CN102773103A - Catalyst for deeply removing CO at low temperature as well as preparation and activation methods and application thereof - Google Patents

Abstract

The present invention relates to a kind of catalyst and its preparation method, activation method and application of low-temperature deep CO removal, the catalyst is composed of CuO, ZnO, ZrO ₂ composite oxide CuO-ZnO-ZrO ₂ composite catalyst, the total weight of the catalyst Calculated as 100%, CuO: 50-90wt%; ZnO: 5-40wt%; ZrO ₂ : 5-40wt%, wherein the copper-containing component has a reduction degree of 70-80%, and the reduction degree is based on the metal copper It is expressed as a weight ratio to the sum of metallic copper and copper oxide as CuO. Compared with the prior art, the catalyst of the present invention is suitable for removing carbon monoxide in liquid or gaseous hydrocarbons and/or inert gases, and has high activity at low temperature (0-50°C), high removal depth (≤20ppb), and long service life It has the characteristics of simple preparation process and can reduce the cost of catalyst preparation.

Description

Catalyst for deep removal of CO at low temperature, preparation method, activation method and application thereof

technical field

The invention relates to a catalyst for removing CO from hydrocarbon or inert gas materials, its preparation method, activation method and application. The invention is especially suitable for the removal of trace amounts of CO in α-olefins and saturated hydrocarbons in the field of petrochemical industry, or the preparation of high-purity gases (such as nitrogen, helium, argon, etc.) in the electronic industry.

Background technique

In various industrial fields, the presence of trace carbon monoxide is often harmful to the reaction system and needs to be removed as an impurity. With the development of polyolefin technology, highly active polyolefin catalysts are very sensitive to poisons, and polyolefin raw materials are required to be "polymerization grade" olefins. Specifically, the carbon monoxide impurity in olefin raw materials does not exceed 30ppb. Typical is the propylene polymerization process. With the development of propylene polymerization catalysts, the polymerization reaction is extremely sensitive to various impurities in the reaction system. Among them, CO can enter the polymerization chain and affect the orientation ability of the catalyst; it can also terminate the polymerization chain and reduce the catalyst’s active. In the electronics industry, especially in the manufacture of semiconductor components, "electronically pure" high-purity gas is required, and the carbon monoxide impurity contained in it is required to be lower than several ppb.

In the prior art, methods for removing trace amounts of CO in olefins include distillation and catalytic oxidation. However, installing a distillation column is capital costly, expensive to operate, and does not reduce CO levels to "polymer grade" levels. The low-temperature catalytic oxidation of CO is the most direct, simple, cheap and effective method and means to eliminate CO. This method is very attractive for industrial implementation due to its advantages of simple operation, low cost, and deep removal. Since the domestic polypropylene process is mostly a liquid phase process, the low-temperature CO removal performance of the catalyst is of great significance, otherwise it will inevitably cause problems such as increased device process, increased equipment investment, and inconvenient operation. However, most catalysts are suitable for high reaction temperatures and can only be used in gas phase polymerization processes.

The catalysts that were earlier applied to the removal of trace carbon monoxide were noble metal catalysts, typically Au, Pd, Pt, etc., especially Au catalysts have good low-temperature activity, and carbon monoxide oxidation reaction can occur at low temperature or even room temperature. For example, US5662873 discloses a catalyst whose main component is Au, Ag or both, or at least one of platinum group elements, which can react trace amounts of _H2 and CO in inert gas with _O2 at 80-130°C Keep H ₂ below 10ppb and CO below 5ppb. CN101371984A discloses a catalyst in which the main active _component Au is supported on a carrier such as diatomaceous earth, which can oxidize trace amounts of CO in olefins or saturated hydrocarbon streams to CO2 at room temperature to 70°C, but requires the removal of The CO content in the stream is less than 5ppm. However, such catalysts use noble metals such as Au, Pd, and Pt, which are expensive and unfavorable for industrial applications.

Non-precious metal catalysts such as copper-based catalysts have been widely used in industrial trace carbon monoxide removal. Typical Hopcalite catalysts used in gas masks are copper-manganese catalysts and have high activity for the reaction of carbon monoxide and oxygen. However, the catalyst is very sensitive to water and is easily deactivated in the presence of water vapor, and oxygen is required exist.

