-temperature oxygen reduction reaction.The cathode material has 0.79 V half-wave potential and 5.58 mA·cm ‑2 Limit diffusion current density under-10 ℃ environment;The assembled aluminum-air battery shows 1.56 V open-circuit voltage and 9.71 mW·cm ‑2 Power density under-40 ℃ environment, can be discharged stably for 16.2 h under 2 mA·cm ‑2 Current density, better than commercial Pt / C catalyst.In cold region emergency power supply, polar scientific expedition, military equipment and other extreme low-temperature scenes have significant application value.

This invention discloses a composite lightly calcined magnesia ball, its preparation method, and an intelligent slag-splashing furnace protection method using the composite lightly calcined magnesia ball. The composite lightly calcined magnesia ball provided by this invention includes an inner core and a structural reinforcement layer covering the surface of the inner core. The raw materials for preparing the inner core include the following components by mass percentage: 40%-60% carbonaceous reducing agent, 5%-15% metallic reducing agent, 3%-8% carbon stabilizer, and the balance of binder. The raw materials for preparing the structural reinforcement layer include the following components by mass percentage: 70%-85% lightly calcined magnesia powder, 2%-5% sol, 1%-3% flux, and the balance of binder. Using the above-mentioned composite lightly calcined magnesia ball with a "core-shell" structure can achieve optimized coordination of the carbon-oxygen reduction reaction and MgO melting / precipitation in terms of timing and space, avoiding the blindness of single-material reactions, resulting in a more stable and efficient process, and significantly improving the quality of the slag-splashing layer.

The application discloses a self-driven oxygen purification battery system and application thereof, which comprises a cathode gas diffusion electrode, an ion exchange membrane, an anode oxygen evolution electrode and a dehydration dryer. The cathode chamber is filled with acidic electrolyte, and the anode chamber is filled with alkaline electrolyte. The cathode gas diffusion electrode is loaded with an acidic oxygen reduction catalyst for selectively catalyzing the oxygen reduction reaction from air containing nitrogen, carbon dioxide and oxygen; and the anode oxygen evolution electrode is loaded with a non-noble metal oxygen evolution catalyst for catalyzing the oxidation of hydroxyl ions to generate oxygen. The application utilizes the ion concentration difference formed by the acid / alkali double electrolyte as a driving force, and the theoretical open circuit voltage can reach pH*0.059 V. The system can purify oxygen in air to a purity of more than 99% while spontaneously generating electricity, and the acidic environment on the cathode side effectively avoids the interference of carbon dioxide in air. The system has great application prospects in the fields of medical oxygen supply, deep-sea diving, highland operation and the like.

This invention belongs to the field of electrocatalytic materials technology, and relates to a nitrogen-sulfur co-doped mesoporous carbon catalyst, its preparation method, and its application. The catalyst is a nitrogen-sulfur co-doped carbon-based material, obtained by self-assembly and high-temperature carbonization using F127 as a template agent and m-aminothiophenol as a precursor. The catalyst possesses abundant active sites, optimized electronic structure, and mesoporous morphology, exhibiting high activity, high selectivity, and excellent stability in the electrocatalytic oxygen reduction reaction, making it suitable for efficient and environmentally friendly electrosynthesis of hydrogen peroxide.

The application provides a thiourea-modified carbon carrier loaded platinum-cobalt solid solution catalyst and a preparation method and application thereof, and relates to the technical field of catalyst preparation. First, a commercial carbon carrier is subjected to acid pickling treatment; then the acid-pickled carbon carrier is subjected to impregnation treatment in an organic solvent in which thiourea compounds are dispersed; finally, a platinum-cobalt solid solution catalyst is formed in situ on the carbon carrier by combining one-step solvothermal reduction. The catalyst exhibits excellent catalytic performance in electrocatalytic oxygen reduction reaction. The preparation method has a simple overall process, uses low-cost reagents, has low requirements on production equipment, and is suitable for large-scale batch production.

