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CN-118059911-B - Ammoniation heterogeneous interface regulation and control Co-Mo2Preparation method and application of C@NC diatomic catalyst

CN118059911BCN 118059911 BCN118059911 BCN 118059911BCN-118059911-B

Abstract

The invention discloses a preparation method and application of an ammoniation heterogeneous interface regulation Co-Mo 2 C@NC diatomic catalyst. The cobalt (Co) and molybdenum (Mo) salts are used as precursors, a nano rod-shaped crystal of cobalt molybdate (CoMoO 4 ) is prepared by a hydrothermal method, a high-nitrogen and carbon compound is used for preparing a polymeric carbon Nitride (NC) heterostructure (N-Pot) by adopting a hydrogen and nitrogen atmosphere temperature programming in-situ topological phase transition, and the nano cobalt molybdate (CoMoO 4 ) is anchored on the N-doped carbon heterostructure of the polymeric carbon nitride by annealing, so that the Co-Mo 2 C@NC diatomic catalyst is prepared. The catalyst prepared by the method is used for continuous ammonification and cycloamination of materials containing glycol hydroxyl groups, namely Ethylene Glycol (EG), diethylene glycol (DEG), dihydroxyammonification and cycloammonification to prepare high-attachment organic amine products such as ethylenediamine, piperazine, diglycolamine, morpholine and the like. Realizing continuous operation of the production process, and realizing equipment serial regulation for industrial production of different amine derivatives.

Inventors

  • XIE AIDI
  • XIE SHUXUAN
  • WU QINGMEI

Assignees

  • 合肥飞木生物科技有限公司

Dates

Publication Date
20260508
Application Date
20240220

Claims (9)