US5625116 discloses a method for deep removal of CO from α-olefins and saturated hydrocarbons to below 0.03ppm. The catalyst is a copper-chromium catalyst. The catalyst preparation process uses chromium salts, which causes serious environmental pollution and is not suitable for large-scale industrial applications. .

WO95/21146 discloses a catalyst containing copper or copper manganese, which simultaneously removes carbon monoxide and arsenic from hydrocarbon materials, and can remove carbon monoxide to less than 1 ppb at a low temperature to 40°C. However, this catalyst is more suitable for treating CO in materials. When the content of CO is tens of ppb, when the content of CO in the material reaches the ppm level, the removal depth value becomes larger, and it can only be used for about one month.

CN1044599C discloses a copper-zinc catalyst (that is, the BR9201 catalyst that has been used in industry in China), which removes CO from α-olefins and saturated hydrocarbons only to 0.1ppm; for the deep removal of CO, the catalyst still needs to be improved.

CN1681583A and US2005/0241478 disclose a copper-zinc-zirconium adsorption material to remove carbon monoxide from the material flow. The adsorption material can only remove carbon monoxide by adsorption. More importantly, there are no examples to clarify the reaction conditions and the removal of trace CO. In addition to the depth, the service life of the adsorbent is also unclear.

CN101642707A and CN101462057A disclose a two-component copper-zirconium catalyst or a copper-zirconium-containing three-component catalyst, which can remove propylene containing 5 ppm CO to below 30 ppb in gas and liquid phases. However, what is disclosed is the preparation of the catalyst precursor, and there is no clear and suitable activation method, which is an essential key technology in the preparation of this type of catalyst.

Therefore, it is necessary to develop a low-temperature, high-activity, high-stability, low-cost, and easy-to-industrialize catalyst for the deep purification of trace carbon monoxide, and to study its activation method and reaction process, which is of great significance to industrial applications such as polyolefins.

Contents of the invention

The object of the present invention is to provide a low-cost, easy-to-industrialize catalyst for deep removal of CO at low temperature and its preparation method, activation method and application in order to overcome the above-mentioned defects in the prior art.

The object of the present invention can be achieved by the following technical solutions: a catalyst for deep removal of CO at low temperature, characterized in that, the catalyst is composed of CuO, ZnO, _ZrO Composite oxide CuO-ZnO- _ZrO Composite catalyst, Based on the total weight of the catalyst as 100%, CuO: 50-90wt%; ZnO: 5-40wt%; _ZrO2 : 5-40wt%, wherein the copper-containing component has a reduction degree of 70-80%, and the reduction degree It is represented by the weight ratio of metallic copper to the sum of metallic copper and copper oxide calculated as CuO.

A method for preparing a catalyst for deep removal of CO at low temperature, characterized in that the method comprises the following steps:

(1) Preparation of metal salt and alkali solution: take a certain amount of copper salt, zinc salt, zirconium salt and water, and mix it into copper salt, zinc salt and zirconium salt solution with concentration of 0.2～3mol/L respectively, Fully stir until uniform to obtain a mixed salt solution, calculated as CuO, ZnO and _ZrO2 , wherein CuO50-90wt%, ZnO5-40wt%, _ZrO2 5-40wt%; weigh alkali and water, and prepare a concentration of 0.2-3mol /L alkaline solution;

(2) Precipitation: the mixed salt solution and alkali solution prepared in step (1) are mixed and reacted by co-current method or sequential addition method, and the precipitate obtained is the catalyst precursor;

(3) Aging: fully stir the catalyst precursor obtained in step (2), and age for 30-240 minutes at a temperature of 60-85°C;

(4) Repeatedly washing and centrifuging the precipitate obtained in step (3) and drying at 110° C. for 12-16 hours;

(5) Calcining the dried product in step (4) at 300-600° C. for 6 hours to obtain a CuO-ZnO-ZrO ₂ composite catalyst.