The application discloses a method for synthesizing hydrogen peroxide by electric filtration of carbon nanotube woven membrane. The method comprises the following steps: S1. dispersing carbon nanotubes without chemical catalytic modification in a solvent, and ultrasonic treatment to obtain a dispersion liquid; S2. placing the dispersion liquid on a microporous filter membrane, under the driving of pressure, the carbon nanotubes are spontaneously interwoven, physically overlapped and layer-by-layer interlocked on the surface of the microporous filter membrane under the guidance of hydrodynamic orientation, in-situ assembling a three-dimensional network structure of the carbon nanotubes to obtain a carbon nanotube woven membrane; S3. after washing and drying the carbon nanotube woven membrane, the carbon nanotube woven membrane is assembled as a cathode in a cathode chamber of an electrolytic cell, and the edge of the carbon nanotube woven membrane is sealed; and S4. connecting a circuit between the parallel placed cathode and anode, pumping an electrolyte containing dissolved oxygen into the electrolytic cell, and generating hydrogen peroxide through a two-electron oxygen reduction reaction after the electrolyte flows through the anode and vertically penetrates the nanoscale interwoven pore channels in the interior of the cathode.

The application provides a carbon-based transition metal nanoparticle and single-atom synergistic electrocatalyst, a preparation method, application and a zinc-air battery, and belongs to the technical field of electrocatalysis and metal-air batteries. In the application, through the competitive anchoring and limited action of a nitrogen-containing metal chelating agent and a nitrogen-rich precursor on metal atoms in a pyrolysis process, in-situ construction and stable coexistence of transition metal nanoparticles and single atoms are realized in one step, a single-atom-nanoparticle synergistic structure is formed, the single-atom sites dominate the efficient oxygen reduction reaction, and the nanoparticle sites dominate the efficient oxygen evolution reaction. The method has the advantages of simple process, good repeatability, easy scaling from a kilogram to a kilogram, and consistent catalyst structure performance after scaling. The membrane electrode and the zinc-air battery based on the catalyst show excellent bifunctional catalytic activity, high power density and long cycle stability, and provide a complete technical solution from materials to devices for the commercialization of high-performance and low-cost zinc-air batteries.

This invention discloses an oxygen reduction reaction catalyst, its preparation, and its application. The catalyst comprises a layered structure formed by an array of hollow carbon nanocages loaded with p-doped metal single atoms. The preparation method involves: dissolving a zinc salt and a second metal salt in water to obtain a metal source solution; mixing the metal source solution with an aqueous solution of 2-methylimidazole to obtain metal-organic framework nanoparticles; dispersing the metal-organic framework nanoparticles and a phosphorus-containing etchant capable of thermally decomposing to generate ammonia in water to form a mixed colloidal solution; freeze-drying the mixed colloidal solution to obtain a layered precursor; and calcining the layered precursor to obtain the oxygen reduction reaction catalyst. This catalyst can be applied to electrochemical oxygen reduction testing and the preparation of proton exchange membrane fuel cells and zinc-air batteries. The catalyst prepared by this invention exhibits good mass transfer performance and a high specific surface area, significantly improving the accessibility of active sites and possessing excellent electrocatalytic performance.

This invention discloses a carbon material and a cobalt atom composite catalyst, its preparation method, and its application, belonging to the field of chemical material preparation technology. First, waste rubber powder is pretreated at low temperature under an inert atmosphere, mixed with an equal mass of activator, and then activated at high temperature. After acid washing, water washing, and drying, waste rubber-derived carbon is obtained. Then, this derived carbon is mixed with a carbon-based conductive material, combined with a cobalt complex, and subjected to liquid-phase ultrasonic dispersion and solvent evaporation. Finally, the composite catalyst is obtained by heat preservation under argon protection. This invention adopts a "composite matrix + molecular anchoring" strategy, utilizing the carbon-based conductive material to optimize the carrier porosity and conductivity, and using the spatial confinement effect of the cobalt complex to inhibit metal aggregation, forming high-density Co-N-C active sites in situ. It possesses both low cost and high catalytic activity, and can be effectively applied to the oxygen reduction reaction in fuel cells, possessing both solid waste resource utilization and energy catalysis value.

