103results about How to "Increased oxygen reduction activity" patented technology

The invention discloses a nitrogen-doped carbon nano-material, a preparation method of the nitrogen-doped carbon nano-material and an application of the nitrogen-doped carbon nano-material to preparation of a negative electrode material of a fuel cell. The nitrogen-doped carbon nano-material is prepared from the components of nitrogen-containing heterocyclic compounds and a carbon nano-material, wherein the mass content of nitrogen is 2-10.4 percent. The preparation method comprises the steps of (1) uniformly mixing the surface-active carbon nano-material and a nitrogen-containing complex according to the mass proportion of 1 to (1-5), thus obtaining a precursor mixture; and (2) under the protective gas environment, raising the temperature of the precursor mixture obtained in the first step to 800-1,000 DEG C, and calcining for 2-40 hours. The nitrogen-doped carbon nano-material provided by the invention shows preferable oxygen reduction catalysis performance; the preparation method provided by the invention can be applied to various carbon nano-materials and is good in the adaptation; with the adoption of the preparation method, the whole preparation process is simple and easy to operate and is suitable and low in the cost.

The invention provides a preparation method of N-P-codoping porous biomass carbon catalyst. Cheap and easy-to-get biomass chitosan is taken as carbon source and nitrogen source (as nitrogen-containing ligand at the same time), organic phosphorus compound triphenylphosphine is taken as phosphorus-containing ligand, the nitrogen-containing ligand and the phosphorus-containing ligand form a coordination compound together with metal ions in metallic salt solution, ZnCl2 is taken as activating agent, the coordination compound is subjected to high-temperature pyrolysis in a nitrogen atmosphere to form holes, and finally diluted hydrochloric acid is used to remove metals for secondary hole formation, so as to prepare the N-P-codoping porous biomass carbon catalyst with rich micropores and a mesopores structure as well as a high specific surface area. The N-P-codoping porous biomass carbon catalyst is comparable to commercial Pt/C (20%) in catalytic performance in an alkaline environment, has good methanol poisoning resistance and stability, and can regulate components and performance of catalyst in molecular level. The N-P-codoping porous biomass carbon catalyst disclosed by the invention is expected to replace cathode oxygen reduction catalyst of the commercial Pt/C, and has a very good industrial application prospect.

Disclosed is a non-noble metal catalyst for oxygen reduction. The catalyst comprises a flake-like graphene carrier; a nitrogen-doped carbon skeleton arranged between neighbor flake layers of the flake-like graphene carrier; the graphene flake layers are separated by the nitrogen-doped carbon skeleton; and nanometer particles are adhered to the flake layers of graphene. The nanometer particles are one or more than two of carbon-coated non-noble metal particles, carbon-coated non-noble metal carbide particles, and carbon-coated non-noble metal nitride particles. A preparation method of the non-noble metal catalyst for oxygen reduction comprises: adding graphite oxide and non-noble metal precursor salt into water; performing mixing and standing; adding nitrogen-containing micro-molecules, a Nafion solution, and an oxidizing agent; performing uniform mixing; allowing the obtained solution to be evaporated; performing freeze-drying; and performing temperature programming thermal treatment and other after-treatment to obtain the non-noble metal catalyst for oxygen reduction. The catalyst has advantages of high oxygen reduction activity, good mass transfer performance, and low price.

The invention discloses preparation method for nitrogen-doped porous carbon supported non-noble metal electrocatalyst. According to the method, magnesium oxide is taken as a hard template; mixture containing nitrogen ligands and polyacid is taken as a nitrogen source and a carbon source; mixture dispersion is carried out through an ultrasonic rotary evaporation method; carbonization is carried out through high temperature roasting; the template is removed through utilization of acid solution, thereby obtaining a porous carbon material; a non-noble metal macrocyclic compound and the porous carbon material are mixed through the rotary evaporation method; and the supported non-noble metal electrocatalyst is prepared through heat treatment and acid-washing. According to the method, the nitrogen-doped porous carbon material with a high specific surface area is taken as a carrier, thereby facilitating the dispersion of the metal-nitrogen/carbon in the non-noble metal macrocyclic compound and the mutual coordination effect between the carrier and the metal-nitrogen/carbon active site, so the oxygen reduction activity of the catalyst is greatly improved. The material has relatively high electrocatalytic activity for the oxygen reduction of a cathode of a fuel cell, the material has a potential application prospect and the commercial application process of the fuel cell is promoted.

