2139 results about "Active site" patented technology

The invention discloses a copper-based nano-enzyme, a preparation method thereof and application of the copper-based nano-enzyme in organophosphorus pesticide detection, and belongs to the technical field of pesticide residue detection. The copper-based nano-enzyme has a netted-like structure, a high specific surface area and many active sites, the valence state of a copper element is zero-valence Cu, Cu < + > and Cu < 2 + >, the copper-based nano-enzyme has high peroxidase-like activity and laccase-like activity, the detection limit is low, and glyphosate can be sensitively detected; and glyphosate, glufosinate-ammonium and isazofos can be well distinguished from six organophosphorus pesticides with medium concentration, and the method has high selectivity. The nano enzyme provided by the invention is prepared from ammonium citrate and copper nitrate in an N, N-dimethylformamide (DMF) solution by using a solvothermal method; the preparation process of the nano enzyme is simple.

The embodiment of the invention provides a tyrosine ammonia lyase mutant and application thereof in synthesis of p-coumaric acid. The mutant is subjected to any one of the following amino acid mutations on an amino acid sequence as shown in SEQ ID NO. 2: F497I, F497I + L248M, F497I + L248M + M4T, and L248M + F497I + M4T + V482L. According to the embodiment of the invention, an amino acid sequence as shown in SEQ ID NO. 2 is taken as a template, a key active site of the template is subjected to mutation transformation, a mutant library is constructed, and a series of mutants with remarkably improved catalytic activity and / or conversion rate are screened; the tyrosine ammonia lyase mutant provided by the embodiment of the invention can selectively catalyze L-tyrosine to generate p-coumaric acid, and has excellent yield and / or higher yield.

The invention discloses a preparation method and application of amino-modified single-benzene-ring copper-based MOFs (metal organic frameworks), and the method comprises the following steps: dropwise adding a copper nitrate monohydrate solution into a diamino terephthalic acid solution, fully stirring to react, and centrifugally washing and drying the product to obtain the amino-modified single-benzene-ring copper-based MOFs. The amino-modified single-benzene-ring copper-based MOFs are used for electrocatalytic reduction of carbon dioxide. The prepared amino-modified single-benzene-ring copper-based MOFs have unique morphology, active sites can be exposed on the inner surface and the outer surface, the accessibility of the active sites is improved, and meanwhile the reaction mass transfer capacity is enhanced.

The embodiment of the invention provides a method for obtaining a tyrosine ammonialyase mutant based on high-throughput screening, the tyrosine ammonialyase mutant and application of the tyrosine ammonialyase mutant. The mutant is subjected to any one of the following amino acid mutations on an amino acid sequence as shown in SEQ ID NO.2: A245G + A247T, and D192V + A245G + A247T. According to the embodiment of the invention, an amino acid sequence as shown in SEQ ID NO.2 is taken as a template (basis), a key active site of the template is subjected to mutation transformation, a mutant library is constructed, and a series of mutants with remarkably improved catalytic activity and / or conversion rate are screened; the tyrosine ammonia lyase mutant provided by the embodiment of the invention can selectively catalyze L-tyrosine to generate p-coumaric acid, and has excellent yield and / or higher yield, which indicates that the mutant has more significant application prospects in catalysis of L-tyrosine to generate p-coumaric acid.

The invention discloses a preparation method of metal ion liquid modified co-doped biochar and application of the metal ion liquid modified co-doped biochar in tetracycline removal, and belongs to the technical field of water pollution treatment and adsorption material preparation. The preparation method comprises the following steps: mixing a biochar precursor with a metal ion liquid containing transition metal and a heteroatom source, and carrying out high-temperature carbonization to obtain the metal ion liquid modified co-doped biochar. Multiple modification of the biochar is realized through one-time high-temperature carbonization (transition metal elements and heteroatoms are introduced into a biochar skeleton, abundant surface active sites are provided, and the specific surface area and pore volume of the biochar are improved), so that the adsorption performance of the biochar on tetracycline antibiotics is remarkably improved. The preparation method is simple in process, raw materials are easy to obtain, and the obtained metal ion liquid modified co-doped biochar has excellent adsorption performance on antibiotic pollutants such as tetracycline and is suitable for purification treatment of water polluted by antibiotics.