This invention provides a FeMnO3 composite material, an iron-based molten salt battery, and a method for preparing the same. The method includes: the FeMnO3 composite material can be used as an active additive in an iron-based molten salt battery; the preparation method includes the following steps: adding a manganese source and an iron source to water and mixing to obtain a first mixed solution; adding a cationic surfactant and an alkaline regulator to water and mixing to obtain a second mixed solution; adding the second mixed solution to the first mixed solution and mixing; and then sequentially undergoing hydrothermal reaction, washing, drying, and calcination to obtain the FeMnO3 composite material. When applied to an iron-based molten salt battery, this composite material exhibits excellent stability and durability, cycling more than 650 times in a molten salt electrolyte at 300°C, with approximately 200 cycles achieving a coulombic efficiency higher than 80%. Simultaneously, the material possesses excellent dual-function catalytic activity for both oxygen evolution reaction and oxygen reduction reaction, exhibiting low discharge polarization, good rate performance, and high battery capacity retention.

The application discloses an olefin-connected pyridyl covalent organic framework material and a preparation method and application thereof, and belongs to the technical field of photocatalysis. The material is formed by olefin bridging of 2,4,6-trimethyl-1,3,5-triazine monomers and aromatic aldehyde monomers containing pyridine units and bipyridine units, and 2,4,6-trimethyl-1,3,5-triazine, pyridine-2,5-dimethyl formaldehyde or 2,2'-bipyridine-5,5'-dimethyl formaldehyde are heated and reacted under sealed conditions; after the reaction is completed, natural cooling to room temperature is carried out, vacuum filtration is carried out and filter residues are collected, washing is carried out, and vacuum drying is carried out, and the material is obtained. The pyridine and bipyridine units are used for constructing different oxygen adsorption modes of Pauling type and Yeager type respectively, the oxygen reduction reaction path is changed, a two-step single electron path and a one-step two electron path are realized, the photocatalytic efficiency is effectively improved, and the material has a wide application prospect as a photocatalyst for photocatalytic oxygen reduction and synthesis of hydrogen peroxide.

The application discloses an intercalated cobaltporphyrin-based COFs material, a synthesis method thereof and application of the material in electrocatalytic oxygen reduction, and the material is prepared by subjecting 5,10,15-tri (4-aldehyde phenyl) cobalt (III) porphyrin with an axial ligand pyrazine or bipyridine to a Shiff-Base reaction with p-phenylenediamine, thereby forming a COFs structure extending along a z-axis direction. The axial ligand is inserted into an interlayer through a coordination bond, replaces traditional pi-pi interaction, effectively opens an x-y space in the interlayer, increases exposure of active sites and constructs a new guest molecule transmission channel. The COFs material has excellent chemical stability and electrocatalytic stability, a relatively high specific surface area and a clear coordination environment, and exhibits higher activity, selectivity and stability in an electrocatalytic oxygen reduction reaction, with a half-wave potential being up to 0.94 V (vs. RHE), an electron transfer number being close to 3.84 and a current retention rate being 97% after 10 hours, thereby providing a new idea for design of high-performance electrocatalytic materials.

This invention discloses a high-throughput screening and construction method for intermetallic compound Pt3M alloy catalysts, and their applications. The Pt3M alloy catalyst includes a support and an active component supported on the support; the support is a nitrogen-doped activated carbon support; the active component is chemically ordered Pt3M alloy nanoparticles. This invention also discloses the preparation method and applications of the Pt3M alloy catalyst. The active component of the Pt3M alloy catalyst of this invention contains chemically ordered Pt3M alloy nanoparticles, which greatly improves atom utilization compared to traditional catalysts, achieving a reduction in the amount of precious metal. The catalyst synthesized by this invention has a relatively high active metal content and relatively good stability, exhibiting excellent oxygen reduction reaction catalytic activity. The preparation method of this catalyst is simple and easy to synthesize, with uniform dispersion of the active metal Pt, significantly reducing labor costs, and is easy to scale up, showing promise for gram-scale catalyst preparation.