The invention discloses a catalyst using a metal oxide as a carrier for fuel cells and application thereof. The catalyst is characterized in that: the metal oxide as the carrier has catalytic oxygen evolution function simultaneously, and a noble metal with catalytic oxygen reduction function is supported on the metal oxide; the nanoparticles of the noble metal are highly dispersed on the surface of the metal oxide as the carrier, wherein the mass fraction of the noble metal is 2 to 70 percent in the catalyst. The catalyst alone or the catalyst mixed with platinum black in a certain proportionis applied to bifunctional oxygen electrodes for utilized regenerative fuel cells. Compared with the traditional mechanical mixture of platinum black and an oxide from catalytic oxygen evolution reaction, the fuel cell and water electrolysis performances of the cells are greatly improved, and the performance is close to that of a commercial Pt / C catalyst in fuel cells. The catalyst is applied to fuel cell oxygen electrodes to effectively solve the problems that the activity of the catalyst is deceased by the corrosion of the carrier.

The invention provides a preparation method and application of a graphene-supported non-noble metal electrocatalyst. The method comprises the following concrete steps: under a heating condition, mixing a nitrogen-containing ligand with a metal salt to form a complex; depositing the complex on a graphene supporter through cooling; adding a reducing agent to reduce oxidized graphene; and carrying out washing, drying, heat treatment and pickling so as to obtain the graphene-supported non-noble metal electrocatalyst. The graphene-supported non-noble metal electrocatalyst prepared in the invention is such structured that particles with a size of 2 to 200 nm supports or coats reduced oxidized graphene. Under an alkaline condition, the onset potential of the non-noble metal electrocatalyst in an oxygen reduction reaction is positively shifted by 35 mV compared with that of a 20 wt% commercial platinum/carbon electrocatalyst, and durability and methanol poisoning resistance of the non-noble metal electrocatalyst are better than those of the 20 wt% commercial platinum/carbon electrocatalyst. The graphene-supported non-noble metal electrocatalyst can be applied to proton exchange membrane fuel cells.

The invention provides a method for an anchoring platinum catalyst of a transition metal on a carbon nanotube, which pertains to the technical field of fuel cells. The method purifies the carbon nanotube sold on a market by concentrated nitric acid and uses mixed acid of hydrogen peroxide and the concentrated nitric acid for treatment to obtain the functionalized carbon nanotube. And then the functionalized carbon nanotube, partial platinum salt and all transition metal M salt are stirred and reflow for certain time, added with rest platinum salt to continue to reflow, cooled, washed centrifugally, dried and carried out heating treatment in a hydrogen atmosphere, thus obtaining the anchoring platinum catalyst of the transition metal on the carbon nanotube. The anchoring platinum catalyst of the transition metal on the carbon nanotube prepared by the invention has extremely good stability and the catalytic activation of oxygen reduction and can substitute kindred commercialized catalysts.

The invention discloses a monatomic iron-based carbon material and a preparation method and electrocatalytic application thereof. The preparation method includes dissolving ammonium iron acetate powder of certain mass in deionized water of specific volume, adding zeolite imidazole framework structural material ZIF-7, stirring violently for 4-24 hours, washing centrifugally, and drying to obtain yellow solid powder; placing the yellow solid powder of certain mass into a quartz boat, and placing the quartz boat into a horizontal tubular furnace with a quartz tube; heating to 600-1100 DEG C in aninert atmosphere, holding the temperature for 2-12 hours, and cooling naturally to room temperature; treating with an acid solution at the temperature of less than 90 DEG C for 8-25 hours, filtering,washing with water, and drying to obtain the monatomic iron-based carbon material. a precursor used herein has a wide range of origins; the preparation process is simple; batched macroscopic preparation can be carried out.