The copper salt described in step (1) comprises one or more in copper nitrate, copper sulfate, copper acetate or cupric chloride, and described zinc salt comprises one or both in zinc nitrate or zinc sulfate, so The zirconium salt includes one or more of zirconium nitrate, zirconium sulfate, zirconium oxychloride or zirconium acetate; the alkali includes one of sodium carbonate, sodium bicarbonate, sodium hydroxide, ammonia or ammonium carbonate or several.

The copper salt is copper nitrate, the zinc salt is zinc nitrate, the zirconium salt is zirconium nitrate, and the alkali is ammonium carbonate.

The parallel flow method described in step (2) is: add the mixed salt solution and the alkali solution into the container at the same time, react at a temperature of 50-85° C., the pH value of the precipitation is 6.0-8.0, and the added amount of the mixed salt solution and the alkali solution is The molar ratio is 1:1;

The sequential addition method is to add the alkali solution into the salt solution, react at a temperature of 50-85° C., and the pH value of the titration end point is 6.0-8.0.

The temperature of the roasting described in step (5) is 320-500°C.

The CuO-ZnO- _ZrO2 composite catalyst obtained in step (5) can be mixed evenly with the binder before use, after being rolled and pressed into tablets, sieved, and to be activated; the binder is a variety of catalysts available for molding. Adhesive, the addition amount of the adhesive is 0.1-5wt%.

The binder is graphite.

In the preparation method of the catalyst of the present invention, the alkaline solution to be added dropwise is preferably an ammonium carbonate solution, and the catalyst prepared by the M(NO ₃ )x co-precipitation method using ammonium carbonate has a good copper dispersion of the active component and a low content of the surface active component. High, with good redox performance, so it is better to use ammonium carbonate to M(NO ₃ )x co-precipitation method to prepare CO removal catalyst.

In the preparation method of the catalyst of the present invention, the precipitation mode of the salt solution and the alkali solution is preferably the parallel flow method, and the catalyst prepared by the parallel flow method has a uniform crystal component, and _ZrO exists as an amorphous component, and the active component Copper dispersion is high.

A method for activating a catalyst for deep removal of CO at low temperature, characterized in that the method is: heating the catalyst to 120-220°C in a flow of 1-10% H ₂ /inert gas, and then reducing the temperature for 1-12 hours .

The reduction temperature is preferably 160°C, the reduction time is preferably 3 to 6 hours, and the reduction degree of the catalyst after activation is 70 to 80%, and the reduction degree is based on metal copper, metal copper and copper oxide calculated as CuO The weight ratio of the sum is expressed.

For the catalyst of the present invention, reduction and activation is an essential step. If the reduction is improper, it will cause sintering of the catalyst or fail to reach a better reduction state. If the catalyst with the best potential is not activated well, the activity will not be high, and even Causes the termination of the reaction run. Cu ²⁺ in the catalyst is partially reduced to Cu ⁺ , Cu, and activated to a certain degree of reduction. Described degree of reduction is represented by the weight ratio of the sum of metallic copper and metallic copper and the copper oxide of CuO:

metal copper

Copper metal + copper oxide as CuO

The degree of reduction of CuO in CuO-ZnO- _ZrO2 catalysts can be determined by three methods: (1) the consumption of _H2 in _H2 -TPR; (2) the weight of _O2 lost in thermogravimetry; (3) the weight of O2 in XRD The amount of CuO reduction and the amount of Cu generation were detected.

In the catalyst activation method of the present invention, the reduction temperature is preferably 160°C. Different reduction temperatures can change the distribution and valence state of active Cu species on the catalyst surface. A reduction temperature of 160°C can partially reduce the active Cu species, and the suitable reduction degree is 70-80%.

An application of a catalyst for deep removal of CO at low temperature, characterized in that the catalyst is applied to remove trace amounts of CO in hydrocarbons and/or inert gases. Under the condition ^{of ~5MPa, the material containing trace amount of CO is contacted with the catalyst, the space velocity of liquid phase is 0.1 ~ 100h -1 ,} the space velocity of gas phase is 10 ~ 100000h ^-1 , and the CO in the material is removed to make the content ≤ 20ppb.

