阅读说明：本技术 用于氯代烃低温催化消除的Mn和Ba共促进的四氧化三钴催化剂及制备和应用 (Mn and Ba co-promoted cobaltosic oxide catalyst for low-temperature catalytic elimination of chlorohydrocarbon, and preparation and application thereof ) 是由 崔大祥 蔡婷 袁静 赵昆峰 童琴 于 2020-12-24 设计创作，主要内容包括：本发明公开一种用于氯代烃低温催化消除的Mn和Ba共促进的四氧化三钴催化剂及制备和应用。该催化剂是Mn和Ba共促进的Co-3O-4,其中Ba与Co的摩尔比为1：50,Mn与Co的比为1：3,形成的Mn-xCo-(3-x)O-4为主要活性组分,BaCO-3为催化剂助剂。催化剂采用两步共沉淀法制备,沉淀剂分别为氨水和Na-2CO-3。该催化剂对氯乙烯、氯本和二氯苯均具有较好的催化效果。该催化剂制备方法简单,Mn和Ba共修饰可以有效提高Co-3O-4催化剂对于氯代烃的吸附活化和氧化,特别适用于低温催化燃烧消除氯代挥发性有机物。(The invention discloses a CoO (CoO) catalyst promoted by Mn and Ba for low-temperature catalytic elimination of chlorohydrocarbon, and preparation and application thereof. The catalyst is Co promoted by Mn and Ba 3 O 4 Wherein the molar ratio of Ba to Co is 1: 50, Mn to Co ratio of 1: 3, Mn formed x Co 3‑x O 4 As a main active component, BaCO 3 Is a catalyst auxiliary agent. The catalyst is prepared by a two-step coprecipitation method, and the precipitating agents are ammonia water and Na respectively 2 CO 3 . The catalyst has good catalytic effect on vinyl chloride, chloroben and dichlorobenzene. The catalyst has simple preparation method, and Co can be effectively improved by Co-modifying Mn and Ba 3 O 4 The catalyst is used for the adsorption activation and oxidation of chlorinated hydrocarbon, and is especially suitable for low-temperature catalysisBurning to eliminate volatile organic chloride.)

1. A Co-promoted cobaltosic oxide catalyst for low-temperature catalytic elimination of chlorinated hydrocarbon is characterized in that Co Co-promoted by Mn and Ba₃O₄Wherein the molar ratio of Ba to Co is 1: 50, the molar ratio of Mn to Co is 1: 3, Mn formed_xCo_3-xO₄As a main active component, BaCO₃Is a catalyst auxiliary agent.

2. A process for the preparation of Mn and Ba Co-promoted tricobalt tetroxide catalyst for the low temperature catalytic elimination of chlorinated hydrocarbons as claimed in claim 1, characterized by the fact that it is prepared by a two-step Co-precipitation method by the Co-precipitation of Co₃O₄The crystal lattice and the surface of the catalyst are regulated and controlled to promote the adsorption, activation and oxidation of the chlorine-containing volatile organic compounds, and the precipitating agents are respectively ammonia water and Na₂CO₃The method comprises the following steps:

weighing 14.55g of cobalt nitrate hexahydrate, dissolving in 200ml of deionized water, respectively adding 0.29g of barium nitrate hexahydrate and 5.96g of 50% manganese nitrate solution, stirring uniformly in a water bath at 90 ℃, then adding ammonia water to adjust the pH to 9, continuously dropwise adding sodium carbonate to increase the pH to 10, filtering and washing precipitates, drying overnight at 100 ℃, and roasting for 3 hours at 500 ℃ in the air to obtain the catalyst.

3. The use of the Mn and Ba co-promoted tricobalt tetroxide catalyst for the low-temperature catalytic elimination of chlorinated hydrocarbons as defined in claim 1 in the catalytic combustion of various chlorine-containing volatile organic compounds of vinyl chloride, chlorobene and dichlorobenzene with a treatment concentration of 500-3000ppm and a space velocity of 15,000-30,000 ml-g^–1·h^–1。

Technical Field

The invention belongs to the technical field of catalytic environmental protection, and particularly relates to a Mn and Ba co-promoted cobaltosic oxide catalyst for low-temperature catalytic elimination of chlorinated hydrocarbons, and preparation and application thereof.