The invention discloses a high-activity methanol-resistance direct methanol fuel cell cathode catalyst and a preparation method thereof. The activity composition of the catalyst is Cu/PtM, the carrier is a carbon nanotube, wherein, PtM is used for improving oxygen reduction activation and Cu is used for improving methanol-resistance performance. The preparation method is as follows: firstly, the carbon nanotube, the compounds of metal M, and platinic chloride solution are scattered in glycol ultrasonically, the pH value is adjusted, the temperature is increased and reflux is carried out, platinum based catalyst loaded by the carbon nanotube is prepared by filtering, washing and drying; then the prepared platinum based catalyst loaded by the carbon nanotube is scattered in the glycol and is added with copper sulfate, then the pH value is adjusted, the temperature is increased and the reflux is carried out, and then the platinum direct methanol fuel cell cathode catalyst loaded by the carbon nanotube coated with Cu is prepared by the filtering, washing and drying. The preparation method is simple, operational condition is mild and the controllability is good; besides, the catalyst prepared by the method has high oxygen reduction activation and good methanol-resistance performance.

The invention discloses a preparation method of three-dimensional hierarchical porous nitrogen-doped graphene and the product, and belongs to the field of graphene preparation.The preparation method comprises the steps that a biomass material which is most common in the natural world is selected as a raw material and taken as a solid carbon source, a nitrogen source and a synthesizing template simultaneously, gradient dewatering processing is firstly performed, then carbonization and pre-expansion processing is performed, the processed biomass material is mixed with a K2CO3 solution, high-temperature activation is performed, freeze-drying is performed, and then the three-dimensional hierarchical porous nitrogen-doped graphene is obtained.The obtained graphene has a hierarchical pore structure comprising macropores, mesopores and micropores, the nitrogen-doped content is 2.5 at.%-7.5 at.%, and the specific surface area reaches up to 1300 m<2>/g or above.The preparation method has the advantages that the preparation technology is simple and the prepared graphene is excellent in performance and shows the very good oxygen reduction activity in the electro-catalysis field.

The invention relates to high-performance and intermediate- and low-temperature composite positive electrode material with a pomegranate fruit structure for a solid-oxide fuel cell. The composite positive electrode is particularly an LSCF-GDC & YSZ nanometer composite positive electrode in which an LSCF-GDC pomegranate seed layer is attached onto an YSZ framework diaphragm, wherein the size of pomegranate seed LSCF-GDC particle is 10-20 nanometers, and the YSZ diaphragm is formed by connecting particles of around 200 nanometers. The positive electrode with such structure has a relatively long three-phase boundary, and the YSZ diaphragm is grown with an electrolyte membrane after high-temperature sintering to form a smooth ionic conductive passage; and moreover, with the addition of GDC in the LSCF-GDC nanometer composite particle, Sr is prevented from being enriched in an LSCF surface, thus, the generation of a high-resistance phase SrZrO<3> is prevented, and the performance and the stability of the electrode are remarkably improved.

The invention provides a preparation method of a proton-exchanging membrane fuel-cell catalyst composite carrier, which comprises the following steps of: mixing a carrier base material with a heteropoly-acid solution, and filtering after uniformly mixing to obtain the carrier base material dipped with heteropoly acid; and firing the carrier base material dipped with the heteropoly acid in an inert atmosphere to obtain the proton-exchanging membrane fuel-cell catalyst composite carrier. The catalytic efficiency of a catalyst can be improved through the composite carrier prepared by the preparation method provided by the invention. In addition, the preparation method provided by the invention has the advantages of simpleness and easiness in operation, controllable preparation process condition, energy saving and environmental protection.