The catalyst converts CO into CO ₂ , and the material containing a small amount of CO includes α-olefins, saturated hydrocarbons, gas phase or liquid phase of styrene or N ₂ , and the content of CO in the material containing a small amount of CO is 0.02ppm-1000ppm; when the material containing a trace amount of CO is liquid hydrocarbon, the reaction temperature is 0-50°C.

The content of CO in the material containing trace amount of CO is preferably 0.02ppm-100ppm.

The catalyst for removing trace carbon monoxide in hydrocarbons and or inert gases of the present invention and its preparation method, activation and application have the following advantages compared with the prior art:

1. According to the preparation method of the catalyst of the present invention, the prepared catalyst has a large content of active components and a high degree of dispersion, which greatly improves the depth of removal of CO by the catalyst, and can remove CO as low as 20 ppb within a relatively large content range; At the same time, the preparation steps are simple, the preparation cost of the catalyst is reduced, and the industrial production is easy.

2. The catalyst of the present invention has high activity at low temperature and can be operated at low temperature or even normal temperature (0-50° C.), and is especially suitable for the removal of hydrocarbons in the liquid phase state, which can shorten the device process and reduce equipment investment.

3. The catalyst activation method of the present invention has a good activation effect, and effectively controls the active components of the catalyst in a better reduction state, so that the catalyst precursor has better CO removal performance after activation.

Detailed ways

Examples 1-7

Preparation of CuO/ZnO/ZrO ₂ Composite Oxide Catalyst Precursor

According to the ratio: CuO:ZnO:ZrO ₂ =x:y:(1-xy), the raw materials are weighed, and the values of x and y are weight percentages, as shown in Table 1.

Prepare Cu, Zn, Zr metal nitrates into solutions of a certain concentration, and mix them evenly under stirring; through a certain precipitation method, precipitate with ammonium carbonate solution under stirring and a certain temperature, after the precipitation is completed, adjust the pH value of the system ; Aging the obtained catalyst precursor at a certain temperature, fully stirring; taking out the solid product, washing it repeatedly with deionized water at a certain temperature, centrifuging, and placing it in a drying oven at 110°C for overnight drying; at 350-550°C Calcined for 6.0 hours and cooled to room temperature to obtain the calcined CuO/ZnO/ZrO _composite oxide product;

The precipitation methods include co-current method and sequential addition method. The co-current method is: add the mixed salt solution and alkali solution into the container at the same time, and react at a temperature of 50-85°C. The pH value of the precipitation is 6.0-8.0, and the mixed salt solution The molar ratio of solution and alkaline solution addition is 1: 1;

The sequential addition method is to add the alkali solution into the salt solution, react at a temperature of 50-85° C., and the pH value of the titration end point is 6.0-8.0.

Comparative example 1~2

According to the ratio: CuO:ZnO=x:(1-x), the raw materials were weighed, and the value of x was weight percent, as shown in Table 1.

After preparing the nitrate of Cu and/or Zn metal into a solution with a certain concentration, mix it evenly under stirring; carry out precipitation with alkali solution under stirring and a certain temperature through a certain precipitation method, and adjust the pH value of the system after the precipitation is completed; Aging the obtained catalyst precursor at a certain temperature, fully stirring; taking out the solid product, washing it repeatedly with deionized water at a certain temperature, centrifuging, placing it in a drying oven and drying it at 110°C with air flow overnight; roasting at 350-550°C After 6.0 hours, cool to room temperature to obtain the comparison sample;

Table 1 Catalyst Preparation Experimental Results

The XRD test shows that _ZrO in the obtained Example 1, Example 3, and Examples 5-7 exists in an amorphous form. Take Example 5 as an example, see Table 2.

Table 2 Example 5XRD data

It is confirmed from Table 1 that the composition, precipitating agent, precipitation method and calcination temperature of the composite oxide are different, and the crystal form of the synthesized product, the dispersion degree of copper particles and the reducibility property are different. By controlling the optimal preparation factors, CuO/ZnO/ZrO ₂ composite oxide catalysts with higher active copper dispersion and easy reduction can be synthesized, thus having better CO removal performance.

