GB2615839A

GB2615839A - Preparation and use of shaped catalyst for normal temperature catalytic oxidation of volatile organic compound (VOC) of ethyl acetate

Info

Publication number: GB2615839A
Application number: GB2205794.7A
Authority: GB
Inventors: Li Quan; Ding Hui; Zhao Dan
Original assignee: Tianjin Tianke Tongchuang Tech Co Ltd
Current assignee: Tianjin Tianke Tongchuang Tech Co Ltd
Priority date: 2022-02-18
Filing date: 2022-04-21
Publication date: 2023-08-23
Also published as: CN114471661A; GB202205794D0; CN114471661B

Abstract

A method for the preparation of a nitrogen-doped activated carbon supported nickel shaped (Ni/NAC) catalyst for the normal temperature oxidation of a volatile organic compound (VOC) of ethyl acetate comprising an initial pre-treatment of activated carbon (AC) with hydrochloric acid to remove dust, washing with deionized water, washing with sodium hydroxide with ultrasonic irradiation, followed by a drying step with further ultrasonic radiation. Once the AC is pre-treated, active sites are created by adding it to water along with NH4Cl, C6H12O6, CH4N2O and Ni(NO3)2 ∙ 6H2O. This solution is subjected to ultrasonic irradiation and stirred while evaporating the water. The resulting product is washed before calcination in a muffle furnace. The sample is then annealed under N2 and cooled to room temperature to obtain the Ni/NAC catalyst. Also disclosed is the use of a shaped Ni/NAC catalyst, such as Ni/NAC-900, for the normal temperature catalytic oxidation of a VOC of ethyl acetate.

Description

PREPARATION AND USE OF SHAPED CATALYST FOR NORMAL TEMPERATURE CATALYTIC OXIDATION OF VOLATILE ORGANIC COMPOUND (VOC) OF

ETHYL ACETATE

TECHNICAL FIELD

100011 The present disclosure belongs to the technical field of catalysts, and particularly relates to preparation and use of a shaped catalyst for normal temperature catalytic oxidation of a volatile organic compound (VOC) of ethyl acetate.

BACKGROUND ART

100021 In recent years, with the development of urbanization and industrialization, lots of volatile organic compounds (VOCs) have been emitted to the environment. Some components in the emitted VOCs are carcinogenic, teratogenetic, and mutagenic, and some components are precursors for forming haze or photochemical smog, leading to detrimental effects on the atmospheric environment and human health.

100031 At present, the detrimental effects of VOCs on the ecological environment and human health have attracted extensive attention from various countries in the world. With increasing emphasis on ecological civilization construction in China, the abatement of VOCs has become one of environmental problems brought into focus in today's society and received consideration concern from the related national department. Accordingly, increasingly stringent emission regulations have been promulgated. In the face of the severe situation of atmospheric pollution and the strict requirements of emission standards, the prevention and control at the source and the treatment at the end for VOCs become increasingly urgent, and effective methods for the abatement of VOCs seem to be particularly important.

100041 According to the definition of the World Health Organization (WHO), VOCs are a class of organic compounds with a boiling point in a range of 50°C to 260°C under normal pressure (10E325 KPa). The anthropogenic emission sources of VOCs are mainly from industrial processes (43%), automobile exhaust (28%), daily life (15%) and agriculture (14%). Industrial emissions of VOCs are widely involved in the fields such as petroleum refining, solvent production, fossil fuel use, and coal combustion. The emissions of VOCs by coal firing account for a large proportion in industrial sources, even up to 37%. The emissions of VOCs may come from a variety of outdoor and indoor sources. The outdoor sources include but are not limited to production with organic chemical raw materials, synthetic resins, food processing, paint drying, transportation, petroleum refining, automobile manufacturing, leather manufacturing, textile printing and dyeing, production of electronic parts and components, solvents, and cleaning products. The indoor sources of pollution include household products, office supplies, printers, heat exchanger systems, insulating materials, stoves, and pipeline leakage.

