125 results about "Temperature-programmed reduction" patented technology

The invention discloses a preparation method of a mesoporous confinement nickel-based methane dry reforming catalyst. The methane dry reforming catalyst takes high-temperature-resistant oxide with an orderly mesoporous duct as a carrier, so that nickel is uniformly dispersed in the duct. The preparation method of the methane dry reforming catalyst comprises the steps that mesoporous oxide with high-temperature stability serves as a carrier; a precursor, namely salt of nickel is transported into the mesoporous duct by alcohol under a stirring condition; the internal surface of the mesoporous duct is modified by an alocholic hydroxyl group, so that nickel can be dispersed better; vacuum drying, high-temperature calcination and H2-TPR (Temperature Programmed Reduction) are performed; and the methane dry reforming catalyst with good anti-carbon and anti-sintering property, high activity and high stability is prepared. The method has the advantages that the method is simple in preparation technology, lower in cost, pollution-free, and high in catalysis efficiency.

The invention relates to a boron nitride composite mesoporous oxide nickel-based catalyst and a preparation method thereof. The nano-boron nitride as the carrier having high thermal stability and carbon deposition resistance is combined with active metal anchoring and dispersion based on mesoporous oxides so that the catalytic material having high resistance to sintering and carbon deposition is obtained. The preparation method comprises adding a surfactant and ammonia water into high thermal stability boron nitride and nickel precursors as reactants, carrying out ultrasonic agitation, loading active metal components to the boron nitride nanosheet layer, and carrying out in-situ coating on the surface with an oxide having a mesoporous channel structure. The coated mesoporous structure can realize high dispersion of the active nickel component. Through drying, high temperature calcination and programmed heating reduction, the nickel-based catalyst having high performances and a novel structure is prepared. The boron nitride composite mesoporous oxide nickel-based catalyst has the advantages of simple process, low production cost, no environment pollution and high catalytic efficiency.

The invention relates to a preparation method of a nickel phosphide catalyst carried by a composite carrier. The method is characterized by comprising the following steps: firstly, using activated alumina and relative enzymes and alcohols as raw materials to prepare a composite carrier of TiO2-Al2O3 by adopting an improved sol-gel method; further, selecting suitable nickel salt and phosphate and carrying out ultrasound dipping and drying in microwaves to obtain a catalyst precursor; and finally, increasing a temperature by a program and reducing to obtain the composite support. The composite carrier of TiO2-Al2O3 prepared by the invention not only can effectively overcome the defect that nickel phosphide is apt to react with gamma-Al2O3 to generate AlP4 to lose the activity, but also overcomes the defect that a specific surface area of single TiO2 is relatively small, effectively exerts the strong metal-support interaction (SMSI) of the TiO2, thereby obtaining a hydrodesulfurization catalyst with remarkable activity efficacy.

The present invention relates to the field of Fischer-Tropsch synthesis iron-based catalyst reduction, and discloses a reduction method for a Fischer-Tropsch synthesis iron-based catalyst. The reduction method comprises: in the presence of a reducing gas, carrying out programmed heating reduction on Fischer-Tropsch synthesis iron-based catalyst particles in a fixed fluidized bed reactor, wherein the programmed heating reduction comprises that the heating rate is 10-20 DEG C / h and constant temperature treatment is performed for 2-8 h at a temperature of 120 DEG C when the temperature is from room temperature to 120 DEG C, the heating rate is 5-10 DEG C / h and constant temperature treatment is performed for 3-10 h at a temperature of 220-230 DEG C when the temperature is from 120 DEG C to (220-230) DEG C, and the heating rate is 3-5 DEG C / h and constant temperature treatment is performed for 10-30 h at a temperature of 260-280 DEG C when the temperature is from (220-230) DEG C to (260-280) DEG C. With the reduction method of the present invention, the Fischer-Tropsch synthesis iron-based catalyst can be smoothly subjected to the reduction reaction so as to reduce the influence on the water and the catalyst strength, and with the application of the reduced catalyst in the Fischer-Tropsch synthesis, the advantages of no breaking, high catalyst activity, low CO2 selectivity and low low-carbon hydrocarbon selectivity can be provided.

The invention discloses a method for preparing the carrier catalyst which can be used in aminoethyl alcohol dehydrogenation reaction to prepare the iminodiacetic acid, and relative usage. It comprises following steps: using the copper salt and nickel salt as main raw material, via dipping, drying, high-temperature baking and programmed increasing temperature, to from said catalyst nanometer copper nickel composite catalyst, then using said catalyst in aminoethyl alcohol dehydrogenation reaction to prepare the iminodiacetic acid. Said inventive catalyst has higher reaction activity. And the raw materials are easily to be attained, the producing cost is lower, and it has better application prospect.