Embodiment 8～11

Activation of CuO/ZnO/ZrO ₂ Composite Oxide Catalysts

After compressing and crushing the composite oxide catalyst prepared in Embodiment 5, sieve molecular sieve particles with a particle size of 80-100 mesh for activation.

The activation adopts a fixed bed catalytic reaction device, and the reactor is a stainless steel tube. The catalyst prepared in Example 5 is reduced and activated. The process conditions used for activation are: catalyst loading 3mL, activation temperature is 100-200 ° C, and the pressure is normal pressure. The activation time is 4 hours, the raw material is 10% H ₂ /N ₂ , and the volume space velocity is 4000 hours ^-1 . After characterization, the effects of different activation temperatures on the reduction degree of the catalyst are shown in Table 3.

Table 3 activation results

Example 12

Evaluation of Low Temperature Removal of Trace CO in Hydrocarbons

A fixed-bed catalytic reaction device is adopted, and the reactor is a stainless steel tube. The catalysts of Examples 8 to 11 are respectively evaluated for CO removal performance. The process conditions used for the evaluation are: the catalyst loading is 3 mL, the reaction temperature is 40 ° C, and the reaction pressure is 3MPa, the raw material is liquid phase propylene containing 20ppm CO, and the liquid phase space velocity is 8.0 h ^-1 . After the product was decompressed, it was analyzed online with a helium ion detector GC9560, and the evaluation results are shown in Table 4.

Table 4 The results of trace CO removal in liquid phase propylene

Example 13

Stability Evaluation of Low Temperature Removal of Trace CO in Hydrocarbons

Using a fixed-bed catalytic reaction device, the reactor is a stainless steel tube, and the catalyst in Example 10 is evaluated for CO removal stability performance. The process conditions used for the evaluation are: the catalyst loading is 3 mL, the reaction temperature is 40 ° C, and the reaction pressure is 3MPa, the raw material is liquid phase propylene containing 20ppm CO, and the liquid phase space velocity is 8.0 h ^-1 . After the product was decompressed, it was analyzed online with a helium ion detector GC9560.

CO can be removed as low as ≤20ppb, continuous operation for 2 months, and the catalyst has good stability.

Example 14

A preparation method of a catalyst for deep removal of CO at a low temperature, the method comprising the following steps:

(1) Preparation of metal salt and alkali solution: Weigh a certain amount of copper sulfate, zinc sulfate, zirconium sulfate and water, and mix them into a salt solution with a concentration of 0.5mol/L respectively, and stir well until uniform to obtain a mixed salt solution , in terms of CuO, ZnO and _ZrO2 , wherein CuO 50wt%, ZnO 40wt%, _ZrO2 10wt%; take sodium bicarbonate and water, and prepare a sodium bicarbonate solution with a concentration of 0.5mol/L;

(2) Precipitation: Add the mixed salt solution and alkali solution prepared in step (1) into the container at the same time, and react at a temperature of 50°C. The pH value of the precipitate is 6.0 to 8.0. The molar ratio of the amount of mixed salt solution and alkali solution 1:1;

(3) Aging: Fully stir the catalyst precursor obtained in step (2), and age for 240 minutes at a temperature of 60°C;

(4) Repeatedly washing and centrifuging the precipitate obtained in step (3) and drying at 110° C. for 12 hours;

(5) Calcining the dried product in step (4) at 300° C. for 6 hours to obtain a CuO-ZnO-ZrO ₂ composite catalyst.

Gained CuO-ZnO-ZrO _Composite catalyst can be uniformly mixed with binder before use, after being rolled and pressed into tablets, sieved, and to be activated; the binder is graphite, and the addition of graphite is 0.5wt% .

The obtained catalyst was heated to 120° C. in a 1% H ₂ /inert gas flow, and then kept at the same temperature for reduction for 12 hours. The degree of reduction of the catalyst after activation is 70%, and the method for measuring the degree of reduction is: consumption of H ₂ in H ₂ -TPR;

The activated catalyst is applied to remove trace CO in hydrocarbons and/or inert gases. The specific method is: at a temperature of 0°C and a reaction pressure of 0.1 MPa, the α-olefin containing trace CO and the catalyst phase contact, the gas phase space velocity is 5000h ^-1 , and the CO in the material is removed to make the content ≤ 20ppb.