The invention relates to the technical field of electrocatalysis development, in particular to a Co-based two-dimensional coordination polymer electrocatalyst and a preparation method and application thereof. The chemical formula of the Co-based two-dimensional coordination polymer electrocatalyst is {[Co3 (H2O) 4 (5-CMOIA) 2]. 10H2O} n, an X-ray single crystal diffraction test shows that the coordination polymer belongs to a triclinic system and a P-1 space group, and the minimum asymmetric unit of the coordination polymer contains three Co (II) ions, two deprotonated (5-CMOIA) 3-ligands, four coordination water molecules and ten crystal water molecules. The Co-based two-dimensional coordination polymer has relatively high specific surface area and rich active sites, is good in dispersity in a solution, and can be applied to the field of electrocatalysis.

The invention relates to the technical field of mineral processing data processing, in particular to a preparation method of a high-calcium fluorite and barite paragenic ore combined inhibitor, which comprises the following steps: collecting multi-source process mineralogy data output by an X-ray fluorescence spectrometer, an automatic mineral analyzer and the like, converting the multi-source process mineralogy data into a structured format, and constructing a process mineralogy database; based on historical data of a database, a random forest algorithm is adopted to train a correlation model, the correlation rule of mineral characteristics such as calcite content, fluorite particle size distribution and barite monomer dissociation degree and the inhibitor ratio is learned, and parameters of the optimization model are fed back through a flotation test. The combined inhibitor solves the problem of selective separation caused by similar surface properties through a synergistic effect of covering active sites of fluorite calcium by modified water glass, regulating active sites of barite barium by citric acid and assisting in enhancing inhibition by modified starch, and solves the problem of low efficiency of multi-source data integration through structured data processing and model closed-loop optimization; the flotation separation efficiency and the concentrate grade are improved.

The invention discloses application of a Ni-based reverse-phase catalyst in catalytic hydrogenation reaction of a nitro compound, nitro in the nitro compound is hydrogenated to reduce amino, the Ni-based reverse-phase catalyst is of an M / Ni reverse-phase structure, metal Ni for dissociating hydrogen serves as a carrier, nano metal M oxide is loaded on the carrier to serve as a loading phase, and reverse-phase interface active sites are constructed; wherein the metal M is one or two of Ce, Zr, Al, Y and Mg, and the mole fraction of the load phase metal M is 5-50% based on the mole fraction of all the metals in the catalyst being 100%. The preparation method of the catalyst is simple and easy to implement, the catalyst has a non-traditional supported reversed-phase structure, the activity of the catalyst is more excellent than that of a traditional supported catalyst when the catalyst is applied to the nitro-compound hydrogenation process, a traditional Raney nickel catalyst can be effectively replaced, a reaction system is clean and safe, repeatability is good, effective recycling can be achieved, and the catalyst is suitable for industrial production. The method is suitable for industrial production and has a good application prospect.

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

The invention discloses a multi-component catalyst active site prediction system and method fused with quantum embedding, and relates to the technical field of catalysis and material informatics, and the system comprises a structure and site enumeration module which generates candidate sites; the adaptive quantum embedding calculation module obtains key reaction microcosmic parameters; the unified site fingerprint and feature engineering module constructs and fuses standard site fingerprints; the physical consistency machine learning module predicts adsorption energy and other parameters and uncertainty thereof; the active learning and sample selection module selects a high-value sample optimization model; the microdynamics evaluation module calculates index values such as activity; and the multi-objective optimization and sorting module generates an optimization sorting list. According to the method, the unification of calculation precision and efficiency is realized, the problem of non-unification of locus characterization is solved, the model interpretability and extrapolation reliability are improved, and the comprehensive evaluation and optimization sorting of multi-target performance are completed.