The invention relates to a nickel phosphide catalyst containing sulphur and application of the nickel phosphide catalyst. For the nickel phosphide catalyst, the molar ratio of nickel to phosphorus is 0.1-5, the content of phosphorus is 25% or below by atomic percentage. The nickel phosphide catalyst containing sulphur disclosed by the invention has high selectivity in selective hydrogenation reaction of unsatured unsaturated hydrocarbon compounds and nitrobenzene compounds, has selectivity equivalent to that of Ni2P prepared by adopting the traditional temperature programmed reduction method of phosphate, but has activity obviously improved. Compared with the viewpoint generally known in the prior art that sulphur has side effects for metal hydrogenation catalysts or metalloid hydrogenation catalysts, i.e., sulphur is a toxicant and can be used for greatly reducing the activity of the catalyst, the nickel phosphide catalyst containing sulphur provided by the invention has the advantage that by introducing an appropriate amount of sulphur into the Ni2P catalyst, the hydrogenation activity of the Ni2P catalyst can be significantly improved under the condition that the selectivity of the Ni2P catalyst is not affected.

The invention discloses a dehydrogenation catalyst reduction method. Dehydrogenation catalyst is platinum family loading catalyst and is in programmed temperature rising reduction before being used, the programmed temperature rising reduction is performed within a temperature range between 350 DEG C and 600 DEG C, and temperature rising speed ranges from 0.5 DEG C / min to 10 DEG C / min. In an activating process of the dehydrogenation catalyst, after platinum-base catalyst is prepared by a conventional method, conventional constant-temperature reduction operation is omitted, a programmed temperature-rising reduction method is utilized to realizing activation reduction for the catalyst, so that metal particles of the catalyst after being in reduction are dispersed more uniformly, sizes of theparticles are proper, and surface area of exposed elementary substance Pt is enlarged. Accumulation of activated metal of the catalyst due to deep reduction of dehydrogenation activated metal is avoided, deep reduction of addition agent components which do not need reduction can also be avoided, accordingly, service performances of the catalyst are improved, and particularly, selectivity of objective products and stability of long-term reaction are improved.

The invention discloses a preparation method of supported Ni2P catalyst. The preparation method of the supported Ni2P catalyst comprises the following steps: preparing a silicon dioxide, MCM-41, SBA-15, aluminium oxide, titanium oxide, HY molecular sieve or HZSM-5 molecular sieve supported nickel oxide precursor by adopting an impregnation way; reducing the supported nickel oxide precursor into a supported Ni precursor in a fixed bed reactor, then introducing hydrogen, introducing a triphenylphosphine or tri-n-octylphosphine solution into the fixed bed reactor at a certain temperature, and phosphating for a period of time at constant temperature, thus obtaining the supported Ni2P catalyst in situ. Compared with a general method for preparing the supported Ni2P catalyst by adopting a supported nickel phosphate temperature programmed reduction method, the preparation method of the supported Ni2P catalyst is simple and practicable, generation of aluminium phosphate owning to reaction between phosphorus species and aluminium oxide in a carrier can be avoided, and the phosphorus species can be effectively utilized.

A supported nickel phosphide catalyst has quite high hydrogenation desulfurization activity and relatively good activity stability. A traditional nickel phosphide catalyst is prepared by a way of temperature programming reduction of nickel phosphate, and the dispersion degree of active components is relatively low. Firstly, a silica supported nickel precursor is reduced or roasted under a hydrogen atmosphere, then a phosphating solution is introduced and phosphorization is carried out at lower temperature, and thus the Ni2P / SiO2 catalyst having quite high dispersion degree of the active components and having quite high hydrogenation desulfurization and denitrification activity is obtained. The catalyst can also be used for hydrogenation treatment on diesel oil and for production of clean diesel oil, and also can be used in sulfur-resisting hydrogenation reactions of other occasions.

The invention discloses preparation of a confinement structure ruthenium-nickel core-shell bimetallic nano-catalyst and application thereof in catalyzing dimethyl terephthalate selective hydrogenation. The structure of the catalyst is that Ru@Ni core-shell metal nanoparticles are uniformly embedded in a weakly crystallized aluminium-doped nickel metallic oxide shell, and peripheral aluminium-dopednickel metallic oxide has a confinement effect on the Ru@Ni core-shell metal nanoparticles. The preparation method comprises the steps that a NiAlRu ternary hydrotalcite precursor is synthesized through a double drop method, then temperature-programmed reduction is applied in a hydrogen atmosphere, and the confinement structure ruthenium-nickel core-shell bimetallic nano-catalyst is obtained. Ina dimethyl terephthalate selective hydrogenation reaction, by means of the catalyst, not only is the conversion rate of dimethyl terephthalate is improved, but also the selectivity of dimethyl 1,4-cyclohexanedicarboxylate is greatly improved, the outstanding reaction stability is achieved, and thus the reaction performance of hydrogenation is improved.

Provided is a highly selective fischer-tropsch process for producing liquid hydrocarbon, which comprises that a mixing air of hydrogen and carbonic oxide is contacted with an catalyst under fischer-tropsch synthesis condition. The process is characterized in that the catalyst contains efficient quantity of cobalt metal component and oxide of alumina, wherein the RT value of the cobalt metal component is 400 DEG C to 1000 DEG C, the RT value is the summit temperature corresponding to the first reduction peak of the first reduction peak in a reduction spectrogram of cobalt which exists in an oxidation state form when representing the catalyst with the employment of temperature programmed reduction. Compared with the existing technology, the C5+ selectivity of the process provided by the invention is remarkably increased.