535results about How to "Reduce overpotential" patented technology

Catalysts comprised of at least one catalytically active element and at least one helper catalyst are disclosed. The catalysts may be used to increase the rate, the selectivity or lower the overpotential of chemical reactions. These catalysts may be useful for a variety of chemical reactions including in particular the electrochemical conversion of carbon dioxide to formic acid.

The present invention involves increasing the quantum efficiency in titania photocatalysts for photocatalytic (oxidation of acetaldehyde) and photosynthetic (photosplitting of water) reactions by integrating the titania photocatalyst with a polar mineral having surface electrical fields due to pyroelectric and piezoelectric effects, and by adjusting the nanostructure of the photocatalyst materials. The photocatalytic reactivity of titania powder is increased due to the effect of electric field present on the surface of polar mineral material on the photocatalytic effect of commercial titania with respect to photolysis of water. Additionally, the photocatalytic performance of pure phase rutile and anatase nanostructures with well defined morphologies was found to improved with respect to certain photocatalytic reactions in comparison with non-structured titania.

The present invention provides molybdenum and tungsten nanostructures, for example, nanosheets and nanoparticles, and methods of making and using same, including using such nanostructures as catlysts for hydrogen evolution reactions.

The invention discloses a nano loaded titanium-based electric catalytic film comprising a conductive microporous separating titanium film matrix and a catalytic coating. Furthermore, the invention also discloses a preparation method of the nano loaded titanium-based electric catalytic film, which comprises the following steps of: (1) preprocessing the titanium film matrix by sand blasting, alkali washing, and acid etching: soaking the matrix after sand blasting in an NaOH solution for 0.5 to 2h, then processing for 1 to 2h in an oxalic acid solution with the mass percent concentration of 10 percent after washing to a neutral state, washing with water and drying at 100 to 120 DEG C; and (2) preparing and loading a catalytic coating: preparing the catalytic coating by adopting a sol-gel method, a thermal decomposition method, an electrodeposition method or a chemical vapor deposition method and loading at the surface of the titanium film matrix and in a hole. Furthermore, the invention also discloses a film reactor comprising the nano loaded titanium-based electric catalytic film. According to the nano loaded titanium-based electric catalytic film, the defects on material strength, range limitation of working voltage, catalytic oxidation efficacy and the like in the prior art are solved.

The invention discloses a nickel-and-molybdenum based bimetallic carbide loaded on nickel foam and a preparation method and application thereof. Nickel nitrate and ammonium molybdate are adopted as a nickel source and a molybdenum source correspondingly, glucose is adopted as a carbon source, and the bimetallic carbide Mo6Ni6C is grown on the surface of the nickel foam in situ through a hydrothermal and high-temperature carburizing method. The method is easy and convenient to implement, the raw materials are easy to obtain, the preparation cost is low, the reaction period is short, and repeatability is high. The material has the excellent hydrogen evolution performance in the field of electrocatalytic decomposition of water. When the overpotential of hydrogen evolution is -51 mV in an acid electrolyte solution, the electric current density can reach 8-12 mA/cm<2> and is not decreased obviously under the stable work for more than 200 hours; and at the same time, when the overpotential of hydrogen evolution is -34 mV in an alkali electrolyte solution, the electric current density can also reach 8-12 mA/cm<2> and is not decreased obviously under the stable work for more than 300 hours. The nickel-and-molybdenum based bimetallic carbide loaded on the nickel foam not only can be directly used as a working electrode of electrocatalytic hydrogen evolution, but also can be used in the fields of the chlor-alkali industry, the water electrolysis process, solar energy water electrolysis and hydrogen manufacturing and the like.

The invention relates to electrochemical power sources and the field of electrochemical catalysis, and particularly relates to a transition metal nitride/carbon electrocatalyst. The transition metal nitride/carbon electrocatalyst comprises a substrate and a shell, the substrate is coated by the shell, and the shell comprises copper nitride and further comprises a carbon material or a nitrogen doped carbon material. The invention further provides a preparation method of the electrocatalyst, and the electrocatalyst is prepared by forming MOF of copper in advance, then further aminating and calcining through one step, and preparing the electrocatalyst. The processes of oxygen precipitation and hydrogen precipitation show the low overpotential in the alkaline environment, and the electrocatalyst can be used as a catalyst material of alkaline efficient electrolysed water.