The invention discloses a hydroxyl-rich ruthenium / titanium dioxide catalyst as well as a preparation method and application thereof, and the preparation method comprises the following steps: step 1, loading a ruthenium precursor on a titanium dioxide carrier by adopting an impregnation method or a deposition-precipitation method, and drying and calcining to obtain a Ru / TiO2 catalyst; and step 2, placing the Ru / TiO2 catalyst in an atmosphere environment containing water vapor or forming a physical adsorption water film on the surface of the Ru / TiO2 catalyst, and performing ultraviolet irradiation treatment to obtain the Ru / TiO2 catalyst. According to the method, water is physically adsorbed through ultraviolet light dissociation, hydroxyl is directly generated on the surface of Ru / TiO2 in an in-situ mode, the method is easy to operate, complex liquid phase treatment is not needed, and the stability of the generated hydroxyl under the subsequent high-temperature gas-solid phase hydrogen-rich reaction condition is obviously superior to that of hydroxyl introduced through a traditional method. The stable hydroxyl enriched on the surface serves as an effective Lewis base site and cooperates with a Ru active site, adsorption and activation of CO2 molecules are remarkably promoted, and therefore the catalytic activity of the CO2 methanation reaction is greatly improved.

The invention discloses a polyphosphate kinase mutant, a biological material, a catalyst and application, and belongs to the field of protein engineering, and compared with a wild enzyme, the mutant has one or more amino acid residue mutations in the 307th site, the 311th site, the 320th site, the 408th site, the 419th site and the 431th site. The mutant disclosed by the invention is obtained by combining a semi-rational design strategy with active site region prediction and mutation library design screening, and the enzyme activity and the relative yield are remarkably improved: the efficiency of catalytic synthesis of GTP by using the preferable mutant Y431P / K311F / W408A with GMP as a substrate is 2.6 times that of a wild type enzyme, and the relative yield is improved by 150%; the efficiency of the optimized mutant Y431P / K311F / R419L for catalytically synthesizing GTP by taking GDP as a substrate is 1.9 times that of a wild enzyme, and the relative yield is increased by 82%. The key mutant obtained by screening can realize efficient synthesis from cheap NDP or NMP to high-value NTP, and has an excellent industrial application prospect.

The invention relates to the technical field of cable materials, in particular to a flame-retardant efficient cross-linked polyolefin cable body and a preparation method thereof. The cable body comprises a polyolefin matrix, 2, 4-dihydroxy-6-methyl benzamide, an intumescent flame retardant, dicumyl peroxide, an antioxidant, a light stabilizer and a lubricant, wherein the polyolefin matrix is subjected to synergistic modification by phosphorus-nitrogen heterocyclic silane-plasma. The preparation method of the polyolefin matrix synergistically modified by phosphorus-nitrogen heterocyclic silane-plasma comprises the following steps: performing grafting reaction on polyolefin resin and phosphorus-nitrogen heterocyclic silane under the action of an initiator, and performing plasma surface treatment to endow the material with dual active sites. The preparation method comprises the following steps: melting and granulating a polyolefin matrix subjected to phosphorus-nitrogen heterocyclic silane-plasma synergistic modification, small organic molecules and auxiliaries, and performing extrusion molding under a crosslinking condition to obtain a cable body. The material disclosed by the invention has comprehensive advantages in flame-retardant efficiency, crosslinking degree and mechanical property, and is suitable for manufacturing high-safety power cables.

A system and method for generating thermostable variants of a protein is disclosed. The system receives a three-dimensional structure of a target protein and identifies mutable regions, including solvent-exposed residues and loop regions. Conserved and active site residues are excluded from mutation through a fixed-position mask. A message-passing neural network (MPNN) generates mutant sequences at unmasked positions, executed under multiple temperature parameters. Design scores based on Shannon entropy and log probability are computed, and high-confidence variants are selected. Predicted structures for selected variants are evaluated using structural and sequence-based features to compute stability scores. A ranked list of thermostable variants is generated. Top candidates undergo molecular dynamics simulations to compute dynamic metrics such as RMSD, radius of gyration, SASA, and ddG, and are re-ranked accordingly. The system enables accurate, constraint-driven protein design with high structural and functional fidelity, suitable for industrial and therapeutic applications.