[0005] Currently, the most promising technique for the abatement of VOCs is catalytic oxidation Due to the economic and technical advantages of the catalytic oxidation, people have been working on the research of high-performance catalysts for catalytic oxidation, hoping to reduce the temperature and energy consumption required for the oxidation of VOCs. However, due to a huge quantity of organic molecules and various problems such as a wide range of sources and complex mixing of VOCs, poor formability of catalysts, high reaction temperatures, and easy deactivation of catalysts at high temperatures, the design of catalytic materials has always been a challenging task.

[0006] Scientific researchers have done a lot of work on the development and optimization of powder catalysts for VOCs. Unfortunately, powder catalysts cannot be directly applied to actual industrialization for reasons such as difficult separation, easy clogging, inconvenient transportation and storage, and high pressure drop. Compared with powder catalysts, monolithic catalysts have better mass transfer performance, structural stability and good clogging resistance. The monolithic catalysts typically have a large surface area and a plurality of parallel channels to reduce the pressure drop in the catalyst bed and are also highly adjustable in shape and size, and thus has advantages over powder catalysts in practical use.

[0007] In current research on monolithic catalysts, ceramics (mainly composed of cordierite and clay) or metals (stainless steel, metal alloys, metal foams, metal meshes, etc.) are usually chosen as monolithic support materials, which have also received increasing attention for superior mechanical strength and heat transfer capability of their honeycomb structure. A widely used loading method in industrial applications is generally carried out in two steps, namely firstly preparing an active powder and making the active powder into a paint or slurry, and then loading the paint or slurry on a monolithic support by coating, dip coating, vacuum coating, etc. Such a method often results in agglomeration, migration and even separation of active species on the surface of the support during actual catalytic reaction, leading to deactivation of the catalyst and significant degradation in catalytic performance. Therefore, shaped catalysts generally exhibit poor stability.

[0008] Among VOCs, ethyl acetate is one of the most widely used and stable esters, and also is an organic raw material and a commonly used solvent. Ethyl acetate can cause serious environmental pollution and harm human health. Compared with traditional thermal incineration, catalytic oxidation can eliminate ethyl acetate contamination at high efficiency and low energy consumption.

SUMMARY

100091 The technical problem to be solved in the present disclosure is to provide preparation and use of a shaped catalyst for normal temperature catalytic oxidation of a VOC of ethyl acetate, which may have the advantages of high efficiency, low consumption, safety, significant reduction of metal load, saving of preparation cost, and ease of use on a large scale.

100101 To achieve the above objective, the present disclosure adopts the following technical solutions. Preparation of a shaped catalyst for normal temperature catalytic oxidation of a VOC of ethyl acetate includes the following steps: 100111 step 1, pretreatment of activated carbon (AC): washing columnar AC with a hydrochloric acid solution to remove dust, drying the AC after washing with deionized water for neutralization, subjecting the washed AC to ultrasonic irradiation in a sodium hydroxide solution, followed by shaking in a shaker, taking out and subjecting the AC to ultrasonic irradiation again, drying the AC after washing with deionized water for neutralization, cooling the AC to room temperature, putting the treated AC in a sample bag and placing the sample bag in a dryer for later use; and 100121 step 2, creation of active sites: putting NH4C1, C61-11206, C1-14N20 and Ni(NO3)226020 into a beaker, adding deionized water to the beaker, uniformly dispersing under ultrasonic irradiation, adding the pretreated AC to the beaker with continuous ultrasonic irradiation, followed by magnetic stirring at a certain temperature for evaporation of water, washing a resulting product with deionized water three times and then slowly drying the washed product in a blast air oven, transferring the sample to a porcelain crucible and placing the porcelain crucible in a muffle furnace for calcining by heating in air atmosphere, after naturally cooling to room temperature, transferring the sample to a corundum boat, placing the corundum boat in a tubular furnace and heating to a certain temperature in N2 atmosphere for annealing, and naturally cooling to room temperature, thereby obtaining an Ni/NAC catalyst.

100131 Preferably, step I specifically includes: using a commercially available columnar AC having a diameter of 1.5 mm and a height of 3-6 mm, washing the columnar AC with a 5% (by mass) hydrochloric acid solution to remove dust before use, drying the AC in the blast air oven at 100°C for 5 h after washing with deionized water for neutralization, subjecting 25 g of the washed AC to ultrasonic irradiation in 100 mL of 10 mol.L-1 sodium hydroxide solution for 30 min, followed by shaking in the shaker at 60°C for 11 h, taking out and subjecting the AC to ultrasonic irradiation again for 30 min, drying the AC in the blast air oven at 100°C for 5 h after washing with deionized water for neutralization, cooling the AC to room temperature, putting the treated AC in the sample bag and placing the sample bag in the dryer for later use.