  1. 1. The preparation method of the ammoniated heterogeneous interface regulation Co-Mo 2 C@NC diatomic catalyst is characterized by comprising the following steps: (1) Preparation of catalyst precursor cobalt molybdate CoMoO 4 Respectively weighing soluble metal cobalt salt and molybdenum salt, preparing into an aqueous solution, fully mixing the aqueous solution with polyethylene glycol/aqueous solution, fully and uniformly mixing a reaction raw material and the structure directing agent, adding the mixture into a hydrothermal reaction kettle, stirring, controlling the temperature and the pressure, reacting for 10-60min, cooling to room temperature and releasing pressure after the reaction is finished, centrifugally separating an obtained superfine product, washing the superfine product with distilled water for 3-5 times, and drying the superfine product in a 50-100 ℃ normal pressure or negative pressure environment for 10-24h to prepare a cobalt molybdate CoMoO 4 nanorod material; (2) Preparation of polymeric carbon nitride NC heterogeneous carrier Weighing precursors with high nitrogen content (N) and carbon content (C) and/or triazine compounds, heating to 400-600 ℃ in a hydrogen-nitrogen mixed gas atmosphere by temperature programming, preserving heat for 6-24 hours at a final temperature, and naturally cooling to room temperature after in-situ topological phase change is completed to obtain a polymeric carbon nitride NC heterogeneous carrier; The precursor of Gao Handan (N) and carbon (C) and/or triazine compound is selected from one or more than two of dicyandiamide, melamine, cyanuric acid, trichloroisocyanuric acid, thiourea and urea; (3) Preparation of Co-Mo 2 C@NC diatomic catalyst Dispersing cobalt molybdate CoMoO 4 nano substances obtained in the step (1) into absolute ethyl alcohol, adding dicyandiamide DCDA as a carbon source and a nitrogen source of metal nitride and metal carbide according to a molar ratio of 1:10, adding different molybdenum and cobalt loadings into the polymeric carbon nitride NC heterogeneous carrier prepared in the step (2), uniformly mixing, heating to 500-1000 ℃ in a hydrogen-nitrogen mixed gas atmosphere by a program temperature, preserving heat for 6-24 hours at a final temperature, naturally cooling to room temperature, and further carrying out an annealing process after loading, wherein in-situ carbonization and nitridation of the cobalt molybdate nano rod are due to nitrogen carbon substances CN - released by pyrolysis of dicyandiamide, so that a certain amount of metal nitrides MoN and CoN and molybdenum carbide Mo 2 C are formed, and are embedded into the polymeric carbon nitride NC heterogeneous carrier, thus obtaining the catalyst Co-Mo 2 C@NC for ammoniation.
  2. 2. The preparation method according to claim 1, wherein the soluble cobalt salt in the step (1) is selected from one or more of cobalt chloride, cobalt sulfate, cobalt nitrate and cobalt acetate; the soluble metal molybdenum salt is selected from one or more than two of ammonium molybdate, potassium molybdate, sodium molybdate and ammonium dodecamolybdate phosphate, the polyethylene glycol is selected from one or more than two of polyethylene glycol 200, polyethylene glycol 400, polyethylene glycol 600, polyethylene glycol 800, polyethylene glycol 2000, polyethylene glycol 6000 and polyethylene glycol 12000, and the concentration of the polyethylene glycol/water solution is 0.01-2 mol/L.
  3. 3. The preparation method of the hydrogen-nitrogen mixture according to claim 1, wherein in the step (2), the hydrogen volume is 10% and the nitrogen volume is 90%, the temperature is raised at a temperature raising rate of 2-10 ℃ per minute, the temperature is kept at a final temperature of the temperature programming, the temperature is kept for 6-24 hours, and the mixture is naturally cooled to room temperature.
  4. 4. The method according to claim 1, wherein in the step (3), the molar ratio of cobalt molybdate CoMoO 4 to dicyandiamide is 1:10, and the Co-Mo 2 C bimetallic compound can be formed during annealing pyrolysis, and the bimetallic compound is embedded in the polymeric carbon nitride NC heterogeneous carrier.
  5. 5. The method according to any one of claims 1-4 for preparing an ammoniated heterogeneous interface regulation Co-Mo 2 C@NC diatomic catalyst.
  6. 6. The application of the Co-Mo 2 C@NC diatomic catalyst as claimed in claim 5 is characterized by being applied to continuous ammonification of alcohol hydroxyl groups and serial ring ammonification.
  7. 7. The process of claim 6, wherein the alcohol hydroxyl groups of ethylene glycol or diethylene glycol are continuously aminated, and the serial ring amination is used for selectively synthesizing ethanolamine, ethylenediamine, piperazine, hydroxyethyl piperazine, or diglycolamine, morpholine and dimorpholine ethyl ether.
  8. 8. The use according to claim 7, wherein the specific steps of the alcohol hydroxyl continuous ammonification synthesis, serial cyclic ammonification reaction selective synthesis of ethanolamine, ethylenediamine, piperazine and hydroxyethyl piperazine applied to glycol are as follows: Grinding, tabletting, crushing and screening the Co-Mo 2 C@NC diatomic catalyst to obtain a 40-60 mesh small granular catalyst; The reactor adopts a fixed bed tubular reactor, two single pipes are connected in series, the inner diameter of each single pipe is 20mm, the length of each pipe is 300mm, independent sampling is carried out, and control parameters are set; Filling the catalyst in a constant temperature zone of a fixed bed reactor respectively, reducing for 6-12 hours at 100-300 ℃ by using hydrogen with the flow rate of 100-300 ml/min, cooling, and feeding ethylene glycol EG for reaction by a high-pressure constant-flow pump; feeding, wherein the feeding amount is 0.2ml/min, and the material is ethylene glycol EG; the reaction condition of the pipe A is that the gasification temperature is 200 ℃, the reaction temperature is 180-220 ℃, the pressure is 3.0-7.0 MPa, the molar ratio of hydrogen to ammonia to glycol is 6:8:1, and the flow rate of the hydrogen is 300ml/min; the reaction condition of the pipe B is that the gasification temperature is 220 ℃, the reaction temperature is 220-240 ℃ and the pressure is 3.0-7.0 MPa, and the gas phase outlet of the pipe A reactor directly enters the gasification feed inlet of the pipe B reactor; And the reactor B is provided with a condenser, the product passes through the condenser, and the liquid-phase product is separated by a separator.
  9. 9. The use according to claim 7, characterized in that the specific steps of the selective synthesis of diglycolamine, morpholine, dimorpholine ethyl ether applied to the continuous ammonification of the alcoholic hydroxyl groups of diethylene glycol, the cascade ring ammonification reaction are as follows: Grinding, tabletting, crushing and screening the Co-Mo 2 C@NC diatomic catalyst to obtain a 40-60 mesh small granular catalyst; The reactor adopts a fixed bed tubular reactor, two single pipes are connected in series, the inner diameter of each single pipe is 20mm, the length of each pipe is 300mm, independent sampling is carried out, and control parameters are set; Filling the catalyst in a constant temperature zone of a fixed bed reactor respectively, reducing for 6-12 hours at 100-300 ℃ by using hydrogen with the flow rate of 100-300 ml/min, cooling, and feeding diethylene glycol DEG for reaction by a high-pressure constant-flow pump; Feeding, wherein the feeding amount is 0.2ml/min, and the material is diethylene glycol DEG; The reaction condition of the pipe A is that the gasification temperature is 200 ℃, the reaction temperature is 180-220 ℃, the pressure is 3.0-7.0 MPa, the molar ratio of hydrogen to ammonia to diglycol is 6:8:1, and the flow rate of the hydrogen is 300ml/min; the reaction condition of the pipe B is that the gasification temperature is 220 ℃, the reaction temperature is 220-240 ℃ and the pressure is 3.0-7.0 MPa, and the gas phase outlet of the pipe A reactor directly enters the gasification feed inlet of the pipe B reactor; A. and the reactor B is provided with a condenser, the product passes through the condenser, and the liquid-phase product is separated by a separator.