Example 15

A preparation method of a catalyst for deep removal of CO at a low temperature, the method comprising the following steps:

(1) Preparation of metal salt and alkali solution: Weigh a certain amount of copper acetate, copper sulfate, copper nitrate, zinc sulfate, zinc nitrate, zirconium nitrate, zirconium sulfate, zirconium oxychloride, zirconium acetate and water, and prepare respectively The salt solution containing Cu ²⁺ concentration of 2mol/L, Zn ²⁺ concentration of 2mol/L, and Zr ²⁺ concentration of 2mol/L is mixed afterward, fully stirred until uniform to obtain a mixed salt solution, and CuO, ZnO and ZrO ₂ Calculate, wherein CuO90wt%, ZnO5wt%, _ZrO2 5wt%; Weigh sodium hydroxide and water, be mixed with the sodium hydroxide solution that concentration is 2mol/L;

(2) Precipitation: Add the sodium hydroxide solution prepared in step (1) into the mixed salt solution, and react at a temperature of 85° C., and the pH value at the titration end point is 6.0 to 8.0;

(3) Aging: fully stir the catalyst precursor obtained in step (2), and age for 30 minutes at a temperature of 85°C;

(4) Repeatedly washing and centrifuging the precipitate obtained in step (3) and drying at 110° C. for 16 hours;

(5) Calcining the dried product in step (4) at 600° C. for 6 hours to obtain a CuO-ZnO-ZrO ₂ composite catalyst.

The obtained CuO-ZnO-ZrO ₂ composite catalyst can be uniformly mixed with a binder before use, and after being rolled, pressed into tablets, sieved, and then activated; the binder is graphite, and the amount of graphite added is 2 wt%.

The obtained catalyst was heated to 220° C. in a flow of 10% H ₂ /inert gas, then kept at constant temperature, and then reduced for 1 h. The reduction degree of the catalyst after activation is 80%.

The degree of reduction of CuO in CuO-ZnO- _ZrO2 catalysts can be determined by the following method: (2) The weight lost by _O2 in thermogravimetry.

The activated catalyst is applied to remove trace CO in hydrocarbons and/or inert gases. The specific method is: at a temperature of 150° C. and a reaction pressure of 0.1 MPa, styrene containing trace CO is mixed with the catalyst Contact, the gas phase space velocity is 100000h ^-1 , and the CO in the material is removed to make the content ≤ 20ppb.

Example 16

A preparation method of a catalyst for deep removal of CO at a low temperature, the method comprising the following steps:

(1) Preparation of metal salt and alkali solution: Weigh a certain amount of copper acetate, zinc sulfate, zirconium acetate and water, respectively prepare a concentration of 0.2mol/L salt solution and mix, fully stir until uniform, to obtain a mixed salt solution , in terms of CuO, ZnO and _ZrO2 , wherein CuO80wt%, ZnO10wt%, _ZrO210wt %; take sodium hydroxide, ammonia and water, and prepare an alkali solution with an OH ^- concentration of 0.2mol/L;

(2) Precipitation: Add the alkali solution prepared in step (1) into the mixed salt solution, react at a temperature of 85° C., and the pH value at the titration end point is 6.0 to 8.0;

(3) Aging: Fully stir the catalyst precursor obtained in step (2), and age for 120 minutes at a temperature of 80°C;

(4) Repeatedly washing and centrifuging the precipitate obtained in step (3) and drying at 110° C. for 13 hours;

(5) Calcining the dried product in step (4) at 400° C. for 6 hours to obtain a CuO-ZnO-ZrO ₂ composite catalyst.

Gained CuO-ZnO-ZrO _Composite catalyst can be mixed evenly with binder before use, after being rolled and pressed into tablets, sieved, to be activated; described binder is graphite, and the addition of graphite is 0.1wt% .

The obtained catalyst was heated to 220° C. in a flow of 10% H ₂ /inert gas, then kept at constant temperature, and then reduced for 1 h. The reduction degree of the catalyst after activation is 70%.