100141 Preferably, step 2 specifically includes: putting 10 g of NH4C1, 2.5 g of C61-11206, 15 g of CELN70 and 4.13 g of Ni(NO3)2-6H20 into a 600 mL beaker, adding deionized water to the beaker to 200 mL, uniformly dispersing under ultrasonic irradiation for 20 min, adding 10 g of the pretreated AC to the beaker with continuous ultrasonic irradiation for 60 mm, followed by magnetic stirring at 60°C for 12 h for evaporation of water, washing the product with deionized water three times and then slowly drying the washed product in the blast air oven at 60°C for 12 h, transferring the sample to a 50 mL porcelain crucible and placing the porcelain crucible in the muffle furnace for calcining for 3 h by heating to 350°C at a rate of St *min-1 in air atmosphere, after naturally cooling to room temperature, transferring the sample to the corundum boat, placing the corundum boat in the tubular furnace and heating to a certain temperature at a rate of min1 in N2 atmosphere for annealing for 3 h, and naturally cooling to room temperature, thereby obtaining the Ni/NAC catalyst.

[0015] Further provided is use of a shaped catalyst for normal temperature catalytic oxidation of a VOC of ethyl acetate, where a shaped catalyst Ni/MAC is used in normal temperature catalytic oxidation of a VOC of ethyl acetate.

[0016] Preferably, when the shaped catalyst is Ni/NAC-900, the Ni/MAC-900 catalyst is used under conditions of a relative humidity (RH) of 18%, an initial concentration Cm of ethyl acetate of 540.mr3, and a gas hourly space velocity (GHSV) of 25000h-'.

[0017] Preferably, when the shaped catalyst is Ni/NAC-900, the Ni/NAC-900 catalyst is capable of keeping an ethyl acetate degradation rate of more than or equal to 90% in 56.5 h under a normal temperature ambient condition, and reacts under the following conditions: Tr=25t, Cin=540 mg-m-3, Tr=25°C, GHSV-5000 h-1, and RH-18%.

[0018] Preferably, when the shaped catalyst is Ni/NAC-900, the Ni/NAC-900 catalyst is capable of completely removing ethyl acetate for a time merely reduced by 20 min after 3 cycles under the normal temperature ambient condition, and reacts under the following conditions: Tr=25t, Cin=540 mgm3, GHSV=20000 h-1, and RH=18%.

[0019] With the above technical solutions, the key of the normal temperature catalytic oxidation technique is the design of a high-activity catalyst. The characteristics such as geometry and electron structure of catalytic active sites are regulated to reduce the reaction activation energy and increase the reaction rate, whereby oxidative decomposition of ethyl acetate under conditions of normal temperature and normal pressure can be achieved. According to the present disclosure, a nitrogen-doped activated carbon (NAC) supported Ni shaped catalyst (Ni/MAC) is synthesized by loading atomic-scale active sites on cheap and easily available preformed AC as a support according to a chelation-pyrolysis strategy. The atomic efficiency and the quantity of sites at the interface are maximized to provide excellent catalytic activity and structural stability. A simple one-pot impregnation method is used to synthesize a nitrogen-doped AC supported Ni (Ni/NAC) catalyst.

[0020] The present disclosure combines a heterogeneous preformed catalytic support with single-atom catalysis to achieve normal temperature catalytic oxidation of ethyl acetate. Breaking through the conventional thinking of needing energy input in oxidation of VOCs, effective degradation of VOCs is achieved under the conditions of normal temperature and normal pressure without high temperature, high pressure, electric discharge and ultraviolet light. Normal temperature catalysis can significantly save energy consumed in the process and improve the safety of abatement of VOCs This technique is a leapfrogging improvement over the traditional catalytic incineration technique and opens up an efficient, low-consumption and safe new way for degradation of VOCs.