Description

Preparation method and application of ammoniation heterogeneous interface regulation Co-Mo 2 C@NC diatomic catalyst Technical Field The invention belongs to the technical field of catalysts, and particularly relates to a preparation method and application of an ammonification heterogeneous interface regulation Co-Mo 2 C@NC diatomic catalyst. Background At present, the mass production of ammonia is widely carried out by a Haber Bosch process, and a catalyst which takes iron (gamma-Fe) as a main body is used to enable nitrogen and hydrogen in air to react at high temperature and high pressure. The metal molybdenum (Mo) is used as a catalyst by the companies of West Lin Renzhao and the like, such as the Ministry of light and the chemical products of the Japanese, and the synthetic speed is seven times of that of a gamma-Fe iron-based catalyst, and the use times are increased to be fifteen times before, and reach sixty thousand times. The ammonia is used as a nitrogen source raw material of fertilizer and protein, and plays a supporting role in people's diet and life. Ammonia and organic matter are catalytically aminated to synthesize organic amine, which is classified into seven kinds of aliphatic amine, alcohol amine, alicyclic amine, aromatic amine, naphthalene amine and other amine. The downstream application field is wide, and the industrial demand is large, so that the promotion of the development of the organic amine industry is important. Ethylene glycol and diethylene glycol are important raw materials for polyester products. In recent years, the national policy aims of greenization, high-end and intellectualization are achieved. With the continuous innovation of bioenergy and material technology. The biological glycol and diglycol productivity is continuously increased. In China, the traditional mode of ethylene glycol is two ways of petroleum ethylene method and coal-based process, and especially the new increase of ethylene glycol from coal-based process can be great. The ethylene glycol and the diethylene glycol are subjected to ammonification reaction to prepare various amine compounds. These compounds are widely used. Such as Diglycolamine (DGA), easy biodegradation, low bioaccumulation and high biostability, is used as a high-end electronic product such as polymer proton membrane, liquid crystal, microsphere and the like, morpholine is one of industrial important cyclic amines, a novel pesticide and raw materials of medicines, a gas absorbent, a synthetic herbicide, an environment-friendly solvent for artificial fibers, an antioxidant, a preservative, a slow-release and scale inhibitor and the like, dimorpholinodiethyl ether is used as an aqueous polyurethane curing agent, ethylenediamine is an important chemical raw material for producing pesticides, herbicides, fuels, curing agents and the like, piperazine is used as a medical intermediate for producing fluphenazine, qigong, piperazine citrate, levodropropizine, piperazine ferulate and the like, and hydroxypiperazine is used for synthesizing surfactants, medicines and pesticides, polyurethane curing agents and the like. In organic synthesis, monoatomic catalysts have been used in a wide range of applications. However, in general, a single-atom catalyst has only one active site, and the performance is limited, and the catalytic reaction including the ammonification and the cyclic amine, which have both selectivity and versatility, cannot be performed. Polymeric Carbon Nitride (CN) is an organic semiconductor material, and has a fibrous structure bonded together through hydrogen bonds, also called heterojunction (N-Pot), and a material for fixing metal atoms by using the polymeric Carbon Nitride (CN) has good catalytic performance. Disclosure of Invention The invention uses polymeric carbon nitride as a substrate to prepare the diatomic catalyst. Provides a preparation method and application of an ammoniation heterogeneous interface regulation Co-Mo 2 C@NC diatomic catalyst. The nano Co-Mo 2 C heterostructure is prepared through in-situ topological phase transition, is anchored on N-doped carbon (Co-Mo 2 C@NC), and cobalt (Co) and molybdenum (Mo) doped in a CN framework structure enter into an N-pot of a carbon nitride framework, and a new energy level is established, so that high heat conduction and high load are achieved, a rich heterogeneous interface is utilized, the space separation capacity of carriers is improved, mass transfer is increased, and the conversion rate, selectivity, separation efficiency and specific surface area of the catalyst are improved, and the catalyst further shows high catalytic activity. And the self-adaptive coordination is realized in the reaction process, and the universal performance is better. The catalyst obtained by the preparation method is used for ammonification synthesis of ethylene glycol and diethylene glycol to obtain aliphatic amine and cyclic amine with high added values, such as ethylenediamine, pip