The degree of reduction of CuO in CuO-ZnO- _ZrO2 catalysts can be determined by the following methods: the amount of CuO reduction and the amount of Cu generation detected in XRD.

The activated catalyst is applied to remove trace CO in hydrocarbons and/or inert gases. The specific method is: at a temperature of 50° C. and a reaction pressure of 5.0 MPa, styrene containing trace CO is mixed with the catalyst Contact, the liquid phase space velocity is 0.1h ^-1 , and the CO in the material is removed to make the content ≤ 20ppb.

Example 17

A preparation method of a catalyst for deep removal of CO at a low temperature, the method comprising the following steps:

(1) Preparation of metal salt and alkali solution: take a certain amount of copper acetate, zinc sulfate, zirconium acetate and water, and mix it into a concentration of 3mol/L salt solution respectively, mix them fully, and stir until evenly to obtain a mixed salt solution. In terms of CuO, ZnO and _ZrO2 , wherein CuO80wt%, ZnO10wt%, _ZrO210wt %; take sodium hydroxide, ammonia and water, and prepare an alkali solution with an OH ^- concentration of 3mol/L;

(2) Precipitation: Add the alkali solution prepared in step (1) into the mixed salt solution, react at a temperature of 85° C., and the pH value at the titration end point is 6.0 to 8.0;

(3) Aging: Fully stir the catalyst precursor obtained in step (2), and age for 120 minutes at a temperature of 80°C;

(4) Repeatedly washing and centrifuging the precipitate obtained in step (3) and drying at 110° C. for 13 hours;

(5) Calcining the dried product in step (4) at 400° C. for 6 hours to obtain a CuO-ZnO-ZrO ₂ composite catalyst.

The obtained CuO-ZnO-ZrO ₂ composite catalyst can be uniformly mixed with a binder before use, and after being rolled, pressed into tablets, sieved, and then activated; the binder is graphite, and the amount of graphite added is 5 wt%.

The obtained catalyst was heated to 220° C. in a flow of 10% H ₂ /inert gas, then kept at constant temperature, and then reduced for 1 h. The degree of reduction of the catalyst after activation is 78%.

The degree of reduction of CuO in CuO-ZnO- _ZrO2 catalysts can be determined by the following methods: the amount of CuO reduction and the amount of Cu generation detected in XRD.

The activated catalyst is applied to remove trace amounts of CO in hydrocarbons and/or inert gases. The specific method is: at a temperature of 40° C. and a reaction pressure of 0.1 MPa, styrene containing trace amounts of CO is mixed with the catalyst Contact, gas phase space velocity 10h ^-1 , remove CO in the material to make the content ≤ 20ppb.

Claims (13)

1. the catalyst of a low temperature deep removal CO is characterized in that, this catalyst is by CuO, ZnO, ZrO ₂Composite oxides form CuO-ZnO-ZrO ₂Composite catalyst is 100% in total catalyst weight, wherein CuO:50～90wt%; ZnO:5～40wt%; ZrO ₂: 5～40wt%, wherein to have reduction degree be 70～80% to the cupric component, said reduction degree is to represent in metallic copper and metallic copper with the weight ratio of the summation of the Cu oxide of CuO.

2. the Preparation of catalysts method of a low temperature deep removal CO according to claim 1 is characterized in that, this method may further comprise the steps:

(1) preparation of slaine and aqueous slkali: take by weighing a certain amount of mantoquita, zinc salt, zirconates and water, being mixed with concentration respectively is to mix behind 0.2～3mol/L salting liquid, is stirred well to evenly, obtains mixing salt solution, with CuO, ZnO and ZrO ₂Meter, wherein CuO 50～90wt%, ZnO 5～40wt%, ZrO ₂5～40wt%; Take by weighing alkali and water, be mixed with the aqueous slkali that concentration is 0.2～3mol/L;

(2) deposition: mixing salt solution and aqueous slkali that step (1) is made adopt cocurrent process or suitable addition hybrid reaction, obtain deposition and are catalyst precursor;

(3) aging: the catalyst precursor of step (2) gained is fully stirred, under 60～85 ℃ of temperature, aging 30～240min;

(4) with step (3) gained deposition through cyclic washing, centrifugal after in 110 ℃ of drying 12～16h;

(5) with the product after step (4) oven dry in 300～600 ℃ of roastings 6 hours, promptly get CuO-ZnO-ZrO ₂Composite catalyst.