BRIEF DESCRIPTION OF THE DRAWINGS

100211 The present disclosure will be described below with reference to the accompanying drawings and examples, from which the advantages and implementations of the present disclosure will become obvious. The contents shown in the accompanying drawings are merely meant to explain the present disclosure rather than limit the present disclosure in all senses. 100221 FIG. 1 shows the effects of different relative humidities on the performance of a Ni/NAC catalyst for normal temperature catalytic oxidation of ethyl acetate according to the present disclosure.

100231 FIG. 2 shows the effects of different initial concentrations of ethyl acetate on the performance of the Ni/NAC catalyst for normal temperature catalytic oxidation of ethyl acetate according to the present disclosure.

[0024] FIG. 3 shows the effects of different GHSVs on the performance of the Ni/NAC catalyst for normal temperature catalytic oxidation of ethyl acetate according to the present disclosure. [0025] FIG. 4 shows long-term stability of the Ni/NAC catalyst according to the present disclosure.

[0026] FIG. 5 shows cyclic stability of the Ni/NAC catalyst according to the present disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] The present disclosure will be further described with reference to examples.

100281 Preparation of a shaped catalyst for normal temperature catalytic oxidation of a VOC of ethyl acetate includes the following steps: [0029] Step I, pretreatment of activated carbon (AC): a commercially available columnar AC having a diameter of 1.5 mm and a height of 3-6 mm was washed with a 5% (by mass) hydrochloric acid solution to remove dust. After washing with deionized water for neutralization, the AC was dried in a blast air oven at 100°C for 5 h. Subsequently, 25 g of the washed AC was subjected to ultrasonic irradiation in 100 mL of 10 mol-L-I sodium hydroxide solution for 30 min, and then shaken in a shaker at 60°C for 11 h. The AC was taken out and subjected to ultrasonic irradiation again for 30 min. After washing with deionized water for neutralization, the AC was dried in the blast air oven at 100°C for 5 h, cooled to room temperature, put into a sample bag, and placed in a dryer for later use.

[0030] Step 2, creation of active sites: 10 g of NH4C1, 2.5 g of C6E11206, 15 g of CH4N20 and 4.13 g of Ni(N01)-ii6Hi0 were and put into a 600 mL beaker, added with deionized water to 200 mL, and then uniformly dispersed under ultrasonic irradiation for 20 min. Next, 10 g of the pretreated AC was added to the beaker and continuously subjected to ultrasonic irradiation for 60 min. Subsequently, magnetic stirring was performed at 60°C for 12 h for evaporation of water. A resulting product was washed with deionized water three times and then slowly dried in the blast air oven at 60°C for 12 h. The sample was transferred to a 50 mL porcelain crucible and placed in a muffle furnace for calcining for 3 h by heating to 350°C at a rate of 5°Cimin-1 in air atmosphere. After naturally cooling to room temperature, the sample was transferred to a corundum boat, placed in a tubular furnace and heated to a certain temperature at a rate of 5 t imind in N2 atmosphere for annealing for 3 h, and naturally cooled to room temperature, thereby obtaining a Ni/MAC catalyst.

[0031] Further provided is use of a shaped catalyst for normal temperature catalytic oxidation of a VOC of ethyl acetate, where a shaped catalyst Ni/MAC is used in normal temperature catalytic oxidation of a VOC of ethyl acetate.

[0032] The Ni/MAC catalyst was a Ni/NAC-900 (calcined at 900°C) catalyst.