Background

In recent years, environmental pollution has become a hot issue for international and domestic social concerns and discussions. chlorine-Containing Volatile Organic Compounds (CVOCs) are widely used as a typical one of VOCs in the fields of industry, agriculture, agricultural chemicals, medicine, organic synthesis, and the like. They enter the environment through volatilization, leakage, discharge and other ways in the using process, can cause the damage of the ozone layer, photochemical smog and global warming, and the C VOCs are difficult to biodegrade and easy to accumulate in the organism, and have strong carcinogenic, teratogenic and mutagenic 'triple-causing' effects. Therefore, the method has attracted great attention of researchers. Among the 129 environmental pollutants published in the united states in 1977, 60 are halogenated hydrocarbons and their derivatives, and are listed by the united states national environmental protection agency as one of the 17 classes of highly toxic chemicals for emission reduction. On the "black list" of exhaust gas published by the european union, the first place to be listed is the halides and their derivatives. In 68 priority control pollutants proposed in 1989, 25 pollutants are also chlorine-containing volatile organic compounds. In view of the harm of the C VOCs to human health and the environment, technical research on the treatment of the C VOCs exhaust gas is being conducted around the world, and various treatment methods are being explored, among which the more mature techniques are incineration, catalytic combustion, condensation, biological, catalytic reduction, photochemical oxidation, ultraviolet photolysis, absorption, adsorption, and the like.

The catalyst for catalytic combustion of VOCs at present is mainly a noble metal catalyst, but the cost of the noble metal catalyst is still relatively high, and the stability is relatively poor. Co₃O₄Is one of the transition metals which are currently used for removing the highest activity of VOCs. But its use in catalytic combustion of chlorine-containing volatile organics often produces polychlorinated by-products. And pure Co₃O₄Particle growth usually occurs during the manufacturing process. Therefore, the invention discloses Co Co-promoted by Mn and Ba₃O₄On the one hand, the redox capacity is increased by doping the crystal lattice with Mn and, on the other hand, by BaCO₃To Co₃O₄The surface modification of (2) promotes the activated adsorption of the chlorinated hydrocarbon.

Disclosure of Invention

The invention aims to provide a Mn and Ba co-promoted cobaltosic oxide catalyst for low-temperature catalytic elimination of chlorinated hydrocarbons.

Yet another object of the present invention is to: provides a preparation method of the Mn and Ba co-promoted cobaltosic oxide catalyst product for low-temperature catalytic elimination of chlorinated hydrocarbon.

Yet another object of the present invention is to: provides an application of the product.

The purpose of the invention is realized by the following scheme: a Co-promoted cobaltosic oxide catalyst for low-temperature catalytic elimination of chlorinated hydrocarbon is characterized in that Co Co-promoted by Mn and Ba₃O₄Wherein the molar ratio of Ba to Co is 1: 50, Mn to Co ratio of 1: 3, Mn formed_xCo_3-xO₄As a main active component, BaCO₃Is a catalyst auxiliary agent.

The invention provides a preparation method of Mn and Ba Co-promoted cobaltosic oxide catalyst for low-temperature catalytic elimination of chlorohydrocarbon, which is characterized in that the catalyst is prepared by adopting a two-step coprecipitation method and Co is subjected to₃O₄The crystal lattice and the surface of the catalyst are regulated and controlled to promote the adsorption, activation and oxidation of the chlorine-containing volatile organic compounds, and the precipitating agents are respectively ammonia water and Na₂CO₃The method comprises the following steps:

weighing 14.55g of cobalt nitrate hexahydrate, dissolving the cobalt nitrate hexahydrate in 200ml of deionized water, respectively adding 0.29g of barium nitrate hexahydrate and 5.96g of 50% manganese nitrate solution, uniformly stirring the mixture in a water bath at 90 ℃, then adding ammonia water into the mixture to adjust the pH value to 9, continuously dropwise adding sodium carbonate to increase the pH value to 10, filtering and washing precipitates, drying the precipitates at 100 ℃ overnight, and roasting the precipitates for 3 hours at 500 ℃ in the air to obtain the catalyst.

The invention provides a Mn and Ba co-promoted cobaltosic oxide catalyst for low-temperature catalytic elimination of chlorinated hydrocarbon, which is applied to catalytic combustion of a plurality of chlorine-containing volatile organic compounds such as chloroethylene, chlorobene and dichlorobenzene, and has the treatment concentration of 500-3000ppm and the space velocity of 15,000-30,000 ml-g^–1·h^–1。

The catalysts of the examples are used in vinyl chloride catalysisChemical combustion, the evaluation of the activity of the catalyst used for the catalytic combustion of vinyl chloride is carried out in a fixed bed microreactor (a quartz tube with the inner diameter of 3 mm), the dosage of the catalyst is 200mg, and the temperature is automatically controlled by a K-type thermocouple. The chloroethylene standard gas is mixed with air and enters a reactor for combustion. The total flow is controlled by a mass flow meter, the concentration of chloroethylene is 0.05 vol%, air is used as carrier gas, the concentration of oxygen is 10%, the reaction temperature is 140-. The relationship between the conversion of vinyl chloride and the reaction temperature is shown in Table 1, wherein T_90%The reaction temperatures required for a conversion of 90% were respectively obtained.