This invention discloses a zirconium-iron bimetallic doped cobalt tetroxide material and its preparation method, wherein the atomic ratio of zirconium to iron in the material is 1~5:1, and Zr 4+ Co is occupied in spinel Co3O4 through lattice substitution. 3+ Dominant octahedral sites (Oh sites), Fe 3+ Occupy Co 2+ The dominant tetrahedral sites (Td sites) are present. The preparation method of the zirconium-iron bimetallic doped cobalt tetroxide electrocatalytic material includes: adding a cobalt source, a zirconium source, and an iron source to an organic solvent, mixing them uniformly, and then performing a molding process to obtain a precursor; the molding process is one of the following: hydrothermal method, solvothermal method, sol-gel method, coprecipitation method, spray drying granulation method, electrospinning method, freeze-drying method, or ball milling method; finally, the material is obtained after drying and calcination. This invention features a simple and streamlined preparation process with low equipment requirements, making it easy for industrial-scale production. The obtained transition metal oxide material does not require the addition of an additional conductive agent and can be directly used as a catalyst for electrocatalytic oxygen reduction reactions, exhibiting excellent electrochemical performance and demonstrating high selectivity and high yield in two-electron oxygen reduction tests.

The application belongs to the field of glucose detection, and particularly relates to an enzyme-free glucose sensor based on a hydrophobic substrate and a preparation method and application thereof. The application can realize glucose detection in various pH solution environments, reduces the dependence on high OH ‑ concentration of a solution; and the oxygen reduction reaction can be carried out at a lower reduction potential, which provides convenience for low-energy consumption use of the sensor.

The application belongs to the technical field of catalyst preparation, and provides a high-loading cobalt monatomic transition metal-based composite catalyst, a preparation method thereof and oxygen reduction application. ZIF material of the application is converted into nitrogen-phosphorus co-doped porous carbon through pyrolysis reaction combined with triphenylphosphine, the porous carbon is used as a carrier, and monatomic cobalt, cobalt nanoparticles, molybdenum species (MoC) and cobalt species (Co9S8) generated by pyrolysis are limited in the porous carbon. The nitrogen-phosphorus co-doped porous carbon can improve the conductivity of the catalyst, and the existence of phosphorus and nitrogen elements provides a stable environment for metal monatomic atoms, so that the catalyst has high metal loading while maintaining the monatomic structure. At the same time, Co9S8 generated by cobalt sulfide increases the metallicity of the catalyst, further provides rich catalytic active sites for the catalyst, so that the catalyst exhibits excellent performance in the oxygen reduction reaction, and the half-wave potential can reach 0.94 V, which is 90 mV higher than that of the Pt / C-based catalyst.

The application discloses a bifunctional electrocatalyst of N and P co-doped porous carbon nanosheet loaded FeCo hollow nanospheres and a preparation method and application thereof. The preparation method is as follows: nitrogen-doped carbon materials are prepared through grinding and mixing and high-temperature pyrolysis. Pluronic F-127, the nitrogen-doped carbon materials, iron nitrate, cobalt nitrate, melamine and o-phenylenediamine are added into an ethanol solution to be mixed, ultrasonically treated and stirred, and after reaction, the solution is evaporated, high-temperature pyrolysis and sodium hypophosphite phosphorization are carried out, and finally the bifunctional electrocatalyst of N and P co-doped porous carbon nanosheet loaded FeCo hollow nanospheres is obtained. The catalyst can exhibit excellent catalytic activity in electrocatalytic oxygen reduction reaction and oxygen evolution reaction, and can be applied in a liquid zinc-air battery.

Oxygen electrodes, production methods and reversible, alkaline or anion exchange membrane (AEM) electrochemical devices are provided. The oxygen electrodes are operable in the reversible devices both as cathodes of a fuel cell supporting an oxygen reduction reaction (ORR), and as anodes of an electrolyzer supporting an oxygen evolution reaction (OER). The oxygen electrodes comprise a substrate layer which may be a porous transport layer (PTL), possibly coated and / or hydrophobized, or a membrane; and a blend of catalysts which is deposited on the substrate layer to form a catalyst layer, and includes ORR catalyst (e.g., a platinum group metal), OER catalyst (e.g., nickel-based particles), and possibly binders such as ionomers, PTFE or other polymers that are resistant in alkaline environment, but with the catalyst layer and the substrate layer being devoid of elemental carbon.