[0033] Effects of relative humidities: 100341 The present disclosure studied the performance of the Ni/NAC catalyst for normal temperature catalytic oxidation of ethyl acetate with relative humidities (RH) of 5%, 10%, 18%, 25%, 30%, and 42%. Reaction occurred under the following conditions: Tr=25t, Cin=540 mg*mr1, and GHSV=20000 WI, and results were shown in FIG. I. An appropriate humidity condition was beneficial to catalytic oxidation of ethyl acetate. The optimum humidity condition was RH=18%. When RH was above 20%, the catalytic performance declined sharply. This was owing to inhibition of adsorption of ethyl acetate molecules as active sites were occupied by excessive water molecules, which further impeded the catalytic oxidation reaction thereof [0035] Effects of initial concentrations of ethyl acetate [0036] Under actual industrial conditions, VOCs emitted from different industries vary greatly in exhaust concentration. Therefore, it is of great reference significance for actual industrial use of the catalyst to know the performance of the Ni/NAC-900 catalyst under different concentrations of ethyl acetate. In the present disclosure, a series of initial concentrations (Cin=540, 1000, 1300, 2000, and 2800 mg.m') of ethyl acetate were designed, and the performance of the Ni/NAC-900 catalyst for catalytic oxidation degradation of ethyl acetate under different initial concentrations was investigated, with reaction conditions of Tr=25t, RH=18%, and GHSV=20000 h-1. Evaluation results were shown in FIG. 2. With increasing initial concentration, the complete degradation time of ethyl acetate was gradually shortened. This was owing to insufficient contact between reactant molecules and active oxygen under high concentrations, which reduced the oxidation efficiency. With reference to potential emission concentrations of ethyl acetate during actual industrial processes, Cin=540 mg*m-3 was selected for subsequent evaluation in the present disclosure.

100371 Effects of gaseous hourly space velocity (GHSV): 100381 GHSV was used in the present disclosure, representing the amount of a gas handled by the catalyst per unit volume within unit time, in units of WI. A large GHSV meant a great amount of exhaust gas passing through the catalyst in unit time, i.e., a short residence time of the exhaust gas on the catalyst and a shallow reaction depth. Conversely, a small GHSV meant a long reaction time. A decrease in GHSV was beneficial to the improvement of the catalytic effect. However, a low GHSV meant more catalyst needed under the condition of the same handling capacity, which impaired the economical efficiency of the abatement process. In general, a higher allowed GEISV indicates higher activity and greater handling capability of the catalyst. The selection of the GHSV in industrial use is usually determined according to various aspects such as expected investment, catalyst activity, properties of raw materials, and product requirements. The present disclosure investigated the handling capability of the Ni/NAC-900 catalyst for ethyl acetate under different GHSVs (GHSV=5000, 10000, b000, 20000, and 25000 h-1). Reaction occurred under the following conditions: Tr=25 °C, Cin=540 mg*m-3, and RH=18%, and results were shown in FIG. 3. With increasing GHSV, the complete removal time of ethyl acetate was shortened. This was owing to insufficient contact between reactant molecules and the catalyst under high GHSVs.

100391 Stability of the Ni/NAC-900 catalyst: 100401 The long-term stability of the Ni/NAC-900 catalyst was investigated, and proper measures were taken to recover the activity of the catalyst after the effects of the catalyst started to decline. The cyclic stability of the catalyst was investigated, which was of great significance for actual engineering applications.

100411 1) Long-term stability 100421 Under the process conditions of Tr=25t, Cin=540 mgm3, Tr=25t, GHSV=5000 h-', and RI-118%, the performance of the Ni/NAC-900 catalyst for normal temperature catalytic oxidation of ethyl acetate was tested, and compared with that of AC with no supported metal, with results shown in FIG. 4. Under such process conditions, the AC with no supported metal was saturated after 24.5 h adsorption of ethyl acetate, and subsequently could not continuously adsorb ethyl acetate. The Ni/NAC-900 catalyst could function in completely removing ethyl acetate for 50.5 h, which was twice or higher the adsorption effect of pure AC. To a certain extent, this showed that the Ni/NAC-900 catalyst was capable of degrading the adsorbed ethyl acetate into other small-molecule products in addition to adsorbing ethyl acetate. Accordingly, the complete removal time of ethyl acetate could be significantly prolonged after adsorption saturation of AC. Also, the results showed that the Ni/NAC-900 catalyst exhibited good long-term stability and could keep an ethyl acetate degradation rate of more than or equal to 90% in 56.5 h under the normal temperature ambient condition.

[0043] (2) Cyclic stability 100441 The deactivation of the catalyst was attributed to the change in the nature of active sites or the active sites of the catalytic reaction being covered with carbon deposits formed in the reaction process. The carbon deposits could be removed by vaporization with H2, 02, 03 or N2 relatively easily. The temperature required for vaporization of the deposits varied with the types of gases, the structure and reactive activity of the deposits, and the activity of the catalyst.

