30results about How to "Catalytic activity does not decay" patented technology

The invention relates to a catalyst for preparing chloroacetic acid from acetic acid and its preparation and application. The preparation method of the catalyst is as follows: (1) Mix phenol and formaldehyde aqueous solution, add metal powder and metal oxide, disperse and then heat the reaction (2) continue to add paraformaldehyde solid and / or hexamethylenetetramine in the reaction gained solution, stir and mix evenly, obtain the viscous liquid mixture, discharge while hot, granulate, obtain bar-shaped particle: ( 3) Dry the obtained strip-shaped particles, heat up and solidify, and then continue to heat up under the protection of an inert gas to obtain carbonized / graphitized particles; (4) finally elute the obtained carbonized / graphitized particles with aqueous nitric acid solution to obtain the target product. Compared with the prior art, the present invention effectively solves the problems of separation of the catalyst and the reaction solution, greatly improves the selectivity of the main product chloroacetic acid, and greatly reduces the production cost and labor intensity.

The invention relates to a MoS2 nanosphere difuncitonal oxygen catalyst of a hierarchy structure a preparation method thereof and application thereof in electrocatalyzing oxygen in an alkaline medium. The MoS2 nanosphere difuncitonal oxygen catalyst is MoS2 nanospheres which are synthesized by taking Na2MoO4 and KSCN as raw materials and adopting a hydrothermal method and have the hierarchy structure, and the MoS2 nanospheres are formed by a plurality of MoS2 nanosheets, so that the MoS2 nanospheres have a large specific surface area, and edge sits of the MoS2 nanosheets are fully exposed. Due to multiporous flower-shaped nanospheres formed by ultra-thin MoS2 nanosheet units, the effective electrochemical catalysis area and the catalytic sites are increased, and the electron conduction rate is quickened, so that overpotential of an oxygen evolution reaction and an oxygen reduction reaction can be effectively reduced; a rotating disk electrode and a rotating ring disk electrode show that the oxygen reduction process is based on a four-electron catalytic mechanism and is a relatively ideal oxygen reduction reaction process.

The invention discloses a high-performance alkaline fuel cell cathode carbon catalyst and a preparation method of the high-performance alkaline fuel cell cathode carbon catalyst. The catalyst disclosed by the invention is a composite carbon material in a core-shell nanostructure, which is prepared by adulterating two elements of Fe and N, using conductive carbon black with a high-ratio surface as an inner core and coating a phthalocyanine iron shell around the inner core. The preparation method comprises the following steps of: weighing and mixing phthalocyanine iron solid powder and the conductive carbon black with the high-ratio surface according to a certain mass ratio, and then preparing to obtain a C@FePc carbon non-noble metal catalyst in the core-shell nanostructure by adopting a simple mechanical ball milling method. The catalyst disclosed by the invention has high-performance oxygen reduction reaction (ORR) catalytic activity, excellent CH3OH / CO tolerance and good stability, the cost of raw materials used in the preparation process is low, the operation is simple and convenient, and the catalyst is easy for large-scale commercialized production.

The invention discloses a double-functional catalyst of carbon-based non-noble-metal oxygen electrode and a preparation method thereof. The catalyst is a composite material composed of metal, metal oxide grains, N-doped graphene, carbon spheres and nanotubes. The preparation method of the catalyst comprises the following steps of: 1) weighing graphite oxide or graphene oxide, the carbon spheres, a metal compound and a nitrogen-containing heterocyclic compound according to ratios; carrying out ultrasonic treatment on the raw materials in a solvent; uniformly agitating and sufficiently drying to obtain a precursor; and 2) carrying out high-temperature pyrolysis in a precursor inert atmosphere to obtain a composite material catalyst. The catalyst provided by the invention not only has the advantages of high oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) catalytic performances, good stability and excellent CH3OH / CO tolerance, but also the cost of the raw materials is low, and the preparation method is simple and is easy to operate.

The invention provides an iron-based nano-array electrocatalytic electrode, a preparation method thereof and an alkaline fuel cell. The iron-based nano-array electrocatalytic electrode comprises an iron-based substrate and a nano-array structure on the surface of the iron-based substrate, and the nano-array structure is composed of a compound of iron oxide and ferroferric oxide. The iron-based nano-array electrocatalytic electrode is prepared through anode oxidation, ultrasonic-assisted anode oxidation and annealing treatment. The iron-based nano-array electrocatalytic electrode can promote oxygen reduction reaction in an alkaline medium, cathode oxygen reduction peak current density and semiwave potential can be close to those of a commercial Pt / C catalyst, initial potential forward movement is 50mV, electrocatalytic effect is good, catalytic activity of the electrode after being used for a long time is basically free of attenuation, current density is increased by higher than 30%, and stability and catalytic activity are both improved. The iron-based nano-array electrocatalytic electrode is simple to prepare, low in cost and good in application prospect.