This invention discloses a high-performance metal/graphite composite dyed electrode used in dye-sensitized solar cell and its preparation method, which takes graphite as the basic material that mixes with the small-sized inorganic solid particles, and the mixture is pressed into the porous metal grid under a certain pressure, forming the porous electrode material with high-ratio surface area. The surface resistance of this composite electrode is very small, which can receive the photoelectric transmission properties comparing with the platinum electrode when the effective contact area between graphite and liquid electrolyte in the dye-sensitized nanocrystal solar cell is larger.

The invention provides a CeO2-NiCo2O4/NFcomposite electrocatalytic material and a preparation method and application thereof. The method includes the steps that a nickel-cobalt hydroxide precursor (NiCo2-OH/NF) is grown in situ on the surface of foamed nickel through a hydrothermal method, a one-dimensional NiCo2O4 nanowire is constructed on the surface of the foamed nickel through roasting treatment, finally, CeO2 are uniformly deposited on the surface of the NiCo2O4 nanowire through an electro-deposition method to obtain the CeO2-NiCo2O4/NF composite electrocatalytic material, wherein NiCo2O4 is of a spinel structure, NiCo2O4 is oriented to form the nanowire growing vertically on the surface of a foamed nickel sheet substrate, and the CeO2 are uniformly deposited on the surface of NiCo2O4. The composite electrocatalytic material has excellent electrocatalytic oxygen evolution activity and stability, when the current density is 10 mA.cm<-2>, in the alkaline electrolyte environment, the oxygen evolution overpotential of CeO2-NiCo2O4/NF is 261-217 mV, and the oxygen evolution overpotential is 401-334 mV in the acidic electrolyte environment; and the catalytic material is used for anelectrocatalytic oxygen evolution reaction of water.

The invention discloses a preparation method of a Ni3Fe-loaded nitrogen-doped carbon nanometer composite material, and a product and applications thereof. The preparation method comprises following steps: 1, a Ni<2+>/Fe<3+>/PVP mixed sol is prepared; 2, the Ni<2+>/Fe<3+>/PVP mixed sol is subjected to electrostatic spinning so as to obtain solid carbon fiber film; 3, the solid carbon fiber film issubjected to pre-oxidation at air atmosphere at 200 to 300 DEG C, programmed heating is adopted for heat processing at 400 to 1000 DEG C at an inert atmosphere so as to obtain the Ni3Fe-loaded nitrogen-doped carbon nanometer composite material. The preparation method is low in cost, is easy, and is universal; the obtained Ni3Fe-loaded nitrogen-doped carbon nanometer composite material is of a one-dimensional composite structure (carbon nanometer fiber and carbon nanotube); Ni3Fe alloy particles can be embedded into the carbon nanometer fiber and carbon nanotube uniformly; the Ni3Fe-loaded nitrogen-doped carbon nanometer composite material can be taken as a water electrolysis hydrogen evolution electrocatalytic material, and possesses relatively high activity and excellent stability.

The invention discloses a metal-CO2 battery. The metal-CO2 battery comprises a positive electrode, a negative electrode, an organic electrolyte and a separator, wherein the positive electrode is an IrO2/MnO2 composite electrode with a hierarchical structure, comprises sheet-shaped MnO2 and also comprises nanometer IrO2 particles, the sheet-shaped MnO2 is directly grown on a substrate, strip-shaped MnO2 also covers a surface of the sheet-shaped MnO2, the nanometer IrO2 particles are uniformly loaded on the surfaces of the sheet-shaped MnO2 and the strip-shaped MnO2, and the negative electrode is selected from an alkali metal electrode subjected to surface protection processing. The invention discloses the metal-CO2 battery, the IrO2/MnO2 composite electrode with the hierarchical structure is used as the positive electrode, the alkali metal electrode subjected to surface projection processing is used as the negative electrode, electric energy is generated by greenhouse gas CO2, and the metal-CO2 battery obtained by assembly shows low polarization, high capacity and long cycle lifetime.