The invention belongs to the field of electrochemistry catalysis, and discloses a preparation method of an atomic dispersion non-noble metal fuel battery cathode catalyst. The method comprises the following steps: (a) heating and dissolving alginate into an alginate solution, keeping a heating temperature, adding metal salts into the alginate solution, and generating an alginate chelate solution; (b) adding organic nitride into the alginate chelate solution, enabling the organic nitride and the alginate chelate solution to react, and drying a product after reaction by steaming to obtain a powdered compound; and (c) successively performing primary heat treatment, acid pickling and secondary heat treatment on the powdered compound, thus obtaining the needed catalyst. By virtue of the preparation method, the catalyst with high activity in an acid medium is prepared, and active sites are uniformly dispersed and fixed, so that the preparation method is easy in control and regulation and suitable for large-scale production and application.

The invention discloses a Pt-M metal alloy catalyst prepared by electro-deposition in an organic system. A catalyst conductive carrier is carbon-based, and in an organic solvent, Pt-M metal alloy nanoparticles prepared by co-deposition of Pt-M metal are uniformly dispersed on a surface of the carrier by a physical loading mode; during the preparation process, a Pt source precursor and an M sourceprecursor are dissolved in the organic solvent, and the volume mole concentration of the metal precursor in a mixed solution is (1-20)mmol/L; and moreover, oxygen in the solution is discharged under protection of an inertia atmosphere, deposition under subsequent different deposition potentials is performed, and cycle voltammetry electrochemical cleaning is performed. In the catalyst disclosed bythe scheme of the invention, the purposes of further reducing the platinum-loading quantity of the prepared Pt-M metal alloy nanoparticle catalyst, improving the catalytic activity, greatly improvingthe precious comprehensive utilization efficiency, improving the oxygen-reduction performance and reducing comprehensive cost of the precious metal catalyst are achieved.

The invention discloses a preparation method of a graphite felt loaded metal organic framework compound cathode material and an application thereof. The method comprises the following steps: employingferric salt, Pluronic F127, weak acid, 2-aminoterephthalic acid and a carbon felt, adding ferric salt and Pluronic F127 into deionized water; stirring, then adding the weak acid and the 2-aminoterephthalic acid according to the molar ratio, stirring to obtain a metal organic framework compound precursor solution, putting the metal organic framework compound precursor solution and the pretreated carbon felt into a reaction kettle together, sealing, then carrying out a hydrothermal reaction, washing and carrying out vacuum drying to obtain the cathode material. The cathode material has a porousstructure and a large specific surface area, and the yield of H2O2 is remarkably increased when the cathode material is applied to an electro-Fenton system. The oxygen is not required to be filled, aeration is performed or a Fenton reaction reagent is not required to be added in the reaction process, so that the method has a relatively wide pH application range and relatively high acid stability,and almost no iron-based sludge is generated.

The invention provides a carbon supported transition metal atom pair electrocatalyst and a preparation method and application thereof and belongs to the technical field of electrocatalysts. A nitrogen-containing carbon source is used as a carbon source and a nitrogen source, a catalyst precursor with uniformly dispersed transition metal diatom pairs on a carbon substrate is formed through precipitation reaction due to the complexation between transition metal ions and the nitrogen-containing carbon source, and the catalyst precursor is pyrolyzed and annealed in a protective atmosphere of 500-1000 DEG C so that the transition metal diatom pairs are dispersed on a porous carbon material to obtain the electrocatalyst. The double transition metal atoms are introduced, so that the number of active sites of the electrocatalyst can be increased, the activity and the oxygen reduction activity of the electrocatalyst can be effectively improved, and the electrocatalyst has wide application prospect in the fields of metal air batteries and fuel cells. In addition, the preparation method is simple, the price of the required raw materials is low, the equipment is simple, and large-scale industrial production is easy to achieve.

The invention relates to a porphyrin zeolite imidazole framework hybrid electrocatalyst and a preparation method and application thereof, and belongs to the technical field of polymer electrolyte membrane fuel cells. The preparation method comprises the following steps: 1) dissolving porphyrin into an aqueous solution of 2-methylimidazole to obtain a solution A, adding a zinc acetate solution intothe solution A to obtain green precipitates, and carrying out solid-liquid separation, performing drying and grinding to obtain green powder; and 2) carrying out heat treatment on the product obtained in the step 1) at 500-900 DEG C in an inert gas atmosphere for 2h to obtain the non-noble metal electrocatalyst. The porphyrin zeolite imidazole framework hybrid electrocatalyst and the preparationmethod and application thereof have the advantages of the low raw material cost, the simple method, short time consumption, realization of reaction at room temperature, easiness in scale-up synthesis,environmental protection, and avoiding of the use of an organic solvent.