The invention relates to a method for preparing graphene / nickel-iron hydrotalcite nanosheet bifunctional oxygen catalyst in one step and its electrocatalytic application to oxygen evolution reaction and oxygen reduction reaction in alkaline medium. The invention uses graphene oxide as the substrate, grows ultra-thin nickel-iron hydrotalcite nanosheets in situ in a mixed solution of formamide and water, and then prepares a graphene / nickel-iron hydrotalcite nanosheet composite oxygen catalyst by thermal reduction , this method avoids the steps of water-like stripping and chemical reduction of graphene oxide, increases the active sites of the catalyst, inhibits the aggregation of graphene and nickel-iron hydrotalcite nanosheets in the composite, and improves the composite Conductivity, the obtained catalyst reduces the overpotential of oxygen evolution and oxygen reduction reactions in alkaline media, reduces its electron transfer resistance, shows good oxygen catalytic performance and stability, and provides a basis for the development of potential bifunctional oxygen catalysts important method.

The invention discloses a mine-used rapid plugging polyurethane foam material and a preparation method thereof, belonging to mine-used polymer materials. The technical solution is composed of A-component composite material and B-component composite material; the above-mentioned component A composite material and B-component composite material are respectively packed in two metal steel cylinders A and B, and are supplied to the two metal cylinders A and B respectively. Nitrogen is filled in the middle to pressurize, and the pressure inside the metal cylinder A is controlled to be 2.0-2.1Mp.a, and the pressure inside the metal cylinder B is 2.1-2.2Mp.a, and then the materials A and B are passed through the spray gun at a mass ratio of 1:1 , ‑NCO:‑OH=1.09~1.25:1 The molar ratio of reactive groups is mixed and sprayed. After the A and B materials are mixed through the nozzle of the spray gun, the rapid plugging polyurethane foam material for mining can be formed. The invention makes the polyurethane foam formed by spraying have good toughness and bonding strength, and enhances the plugging and sealing effect.

The invention discloses graphene / stripped hydrotalcite composite material non-noble metal bifunctional oxygen catalyst modified covalently by an ionic liquid, a preparation method thereof, and an electrical catalytic application of the catalyst for an oxygen evolving reaction (OER) and an oxygen reduction reaction (ORR) in an alkaline medium. By means of special solubility and high electric-conductivity the ionic liquid, through covalent modification, the ionic liquid is introduced onto surface of a graphene / stripped hydrotalcite composite material to prepare the graphene / stripped hydrotalcite composite material modified covalently by the ionic liquid. The oxygen catalyst, under an alkaline condition, has high OER and ORR bifunctional catalytic activity, excellent dispersibility and excellent methanol tolerance, is low in raw material cost and simple in preparation method, is easy to use and is convenient to produce in large scale.

The invention discloses a metal organic skeleton compound-based cobalt-carbon porous nanocomposite oxygen reduction electrocatalyst and its preparation method and application. The cobalt-carbon porous nanocomposite oxygen reduction electrocatalyst is prepared from a metal organic skeleton compound [Co(O-BDC)(bbp)] as a precursor through high-temperature calcination. The carbon material has a porous structure. A cobalt element is uniformly supported on the carbon material. The oxygen reduction electrocatalyst has high electrical conductivity and a large specific surface area and effectively reduces the overpotential of oxygen reduction. Through a rotating disk electrode and a rotating ring electrode, it is proved that the oxygen reduction process is an ideal 4 electron oxygen reduction catalytic process. The electrocatalyst fully performs synergism of cobalt and a carbon material in electrocatalysis and has great theoretical and practical significance for the development of novel electrochemical catalysts and energy conversion and storage devices.

The invention discloses a non-noble metal catalyst and a preparation method thereof. The preparation method comprises the steps as follows: (1) a metal compound and an organic molecule linking agent are dissolved respectively in proportion, two solutions obtained after dissolution are uniformly mixed, and thus, metal ions and organic molecules are subjected to a chelation reaction to produce precipitates; the precipitates are subjected to centrifugal or suction filtration treatment, an intermediate product is obtained and dried, and a precursor is obtained; (2) the precursor is subjected to pyrolysis carbonization treatment in an inert atmosphere, and the non-noble metal catalyst is obtained. The prepared non-noble metal catalyst takes an organic metal framework structure as a core, has multi-walled carbon nanotubes on the surface and has the larger specific surface area; the non-noble metal catalyst has good oxygen reduction catalytic performance, oxygen evolution catalytic performance, stability and CH3OH tolerance and can maintain long-term and stable catalytic activity when applied to fuel cells.

The invention relates to a non-metallic bi-functional oxygen catalyst for graphene / nickel iron type hydrotalcite as well as a preparation method and electric catalytic application thereof to oxygen evolution reaction and oxygen reduction reaction in an alkaline medium. The catalyst takes a micelle as a template, and under the hydrothermal and reducing conditions, the nickel iron type hydrotalcite is assembled onto graphene in sequence to form a spherical porous graphene oxide / nickel iron type hydrotalcite compound. The method comprises the following steps: dispersing graphene oxide and metal salt in the micelle, introducing an alkali source, synthesizing the graphene oxide / nickel iron type hydrotalcite compound under the hydrothermal conditions, and performing hydrazine hydrate reduction on an obtained product to obtain the catalyst. The catalyst prepared by the method has high oxygen evolution and oxygen reduction catalytic activity, good stability and excellent methanol tolerance under the alkaline conditions and is low in cost of raw materials used, simple in preparation method, easy to operate and convenient for large-scale production.