The invention provides a tetracobalt trisulfide nanometer hollow tube@foam nickel composite array material and a preparation method and application thereof. Compared with the prior art, a hydrothermal method for preparing the tetracobalt trisulfide nanometer hollow tube@foam nickel composite array material has the advantages of mature and stable synthesizing process, easiness in operation, low influence by the environment, easiness in controlling and high yield. The synthesized tetracobalt trisulfide nanometer hollow tube@foam nickel composite array material is of a one-dimensional hollow tubular structure and has a large surface-specific area, and a Co4S3 nanotube directly grows on a foam nickel substrate with high conductivity, so that a product has high electrocatalytic activity in a hydrogen evolution reaction. Compared with other electro-catalysts loaded with noble metal elements, the tetracobalt trisulfide nanometer hollow pipe@foam nickel composite array material has the advantages that a transition metal is effectively combined with foam nickel to serve as an electro-catalyst of the hydrogen evolution reaction, and raw materials are rich in sources and cheap, so that the cost of the electro-catalyst of the hydrogen evolution reaction is lowered greatly.

The invention discloses a Co-Se compound nanotube@ foam Ni composite array material as well as a preparation method and an application thereof. The method comprises the following steps: firstly, Co salt and urea are dissolved in deionized water, foam Ni is added, and a Co precursor@ foam Ni composite is prepared through a hydrothermal reaction; then a Se source is dissolved in hydrazine hydrate, the obtained solution is mixed with deionized water, the Co precursor@ foam Ni composite is added, and the Co9Se8 nanotube@ foam Ni composite array material is obtained through a hydrothermal reaction.The raw materials and process equipment are simple, the preparation cost is low, the product yield is high, and the prepared composite is a 1D hollow-structured Co9Se8 nanotube array directly growingon a foam Ni substrate with good electrical conductivity, can directly serve as an electrode material to be applied to catalysis of water electrolysis for a hydrogen evolution reaction, shows excellent catalytic performance and has huge potential application value in the field of water electrolysis for hydrogen production.

The invention relates to a MoS2/Ni3S2 electrode material as well as a preparation method and application thereof, which belongs to the technical field of environmental protection and energy of hydrogen production by virtue of electric decomposition of water. The application of different sulfur sources is verified to have great influence for the morphology and performance of a catalyst; and by virtue of comparison, the MoS2/Ni3S2 electrode synthesized by using thioacetamide as a sulfur source has optimum morphology, performance and reaction active site, the over-potential for the reaction can be greatly reduced, and the energy loss in the electrochemical hydrogen production process can be reduced. Meanwhile, the synthetic method is simple, and the foam nickel self-supported MoS2/Ni3S2 electrode can be synthesized by adopting a one-step hydrothermal method, so that the industrialized production and actual application value is high.

The invention discloses a preparation method and application of an oxygen reduction cathode catalyst of an aluminum-air battery. According to the preparation process of the oxygen reduction catalyst, chitosan serves as a carbon source and a transition metal chelating agent, urea serves as a nitrogen source, and pyrolysis is carried out under nitrogen protection. The sample obtained through the method serves as the oxygen reduction cathode catalyst of the aluminum-air battery, the catalyst is low in cost, rich in resource and simple in operation, has good catalytic action on oxygen reduction, and can be a new oxygen reduction catalyst hopefully.

In some embodiments a ternary electrocatalyst is provided. The electrocatalyst can be used in an anode for oxidizing alcohol in a fuel cell. In some embodiments, the ternary electrocatalyst may include a noble metal particle having a surface decorated with clusters of SnO₂ and Rh. The noble metal particles may include platinum, palladium, ruthenium, iridium, gold, and combinations thereof. In some embodiments, the ternary electrocatalyst includes SnO₂ particles having a surface decorated with clusters of a noble metal and Rh. Some ternary electrocatalysts include noble metal particles with clusters of SnO₂ and Rh at their surfaces. In some embodiments the electrocatalyst particle cores are nanoparticles. Some embodiments of the invention provide a fuel cell including an anode incorporating the ternary electrocatalyst. In some aspects a method of using ternary electrocatalysts of Pt, Rh, and SnO₂ to oxidize an alcohol in a fuel cell is described.