The catalyst has good catalytic effect on vinyl chloride, chloroben and dichlorobenzene. The catalyst has simple preparation method, and Co can be effectively improved by Co-modifying Mn and Ba₃O₄The catalyst is used for the adsorption, activation and oxidation of chlorinated hydrocarbon, and is particularly suitable for eliminating chlorinated volatile organic compounds by low-temperature catalytic combustion.

Based on the existing research, Mn and Co are adopted to react with Co₃O₄Co-modifying by subjecting Co₃O₄The crystal lattice and the surface of the chlorine-containing volatile organic compound are regulated and controlled, and the adsorption, activation and oxidation of the chlorine-containing volatile organic compound are promoted.

The invention provides Mn and Ba Co-promoted Co for low-temperature catalytic elimination of chlorohydrocarbon₃O₄A catalyst. The catalyst has good catalytic activity on the chlorine-containing volatile organic compounds, and has good application prospect in the aspect of removing the chlorine-containing volatile organic compounds.

Detailed Description

Examples

Mn and Ba Co-promoted cobaltosic oxide catalyst for low-temperature catalytic elimination of chlorohydrocarbon, namely Mn and Ba Co-promoted Co₃O₄Wherein the molar ratio of Ba to Co is 1: 50, the molar ratio of Mn to Co is 1: 3, Mn formed_xCo_3-xO₄As a main active component, BaCO₃Is a catalyst auxiliary agent. Prepared by a two-step coprecipitation method through the reaction of Co₃O₄The crystal lattice and the surface of the catalyst are regulated and controlled to promote the adsorption, activation and oxidation of the chlorine-containing volatile organic compounds, and the precipitating agents are respectivelyAmmonia and Na₂CO₃The preparation method comprises the following steps:

weighing 14.55g of cobalt nitrate hexahydrate, dissolving the cobalt nitrate hexahydrate in 200ml of deionized water, respectively adding 0.29g of barium nitrate hexahydrate and 5.96g of 50% manganese nitrate solution, stirring the mixture uniformly in a water bath at 90 ℃, then adding ammonia water into the mixture to adjust the pH value to 9, continuously dropwise adding sodium carbonate to adjust the pH value to about 10, filtering and washing the precipitate, drying the precipitate overnight at 100 ℃, and roasting the precipitate for 3 hours at 500 ℃ in the air to obtain the catalyst.

Application example 1

The catalyst obtained in the example is used for the catalytic combustion of vinyl chloride, and the activity evaluation of the catalyst used for the catalytic combustion of vinyl chloride is carried out in a fixed bed microreactor (a quartz tube with an inner diameter of 3 mm), the dosage of the catalyst is 200mg, and the temperature is automatically controlled by a K-type thermocouple. The chloroethylene standard gas is mixed with air and enters a reactor for combustion. The total flow is controlled by a mass flow meter, the concentration of chloroethylene is 0.05 vol%, air is used as carrier gas, the concentration of oxygen is 10%, the reaction temperature is 140-. The relationship between the conversion of vinyl chloride and the reaction temperature is shown in Table 1, wherein T_90%The reaction temperatures required for a conversion of 90% were respectively obtained.

Application example 2

The catalyst obtained in the example is used for chlorobenzene catalytic combustion, and the activity evaluation of the catalyst used for chlorobenzene catalytic combustion is carried out in a fixed bed microreactor (a quartz tube with the inner diameter of 3 mm), the dosage of the catalyst is 100mg, and the temperature is automatically controlled by a K-type thermocouple. Chlorobenzene is brought into the reaction system by nitrogen by a trace sample injection pump. The total flow is controlled by a mass flow meter, the concentration of chlorobenzene is 0.1 vol%, air is used as carrier gas, the concentration of oxygen is 10%, the reaction temperature is 140-. The relationship between the chlorobenzene conversion and the reaction temperature is shown in Table 1, wherein T_90%The reaction temperatures required for a conversion of 90% were respectively obtained.

Application example 3

The catalyst obtained in the example was used for catalytic combustion of dichlorobenzene, and the activity of the catalyst used for catalytic combustion of dichlorobenzene was evaluated in a fixed-bed microreactor (quartz having an inner diameter of 3 mm)Tube), the amount of catalyst used was 100mg, and the temperature was automatically controlled using a type K thermocouple. Dichlorobenzene is brought into the reaction system by nitrogen by a trace sample injection pump. The total flow is controlled by a mass flow meter, the concentration of chlorobenzene is 0.3 vol%, air is used as carrier gas, the concentration of oxygen is 10%, the reaction temperature is 140-. The relationship between the conversion of dichlorobenzene and the reaction temperature is shown in Table 1, wherein T is_90%The reaction temperatures required for a conversion of 90%, respectively:

from the catalytic oxidation activity results, the catalyst prepared by the invention has good catalytic activity on vinyl chloride, chlorobenzene and dichlorobenzene, and has a certain application prospect on the removal of CVOCs.