The invention discloses a La < 3 + >-doped lithium manganese oxide lithium ion sieve as well as a preparation method and application thereof, and belongs to the technical field of salt lake lithium extraction. The preparation method comprises the following steps: by taking Mn2O3 and LiOH as raw materials, carrying out hydrothermal reaction to generate LiMnO2, mixing the LiMnO2 with La2O3, grinding and calcining to form a La < 3 + >-doped spinel structure precursor La-LMO, and carrying out acid pickling to prepare La-HMO. La < 3 + > replaces part of Mn < 3 + >, the average valence state of manganese is improved, meanwhile, the structural stability of the manganese is enhanced through the high bond energy of La-O bonds, the number of exposed manganese atoms is reduced, manganese solution loss caused by Mn < 3 + > disproportionation reaction in the acid treatment process is effectively inhibited, the adsorbed oxygen content and active sites are increased, and the lithium ion adsorption capacity is remarkably improved. The material has high-selectivity adsorption capacity on lithium ions in salt lake brine in a strong alkaline environment, the manganese solution loss rate is obviously lower than that of traditional HMO, the cycle life is remarkably prolonged, and the industrial application potential is remarkably improved. The preparation process of the lithium ion sieve is simple, the raw material cost is low, and the technical bottlenecks that an existing manganese-based lithium ion sieve is poor in structural stability and high in manganese solution loss are solved.

The application discloses an adsorbent and a preparation method and application thereof, and belongs to the technical field of environmental adsorption materials. The adsorbent comprises biogenic diatom and halloysite nanoparticles, and the biogenic diatom is in-situ loaded with the halloysite nanoparticles. The adsorbent is used for adsorbing tetracycline antibiotics. The biogenic diatom in the adsorbent has biological capture and adsorption effects on nanoclay minerals, can uniformly load the halloysite nanoparticles on surface organic active sites, and thus can in-situ load a halloysite nanoparticle film on the surface of the diatom. The adsorbent not only well retains the macroporous structure of the diatom, but also constructs mesoporous and microporous hierarchical pore structures, can effectively improve the adsorption capacity of the adsorbent on tetracycline antibiotics, and has a wide application prospect in the fields of adsorption and pollution treatment of tetracycline antibiotics.

The invention relates to the technical field of catalyst preparation, and provides a nitrogen-containing molecule modified MXene loaded Pt monatomic catalyst, a preparation method and application, the preparation method comprises the following steps: S1, preparing an NH2 / CC electrode; s2, dipping the NH2 / CC electrode in a mixed solution of an MXene suspension and chloroplatinic acid hexahydrate at room temperature for reaction, and then irradiating and drying with a mercury lamp to obtain an NH2-MX / Pt-CC electrode; and S3, carrying out secondary amino modification to obtain the catalyst containing nitrogen molecule modified MXene to load Pt single atoms. According to the preparation method of the catalyst with the nitrogen-containing molecule modified MXene loaded with the Pt single atoms, the atom utilization rate of the material is effectively increased, reaction active sites are increased, meanwhile, the interaction between the two-dimensional material and the Pt atoms is enhanced, and the stability of the catalyst under the industrial and current density is improved.

The invention relates to the technical field of chemical catalysis, and particularly discloses a covalent organic framework material loaded bimetallic monatomic electrocatalyst and a preparation method and application thereof, the catalyst comprises a carrier and atomic-scale dispersed metal diatomic active sites; the atomic-scale dispersed metal diatomic active sites are anchored in the carrier through a simple post-impregnation method; the carrier is a triazinyl covalent organic framework; a coordination structure is formed between the atomic-scale dispersed metal diatomic active sites and the carrier through a nitrogen-metal-chlorine bridging structure; the diatom-dispersed difunctional electrocatalyst has good overall water decomposition performance, under the condition of 1M KOH, the overpotential of hydrogen evolution reaction is 39.3 mV at 10 mA cm <-2 >, the overpotential of oxygen evolution reaction is 251.2 mV at 10 mA cm <-2 >, the synthesis process is simple and easy to implement, the preparation cost is low, and the diatom-dispersed difunctional electrocatalyst has industrial production and application prospects.