The invention relates to a negative electrode material of a flexible sodium metal battery and a preparation method thereof and belongs to the technical field of sodium metal batteries. The negative electrode material is characterized in that graphene aerogel is adopted as a skeleton, and sodium metal is distributed in a skeleton structure; the hole diameter range of the skeleton is 20-200mu m, andthe mass percentage of the sodium metal in the negative electrode material is 90-98%. The preparation method of the negative electrode material comprises the following steps of: adding a conducting material into water, then adding a reducing agent, and reacting for 6-24 hours at the temperature of 50-200 DEG C to obtain an intermediate product; washing with water, freezing drying under 5-10 MPa to form the graphene aerogel; then adopting the graphene aerogel as a skeleton, and compounding with liquid metal sodium to obtain the negative electrode material. The negative electrode material has good flexibility, uniform porosity and large specific surface area; as a negative electrode of the sodium metal battery, uniform nucleation of sodium ions is ensured, the volume expansion in the circulating process is relieved, and due to higher conductivity, the overpotential is effectively reduced.

The present invention relates to materials for cathode in solid oxide fuel cells, more particularly, an oxide having high oxygen vacancies and high conductivity as cathode, which is able to accelerate absorption of oxygen molecule and diffusion of oxygen ion for reducing internal resistance of cells, in other words, reducing overpotential of cathode, and improvement of electric generation efficiency of fuel cells. General form of the cathode materials is Ln_1-xA_xCu_1-yB_yO_2.5±δ, wherein Ln is lanthanide ion, A is alkaline-earth metal, B is metal. Cathode dope different alkaline-earth metal on A side to converse partly copper (Cu) to trivalence copper ion for forming perovskite having oxygen vacancies with regularity sequence, by utilizing catalytic of cathode electrode accelerating cathode reaction and compound electron being conducted though external circuit with conversing oxygen to form oxygen ion for obtaining anode and hydrogen reaction by diffusing oxygen ion to electrolyte.

The invention provides a noble metal supported nano frame catalyst and a preparation method and application thereof. The catalyst comprises noble metals and transition metal hydroxides, and is of a hollow nano frame structure. According to the noble metal supported nano frame catalyst, the catalyst is of a hollow nano frame structure, so that the activation specific surface area is large, the wallthickness is small, and the substance transmission distance is short; the catalyst supports a nickel cobalt hydroxide with the noble metals, so that the electronic structure between the nickel cobalthydroxide and the noble metals is optimized, the stability of the catalyst is high; the overpotential of catalyzing a hydrogen evolution reaction can be effectively reduced, wherein the overpotentialis only 60 mV when the current density is 10 mA cm-2; and the catalyst is simple in preparation method, short in production cycle, and wide in application prospect.

The invention discloses an eutrophicated river water quality purifying method. The method comprises the following steps of: intercepting eutrophicated river into upstream, midstream and downstream parts; then conveying water of the upper part into an electrolyzing machine to be electrolyzed; then, discharging the electrolyzed water into the midstream part to be subjected to aeration treatment at the midstream part; and finally, flowing the water subjected to the aeration treatment to the downstream part. The eutrophicated river water quality purifying method adopts a method for firstly electrolyzing and secondly aerating, and can effectively inhibit the growth of algae in the water and an anaerobic reaction of a water body; an organic matter is decomposed, and total nitrogen, total phosphorus and chromaticity in the water are reduced and the odor is removed, so as to improve the river water quality and recover a water ecological system in a shorter time. The invention further discloses a river water quality purifying device, comprising a rubber dam, a water pump, the electrolyzing machine and an aeration device. The river water quality purifying device can be directly mounted in a river to directly purify river water; and the river does not need to be specially leaded to a pre-set structure to be treated, and the river water quality purifying device nearly does not change an environment, so that the influences to a natural environment are smaller.