3. the Preparation of catalysts method of low temperature deep removal CO according to claim 2; It is characterized in that; The described mantoquita of step (1) comprises one or more in copper nitrate, copper sulphate, Schweinfurt green or the copper chloride; Described zinc salt comprises one or both in zinc nitrate or the zinc sulfate, and described zirconates comprises one or more in zirconium nitrate, zirconium sulfate, zirconium oxychloride or the acetic acid zirconium; Described alkali comprises one or more in sodium carbonate, sodium acid carbonate, NaOH, ammoniacal liquor or the ammonium carbonate.

4. the Preparation of catalysts method of low temperature deep removal CO according to claim 3 is characterized in that, described mantoquita is a copper nitrate, and described zinc salt is a zinc nitrate, and described zirconates is a zirconium nitrate, and described alkali is ammonium carbonate.

5. the Preparation of catalysts method of low temperature deep removal CO according to claim 2; It is characterized in that; The described cocurrent process of step (2) is: add mixing salt solution and aqueous slkali in the container simultaneously; Under 50～85 ℃ of temperature, react, deposition pH value 6.0～8.0, the mol ratio of mixing salt solution and aqueous slkali addition is 1: 1;

Described along addition for aqueous slkali is added in the salting liquid, under 50～85 ℃ of temperature, react titration end-point pH value 6.0～8.0.

6. the Preparation of catalysts method of low temperature deep removal CO according to claim 2 is characterized in that, the temperature of the described roasting of step (5) is 320～500 ℃.

7. the Preparation of catalysts method of low temperature deep removal CO according to claim 2 is characterized in that, step (5) gained CuO-ZnO-ZrO ₂Can mix with adhesive before composite catalyst uses, through stone roller and after compression molding, screening, to be activated; Described adhesive is the various adhesives that shaping of catalyst can be used, and the addition of adhesive is 0.1～5wt%.

8. the Preparation of catalysts method of low temperature deep removal CO according to claim 7 is characterized in that, described adhesive is a graphite.

9. the activation method of the catalyst of a low temperature deep removal CO as claimed in claim 1 is characterized in that, this method is: with said catalyst at 1～10%H ₂Constant temperature after being warming up to 120～220 ℃ in the/inert gas flow, reduction 1～12h.

10. the activation method of the catalyst of low temperature deep removal CO according to claim 9; It is characterized in that; Preferred 160 ℃ of described reduction temperature; Preferred 3～6h of recovery time, the activated back of described catalyst reduction degree is 70～80%, said reduction degree is to represent in metallic copper and metallic copper with the weight ratio of the summation of the Cu oxide of CuO.

11. the Application of Catalyst of a low temperature deep removal CO as claimed in claim 1; It is characterized in that; With said catalyst applications trace amounts of CO in removing hydrocarbon and/or inert gas, concrete grammar is: in temperature is 0～150 ℃, and reaction pressure is under the condition of 0.1～5MPa; Make the material that contains trace amounts of CO contact liquid phase air speed 0.1～100h with said catalyst ^-1, gas phase air speed 10～100000h ^-1, the CO that removes in the material makes its content≤20ppb.

12. the Application of Catalyst of low temperature deep removal CO according to claim 11 is characterized in that described catalyst is converted into CO with CO ₂, the said material that contains trace amounts of CO comprises alpha-olefin, saturated hydrocarbons, cinnamic gas phase or liquid phase or N ₂, the content of CO is 0.02ppm～1000ppm in the described material that contains trace amounts of CO; When the described material that contains trace amounts of CO was the liquid phase state hydrocarbon, reaction temperature was 0～50 ℃.

13. the Application of Catalyst of low temperature deep removal CO according to claim 11 is characterized in that, the preferred 0.02ppm～100ppm of content of CO in the described material that contains trace amounts of CO.