The invention provides an all-silicon molecular sieve confined Pt-based bimetallic catalyst and application thereof in preparation of propylene through propane dehydrogenation. The preparation method comprises the following steps: mixing a silicon source, a template agent, a Pt precursor, an auxiliary element Cu precursor and the like by adopting an in-situ synthesis method, synthesizing under a hydrothermal condition, washing, drying, roasting and reducing to obtain the Pt-based bimetallic molecular sieve catalyst. According to the present invention, the pure silicon molecular sieve Silicalite-1 (S-1) is adopted as the carrier, such that the good carrier characteristics of high thermal stability, low acidity, rich pore structure and the like are provided, and the silicon hydroxyl group (Si-OH) in the S-1 pore channel can further provide the metal species anchoring effect so as to easily disperse and limit the active site; and the Cu auxiliary agent improves the metallicity of Pt. The synergy of the two significantly improves the performance of propylene preparation by direct dehydrogenation of propane. The synthesized PtCu-coated S-1 catalyst is low in Pt loading capacity, Pt and Cu are highly dispersed, side reactions such as deep dehydrogenation of propylene can be inhibited, and good stability is achieved.

The invention relates to a water treatment and membrane separation technology, and provides an integrated catalytic separation membrane, a preparation method thereof, and a water treatment method and system. According to the membrane, polyvinylidene fluoride is used as a continuous phase to form a porous matrix, and cerium dioxide is embedded and fixed in a mode of uniform dispersion in a membrane body in a phase inversion membrane forming process; in the presence of illumination and peroxysulfate, active species are generated through in-situ activation on a membrane-water interface, and membrane separation is completed synchronously. The water treatment method comprises the following steps: adding peroxymonosulfate or peroxydisulfate into a water body to be treated, and filtering through the membrane under illumination; the photothermal effect generated by organic matter degradation intermediates in operation inhibits membrane pollution and maintains flux. According to the invention, short-range coupling of active sites and mass transfer channels is realized, the medicament and energy utilization rate is improved, the coating stripping and metal dissolution risk is reduced, and the method is suitable for drinking water pretreatment, reclaimed water deep treatment and treatment of water containing natural organic matters / humic acid.

The invention belongs to the technical field of environmental catalytic materials and pollutant control, and particularly relates to a Ni-coated NiS < 2 >-coated MoS < x > / NF composite catalyst and a preparation method and application thereof. According to the preparation method of the Ni-coated NiS2-coated MoSx / NF composite catalyst provided by the invention, the Ni-coated NiS2-coated MoSx / NF composite catalyst with a self-supported metal / crystalline / amorphous heterojunction is constructed by virtue of a collaborative strategy of directional self-assembly and internal Ni source and water dispersion, and meanwhile, the activation efficiency of peroxymonosulfate (PMS) can be remarkably improved by combining an Ni-Mo bimetal active center, so that the activation efficiency of the Ni-coated NiS2-coated MoSx / NF composite catalyst is improved. The problems that an existing catalyst is limited in active site and poor in structural stability are solved, the excellent capacity of activating PMS to remove antibiotics is shown, therefore, efficient degradation of antibiotic pollutants is achieved, and the catalyst has wide application prospects in antibiotic wastewater treatment.

The invention provides a preparation method of a Ru-based alloyed heterojunction water electrolysis hydrogen production catalyst, and belongs to the technical field of nano materials and electrochemistry. The two-dimensional porous Ru-based alloyed heterojunction electrolytic water hydrogen production catalyst can be prepared at low cost and high efficiency in an air atmosphere by using a ternary molten salt assisted Joule heat rapid calcination process. The water electrolysis hydrogen production catalyst has excellent structure and component advantages, and the two-dimensional porous structure has the advantages that the number of active sites of the catalyst can be increased, and hydrogen can be easily removed in the reaction process. The alloying heterojunction component has the advantages that the variety of Ru active sites can be increased and the synergistic effect of different components can be stimulated by alloying and abundant heterogeneous interfaces. Furthermore, the hydrogen evolution reaction kinetics of the adsorption energy of Ru to an intermediate product is optimized, and excellent alkaline electrolytic water hydrogen evolution performance is shown.