[0045] The catalyst was regenerated by heat treatment: the Ni/NAC-900 catalyst that exhibited declined performance was placed in the tubular furnace and heated to 500,0 at a rate of 5°C -min' for pyrolysis for 2 h in N2 atmosphere. After naturally cooling to room temperature, the catalyst was used in the normal temperature catalytic oxidation reaction of ethyl acetate again under the conditions of Tr=25 T2, Cin=540 mgm3, GHSV=20000 11-', and RH=18%. Cyclic regeneration results were as shown in FIG. 5. After 3 cycles, the completely removal time of ethyl acetate by the Ni/NAC-900 catalyst was merely reduced by 20 min, indicating that the Ni/NAC-900 catalyst had excellent cyclic stability. In addition, this also demonstrated that the deactivation process of the Ni/NAC-900 catalyst was reversible. After reaction, the deactivated catalyst could be effectively regenerated by pyrolysis at 500C for 2 h in the tubular furnace in nitrogen atmosphere. To a certain extent, the results also indicated that the deactivation of the Ni/NAC-900 catalyst was caused by a by-product from incomplete oxidation of ethyl acetate depositing on the surface of the catalyst and covering the catalytic active sites.

100461 The Ni/NAC catalyst in the present disclosure exhibited the performance for the normal temperature catalytic oxidation reaction of ethyl acetate under ambient conditions. The structural and physicochemical characteristics of the active sites of the catalyst were regulated by controlling the preparation conditions, the pyrolysis procedure, the components and proportions of the catalyst, and the catalyst having the optimum performance was obtained. Furthermore, the optimum humidity condition for reaction was obtained by exploring the optimal process parameters of the Ni/NAC-900 catalyst for the normal temperature catalytic oxidation reaction of ethyl acetate, and the performance indexes for the Ni/NAC-900 catalyst under different process conditions were obtained, providing reference for the actual industrial use of the catalyst. Besides, the long-term stability and the recyclability of the Ni/NAC-900 catalyst were studied. 100471 Thus, the key of the normal temperature catalytic oxidation technique is the design of a high-activity catalyst. The characteristics such as geometry and electron structure of catalytic active sites are regulated to reduce the reaction activation energy and increase the reaction rate, whereby oxidative decomposition of ethyl acetate under conditions of normal temperature and normal pressure can be achieved.

100481 The examples of the present disclosure are described above in detail, which are merely preferred examples of the present disclosure and cannot be construed as limiting the scope of implementation of the present disclosure. Any equivalent modifications, improvements, and the like made within the scope of the present disclosure should fall within the protection scope of the present disclosure.

