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 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 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 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 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.