The invention provides structures and synthesis of a class of piezoelectric monomers and COFs with fluorine-substituted side chains tethered on the peripheral position of an aromatic moiety (thus different functional side chains). The multi-fluoro groups on the mentioned piezoelectric COFs provide abundant piezoelectric active sites, which enable the application as the active layer for PENGs. The exemplary embodiments also provide a process for the fabrication of a piezoelectric COF and a process for the fabrication of the piezoelectric nanogenerator utilizing mentioned piezoelectric COF.

The invention belongs to the technical field of energy storage materials, and particularly relates to a phase change energy storage material and a preparation method thereof.The phase change energy storage material is prepared from 8-12 parts of phase change wax, 10-15 parts of ZnAl-LDH, 6-9 parts of SiC-CuS and 8 parts of polyethylene glycol dimethyl ether; according to the invention, the double-metal hydroxide and the phase-change wax are combined, interlayer water molecules and ionic bonds of the double-metal hydroxide can realize reversible phase change, the phase-change wax can be supported to reduce high-temperature flowing, the phase-change wax makes up for insufficient latent heat and improves energy storage capacity, and the combination of the double-metal hydroxide and the phase-change wax widens the phase-change temperature range and enhances cycle stability; in addition, Si-C loaded CuS nanosheets are introduced, energy can be transmitted under illumination or heat energy to assist storage, the smaller the size of the nanosheets is, the larger the specific surface area is, more active sites can be provided, the heat conduction efficiency is improved, complementation of all advantages of the material is achieved through a simple method, and good comprehensive performance is achieved.

The invention provides a covalent organic framework material as well as a preparation method and application thereof, 1, 3, 6, 8-tetra (4-aminophenyl) pyrene is selected as a central construction unit, and a trap state is realized in a covalent organic framework (COFs) by regulating and controlling the symmetry of active sites (benzothiadiazole, BT). Compared with a centrosymmetric counterpart in the COFs, by breaking the symmetry of the center BT core, the trap state density in the COFs can be remarkably reduced, and the service life of the shallow trap state can be prolonged to 1160.02 picoseconds. Therefore, more photo-induced electrons can participate in the photocatalytic reaction, and the remarkable performance (greater than 99%) of photocatalytic reduction of uranium (VI) is finally realized. According to the invention, the key effect of symmetric breaking in inhibition of excited state decay of COFs is clarified for the first time, and a profound solution is provided for understanding how to improve the photocatalytic performance of COFs in environmental restoration.

The invention relates to the technical field of catalytic materials, in particular to a molybdenum sulfide-based electro-catalytic material and a preparation method and application thereof. The invention provides a molybdenum sulfide-based electro-catalytic material, which comprises a transition metal chalcogenide containing chalcogen element vacancies and titanium dioxide quantum dots containing oxygen vacancies compounded on the surface of the transition metal chalcogenide, and a composite interface of the transition metal chalcogenide and the titanium dioxide quantum dots has a heterojunction structure. According to the composite electrocatalytic hydrogen evolution catalyst containing the TiO2 quantum dots and coupled with the double vacancies and the preparation method of the composite electrocatalytic hydrogen evolution catalyst, through the quantum effect and the double vacancy defect effect of the TiO2 quantum dots, the conductivity and the active site density of transition metal chalcogenide catalysts are improved, and the electrocatalytic hydrogen evolution performance is synergistically enhanced.