Claims

WHAT IS CLAIMED IS: I. Preparation of a shaped catalyst for normal temperature catalytic oxidation of a volatile organic compound (VOC) of ethyl acetate, comprising the following steps: step 1, pretreatment of activated carbon (AC): washing columnar AC with a hydrochloric acid solution to remove dust, drying the AC after washing with deionized water for neutralization, subjecting the washed AC to ultrasonic irradiation in a sodium hydroxide solution, followed by shaking in a shaker, taking out and subjecting the AC to ultrasonic irradiation again, drying the AC after washing with deionized water for neutralization, cooling the AC to room temperature, putting the treated AC in a sample bag and placing the sample bag in a dryer for later use; and step 2, creation of active sites: putting NH4C1, C6H1206, CH4N20 and Ni(NO3)2-61-120 into a beaker, adding deionized water to the beaker, uniformly dispersing under ultrasonic irradiation, adding the pretreated AC to the beaker with continuous ultrasonic irradiation, followed by magnetic stirring at a certain temperature for evaporation of water, washing a resulting product with deionized water three times and then slowly drying the washed product in a blast air oven, transferring the sample to a porcelain crucible and placing the porcelain crucible in a muffle furnace for calcining by heating in air atmosphere, after naturally cooling to room temperature, transferring the sample to a corundum boat, placing the corundum boat in a tubular furnace and heating to a certain temperature in N2 atmosphere for annealing, and naturally cooling to room temperature, thereby obtaining an Ni/NAC catalyst.
2. The preparation of a shaped catalyst for normal temperature catalytic oxidation of a VOC of ethyl acetate according to claim 1, wherein step 1 specifically comprises: using a commercially available columnar AC having a diameter of 1.5 mm and a height of 3-6 mm, washing the columnar AC with a 5% (by mass) hydrochloric acid solution to remove dust before use, drying the AC in the blast air oven at 100°C for 5 h after washing with deionized water for neutralization, subjecting 25 g of the washed AC to ultrasonic irradiation in 100 mL of 10 mo1.1_,-1 sodium hydroxide solution for 30 min, followed by shaking in the shaker at 60°C for 11 h, taking out and subjecting the AC to ultrasonic irradiation again for 30 min, drying the AC in the blast air oven at 100°C for 5 h after washing with deionized water for neutralization, cooling the AC to room temperature, putting the treated AC in the sample bag arid placing the sample bag in the dryer for later use.
3. The preparation of a shaped catalyst for normal temperature catalytic oxidation of a VOC of ethyl acetate according to claim 2, wherein step 2 specifically comprises: putting 10 g of NH4CI, 2.5 g of GT11206, 15 g of CI-14NA) and 4.13 g of Ni(NO3)2-6H20 into a 600 mL beaker, adding deionized water to the beaker to 200 mL, uniformly dispersing under ultrasonic irradiation for 20 min, adding 10 g of the pretreated AC to the beaker with continuous ultrasonic irradiation for 60 min, followed by magnetic stirring at 60°C for 12 h for evaporation of water, washing the product with deionized water three times and then slowly drying the washed product in the blast air oven at 60°C for 12 h, transferring the sample to a 50 mL porcelain crucible and placing the porcelain crucible in the muffle furnace for calcining for 3 h by heating to 350°C at a rate of 5r *min' in air atmosphere, after naturally cooling to room temperature, transferring the sample to the corundum boat, placing the corundum boat in the tubular furnace and heating to a certain temperature at a rate of 5C min' in N2 atmosphere for annealing for 3 h, and naturally cooling to room temperature, thereby obtaining the Ni/NAC catalyst.
4 Use of a shaped catalyst for normal temperature catalytic oxidation of a VOC of ethyl acetate, wherein a shaped catalyst Ni/NAC is used in normal temperature catalytic oxidation of a VOC of ethyl acetate The use of a shaped catalyst for normal temperature catalytic oxidation of a VOC of ethyl acetate according to claim 4, wherein when the shaped catalyst is Ni/NAC-900, the Ni/NAC-900 catalyst is used under conditions of a relative humidity (RH) of 18%, an initial concentration Cin of ethyl acetate of 540.m-3, and a gas hourly space velocity (GHSV) of 2500011-1.6. The use of a shaped catalyst for normal temperature catalytic oxidation of a VOC of ethyl acetate according to claim 4, wherein when the shaped catalyst is Ni/NAC-900, the Ni/NAC-900 catalyst is capable of keeping an ethyl acetate degradation rate of more than or equal to 90% in 56.5 h under a normal temperature ambient condition, and reacts under the following conditions: Tr=25°C, Cin=540 mg.m-3, Tr=25°C, GHSV=5000 h-1, and RH=18%.7. The use of a shaped catalyst for normal temperature catalytic oxidation of a VOC of ethyl acetate according to claim 4, wherein when the shaped catalyst is Ni/NAC-900, the Ni/NAC-900 catalyst is capable of completely removing ethyl acetate for a time merely reduced by 20 min after 3 