The application relates to a bridged Fe-Cu bimetal carbon nanocage oxygen reduction reaction electrocatalyst as well as a preparation method and application thereof. The bridged Fe-Cu bimetal carbon nanocage oxygen reduction reaction electrocatalyst has a connected multi-level hole nanocage formed by a zeolitic imidazole metal covalent organic framework and Fe / Cu bimetal atoms bridged in the connected multi-level hole nanocage structure; wherein the Fe / Cu bimetal atoms have a bridged diatomic configuration, and are preferably N4Fe-CuN4 structures; wherein the electronic state of the Cu atom is Cu + , and the electronic state of the Fe atom is Fe 3+ .

This invention belongs to the field of electrocatalytic materials technology, disclosing a Ni-assisted electronic structure-controlled Fe-based single-atom oxygen reduction catalytic material, its preparation method, and its applications. The catalytic material uses nitrogen-doped porous carbon as a support, constructing a FeNiN6 cooperative coordination structure formed by bridging nitrogen atoms of Fe and Ni as active sites, wherein there is no direct metallic bond between Fe and Ni. This structure can regulate the electronic state of the Fe center, optimizing the adsorption behavior of intermediates during the oxygen reduction reaction, thereby improving catalytic kinetics. This invention also provides a preparation method for this catalytic material, which is simple and reproducible. The obtained catalytic material exhibits good oxygen reduction activity in both alkaline and acidic media, and demonstrates excellent output performance and cycle stability in zinc-air batteries. This invention provides a new structural design concept for improving the performance of single-atom catalysts and has promising application prospects.

The invention discloses a ZIS / CdS heterojunction photocatalyst as well as a preparation method and application thereof, and belongs to the technical field of photocatalysts. The Zn2In2S5 / CdS composite material is used as a photocatalyst to be applied to photocatalytic production of hydrogen peroxide (H2O2), and the catalytic rate of the Zn2In2S5 / CdS composite material can reach 19002 mu M.h <-1 >. G <-1 >. The material is prepared by a two-step hydrothermal method: firstly performing hydrothermal synthesis on Zn2In2S5 nanoflower, then taking the Zn2In2S5 nanoflower as a substrate, adding a cadmium source and a sulfur source, and performing a second hydrothermal reaction, so that CdS nanoparticles grow on the surface of the Zn2In2S5 nanoflower in situ, and constructing the S-type heterojunction. The S-type heterojunction constructed by the invention not only effectively promotes the spatial separation and transmission of photon-generated carriers, but also retains the high oxidation-reduction ability of the material. A performance test for producing H2O2 through photocatalysis shows that the H2O2 yield of the Zn2In2S5 / CdS composite material with the optimal proportion is 2.56 times of that of pure Zn2In2S5 and 1.59 times of that of pure CdS within 120 minutes. Research on reaction mechanisms shows that the efficient generation of H2O2 is promoted through the double-path synergistic effect of oxygen reduction reaction (ORR) and water oxidation reaction (WOR). The preparation process is simple, the structure is controllable, and a new photocatalyst is provided for efficient production of H2O2.

This invention discloses a method for preparing cobalt porphyrin covalently grafted onto phenolic resin and its application in electrocatalytic oxygen reduction. First, a cobalt porphyrin with a flexible alkyl chain is prepared. Then, the phenolic hydroxyl groups on the phenolic resin nucleophilically replace the bromine at the end of the flexible alkyl chain of the cobalt porphyrin, thereby covalently grafting the cobalt porphyrin onto the phenolic resin. Compared to the simple physical mixing of 5,10,15,20-tetra(pentafluorophenyl)cobalt porphyrin and phenolic resin, and the electrocatalytic oxygen reduction performance of unmodified phenolic resin, the cobalt porphyrin of this invention, due to its flexible alkyl chain, provides a higher local proton concentration for the covalently linked cobalt porphyrin with phenolic hydroxyl groups on the phenolic resin. Furthermore, during the electrocatalytic oxygen reduction process, the protons from the phenolic hydroxyl groups can act on the porphyrin metal center, accelerating the proton transfer rate and thus improving the performance of the electrocatalytic oxygen reduction reaction.