The invention provides a low-molecular soluble chelating collector as well as a preparation method and application thereof, and belongs to the technical field of mineral processing. According to the collecting agent, low-molecular-weight ethylene glycol terephthalate serves as a precursor, and isosorbide is introduced for a copolymerization reaction; glutamic acid is introduced as a branched chain unit, and the branching degree and reaction active site density of the molecular structure are remarkably improved by utilizing the polyfunctional group characteristic of glutamic acid. A rigid ring structure and an ether bond of the isosorbide endow the medicament with good water solubility and dispersity, and invalid curling of a macromolecular chain is avoided; the introduction of glutamic acid branched chains greatly increases the number of hydroxyl groups and amino groups capable of reacting with carbon disulfide, so that each molecule carries more xanthate groups, and the adsorption stability and coverage density of the molecule on the surface of arsenopyrite are enhanced. By means of the structure, xanthate functional groups are fully exposed, multi-tooth chelation is easily conducted on the xanthate functional groups and iron and arsenic ions on the surface of arsenopyrite, a strong hydrophobic surface layer is formed, and therefore the collecting selectivity is remarkably improved.

The invention discloses a two-dimensional Pd nanosheet electrocatalyst rich in grain boundary and a preparation method of the two-dimensional Pd nanosheet electrocatalyst, and belongs to the technical field of electrochemical catalysis. The method comprises the following steps: by taking palladium acetylacetonate as a precursor, ascorbic acid and carbon monoxide as reducing agents and oleylamine as a solvent, carrying out heating reaction in a high-temperature reaction kettle; after the reaction is completed, the obtained mixture is cleaned and dried, and finally the ultrathin two-dimensional Pd nanosheet rich in the grain boundary is prepared. According to the preparation method, the active sites of the basal plane can be greatly increased, the electronic structure of the catalyst can be optimized, the catalytic performance and the quality activity can be effectively improved, and the synthesized two-dimensional Pd nanosheet rich in the grain boundary can be used for a fuel cell, a metal-air battery and an efficient electrocatalyst in the electrochemical oxygen reduction process.

The invention belongs to the field of fuel cells, and particularly relates to an electrode material for a fuel cell and a preparation method thereof, and the preparation method comprises the following steps: preparing polyimide containing amino POSS (Polyhedral Oligomeric Silsesquioxane); carrying out primary pyrolysis, and sequentially carrying out acid etching, cleaning and drying on a product to obtain primary carbonized polyimide; and grinding the primary carbonized polyimide, performing pyrolysis again, and sequentially performing acid etching, cleaning and drying on the product to obtain the electrode material for the fuel cell. The electrode material has a good graphite structure and a rich pore structure, so that ions and electrons can be quickly transferred in pores while the good conductivity of the material can be ensured; meanwhile, introduction of non-metal nitrogen heteroatoms can increase active sites, the electrochemical activity of the material is remarkably improved, and the material is suitable for being used as an electrode material of a fuel cell.

The invention discloses a preparation method of a Prussian blue analogue (CoFe-PBA) and copper metal organic framework (HKUST-1) composite core-shell material and application of the composite core-shell material in oxygen evolution reaction (OER). The material is prepared through a step-by-step synthesis and composite process: firstly, synthesizing copper-based MOF (HKUST-1) and a ferrocobalt Prussian blue analogue (CoFe-PBA), then compounding the copper-based MOF (HKUST-1) and the ferrocobalt Prussian blue analogue (CoFe-PBA) through a solvothermal method to form a core-shell structure (HKUST-1-atCoFe-PBA), and further performing high-temperature oxidation and vulcanization treatment to obtain HKUST-1-atCoFe-O and HKUST-1-atCoFe-S materials. According to the composite material, the electron transmission efficiency and the catalytic activity are remarkably improved by utilizing the synergistic effect of multi-metal active sites of Cu, Co and Fe. No precious metal or strong corrosive reagent is used in the preparation process, the cost is low, and the green synthesis requirement is met. An electrochemical test shows that the OER overpotential of the optimized catalyst at the current density of 10mAcm is only 268mV, and the catalyst shows excellent catalytic performance. The material can be widely applied to the fields of water electrolysis hydrogen production and the like, and has important industrial application prospects.