cycles under the normal temperature ambient condition, and reacts under the following conditions: Tr=25t, Cin=540 mg-m-3, GHSV=20000 h-1, and RH=18%.WHAT IS CLAIMED IS: 1. Preparation of a shaped catalyst for normal temperature (25°C) catalytic oxidation of a volatile organic compound (VOC) of ethyl acetate, comprising the following steps: step 1, pretreatment of activated carbon (AC): washing columnar AC with a hydrochloric acid solution to remove dust, drying the AC after washing with deionized water for neutralization, subjecting the washed AC to ultrasonic irradiation in a sodium hydroxide solution, followed by shaking in a shaker, taking out and subjecting the AC to ultrasonic irradiation again, drying the AC after washing with deionized water for neutralization, cooling the AC to room temperature, putting the treated AC in a sample bag and placing the sample bag in a dryer for later use; and step 2, creation of active sites: putting N1-140, glucose (C6F11206), urea (Cl-14N70) and Ni(NO3)2.6H20 into a beaker, adding deionized water to the beaker, uniformly dispersing under ultrasonic irradiation, adding the pretreated AC to the beaker with CO continuous ultrasonic irradiation, followed by magnetic stirring at 60°C for evaporation of water, washing a resulting product with deionized water three times CID and then slowly drying the washed product in a blast air oven, transferring the sample to a porcelain crucible and placing the porcelain crucible in a muffle furnace for calcining by heating to 350°C in air atmosphere, after naturally cooling to room C\J temperature, transferring the sample to a corundum boat, placing the corundum boat in a tubular furnace and heating to 900°C in N4 atmosphere for annealing, and naturally cooling to room temperature, thereby obtaining an Ni/NAC catalyst.2. The preparation of a shaped catalyst for normal temperature catalytic oxidation of a VOC of ethyl acetate according to claim 1, wherein step 1 specifically comprises: using a commercially available columnar AC having a diameter of 1.5 mm and a height of 3-6 mm, washing the columnar AC with a 5% (by mass) hydrochloric acid solution to remove dust before use, drying the AC in the blast air oven at 100°C for 5 h after washing with deionized water for neutralization, subjecting 25 g of the washed AC to ultrasonic irradiation in 100 mL of 10 mol*L-I sodium hydroxide solution for 30 mm, followed by shaking in the shaker at 60°C for 11 h, taking out and subjecting the AC to ultrasonic irradiation again for 30 mm, drying the AC in the blast air oven at 100°C for 5 h after washing with deionized water for neutralization, cooling the AC to room temperature, putting the treated AC in the sample bag and placing the sample bag in the dryer for later use.3. The preparation of a shaped catalyst for normal temperature catalytic oxidation of a VOC of ethyl acetate according to claim 2, wherein step 2 specifically comprises: putting 10 g of NH4C1, 2.5 g of C6H1206, 15 g of CH4N20 and 4.13 g of Ni(N103)/.61-1/0 into a 600 mL beaker, adding deionized water to the beaker to 200 mL, uniformly dispersing under ultrasonic irradiation for 20 min, adding 10 g of the pretreated AC to the beaker with continuous ultrasonic irradiation for 60 min, followed by magnetic stirring at 60°C for 12 h for evaporation of water, washing the product with deionizal water three times and then slowly drying the washed product in the blast air oven at 60°C for 12 h, transferring the sample to a 50 mL porcelain crucible and placing the porcelain crucible in the muffle furnace for calcining for 3 h by heating to 350°C at a rate of 5°C. min-1 in air atmosphere, after naturally cooling to room temperature, transferring the sample to the corundum boat, placing the CO corundum boat in the tubular furnace and heating to 900°C at a rate of 5°C*min-I in Nn atmosphere for annealing for 3 h, and naturally cooling to room temperature, CD thereby obtaining the Ni/NAC catalyst 4. A method of normal temperature catalytic oxidation of a VOC of ethyl acetate, C\I comprising the steps of: preparing a shaped catalyst by the preparation of any one of claims 1 to 3, and using the shaped catalyst Ni/NAC in normal temperature catalytic oxidation of a VOC of ethyl acetate.
5. The method according to claim 4, wherein the Ni/NAC catalyst is used under conditions of a relative humidity (RH) of 18%, an initial concentration Cu of ethyl acetate of 540 m-3, and a gas hourly space velocity (GHSV) of 25000 h-1.
6. The method according to claim 4, wherein the Ni/NAC catalyst is capable of keeping an ethyl acetate degradation rate of more than or equal to 90% in 56.5 h under a normal temperature ambient condition, and reacts under the following conditions: Tr=25°C, Cin=540 rng*rn-3, Tr=25°C, GHSV=5000 h-1, and RH=18%.
7. The method according to claim 4, wherein the Ni/NAC catalyst is capable of completely removing ethyl acetate for a time merely reduced by 20 min after 3 cycles under the normal temperature ambient condition, and reacts under the following conditions: Tr=25°C, Cin=540 ma.m-3, GHSV=2000011-1, and RH=18%.CO C\ICD C\1