The invention provides a PtNi nano-alloy material. A PtNi nano-alloy comprises PtNi nano-alloy particles of an octahedral structure and PtNi nano-alloy particles of a sphere-like structure. Accordingto the invention, research is carried out from the direction of adjusting the surface morphology and components of the nanoparticles, the stability of the PtNi nano-alloy catalyst is optimized, and the PtNi nano-alloy material with high oxygen reduction catalytic activity and high stability is obtained. The PtNi nano-alloy particles provided by the invention partially maintain the regular octahedron morphology, partially deform and are converted into a spherical shape, and partially are sintered. After the PtNi nano-alloy material is used as the catalyst, the PtNi nano-alloy material shows excellent catalytic performance in an oxygen reduction reaction, the catalytic reaction efficiency is improved, and the Pt loading capacity is reduced. The provided preparation method is simple and convenient, the one-step synthesis is achieved, no extra surfactant is needed for controlling the morphology, cleaning is easy and convenient, and the preparation method can be used for the proton exchangemembrane fuel cells.

The invention relates to a CoO/C catalyst, wherein loading of CoO in the catalyst is 0.01-99.99%, particle size of CoO in the catalyst is 3.5-50nm. A preparation method of the catalyst comprises the following steps: 1)preparation of nano particles: using ammoniacal liquor for hydrolyzing soluble cobalt salt, performing high temperature backflow on its mixing solution to obtain a colloidal solution or a black solid; 2)preparation of CoO/C: uniformly mixing the substance in the step 1) and powdered carbon in a solvent, removing the solvent and drying to obtain the black powder, performing temperature programming on the black powder, performing heat treatment under target temperature to obtain the CoO/C catalyst. The catalyst has the advantages of high oxygen reduction activity under alkaline condition, good stability, low cost of raw materials and preparation, simple preparation technology, and easy batch production, and is very suitable for being as an oxygen reduction catalyst of a metal/air fuel battery, an alkaline polymer dielectric membrane fuel cell under alkaline condition.

The invention provides a preparation method and application of a heteropolyacid/macrocyclic compound/carbon electrocatalyst, and belongs to the field of catalysts for proton exchange membrane fuel cells. A carbon material is dispersed into a solvent, the heteropolyacid and the macrocyclic compound are added, the mixture is subjected to ultrasonic treatment at the temperature of 10-80 DEG C for 0.1-2 hours, suction filtration and washing are conducted until a filtrate is neutral and colorless, and the filtrate is dried to obtain the heteropolyacid/macrocyclic compound/carbon electrocatalyst. The preparation method is simple in operation, easy in control and mild in conditions, and is environment-friendly; the prepared heteropolyacid/macrocyclic compound/carbon electrocatalyst is quite high in oxygen reduction activity, and can be applied to the proton exchange membrane fuel cell.

The invention discloses a Cu2O/N-C oxygen reduction catalyst and preparation and application thereof. The preparation method of the catalyst comprises the steps that a certain amount of zinc salt anda carbon source are dissolved in an organic solvent, a copper source is added, the Cu2O/N-C oxygen reduction catalyst is obtained through pyrolysis, and the amount of generated cuprous oxide is regulated and controlled by adjusting the amount of the added copper source in an experiment. The method is simple and high in repeatability. The catalyst is a composite material of cuprous oxide and nitrogen-doped carbon, the cuprous oxide is an active site for oxygen reduction catalysis, and the nitrogen-doped carbon can improve the conductivity of the material, so that the material has relatively high current density. The prepared optimal material is used as an oxygen reduction catalyst of an aluminum-air battery, the oxygen reduction half-wave potential is 0.8V, and the limiting current densityis 4.6mA/cm<2>.