Copper-cerium bimetallic oxide CeCuO x Preparation method of catalyst and its application in catalytic degradation of polycyclic aromatic hydrocarbons in oil-containing wastewater

Abstract

The present invention discloses a preparation method of a copper-cerium bimetallic oxide CeCuO x and its application in catalytic degradation of polycyclic aromatic hydrocarbons in oil-containing wastewater. The preparation method of the copper-cerium bimetallic oxide CeCuO x catalyst comprises the following steps: (1) Weigh copper phthalocyanine, cerium salt and small molecule carboxylic acid, fully stir and dissolve them in a mixed solvent of water and ethanol, and then evaporate to dryness to form a uniform powder; (2) Place the powder in a muffle furnace and calcine it in an air atmosphere; (3) Place the calcined sample in an inorganic acid for surface activation to obtain the copper-cerium bimetallic oxide CeCuO x catalyst. The copper-cerium bimetallic oxide CeCuO x catalyst prepared by the present invention has high activity in the degradation process of catalytic degradation of polycyclic aromatic hydrocarbons in oil-containing wastewater and has a high removal rate for polycyclic aromatic hydrocarbons.

Description

Technical Field

[0001] The present invention relates to the field of catalytic technology, and in particular to a copper-cerium bimetallic oxide CeCuO x A method for preparing a catalyst and its application in catalytic degradation of polycyclic aromatic hydrocarbons in oily wastewater. Background Art

[0002] Polycyclic aromatic hydrocarbons (PAHs) are a class of persistent organic pollutants that are ubiquitous in the environment. They have strong carcinogenic, teratogenic and mutagenic effects and are the earliest discovered carcinogens with the largest number. PAHs have a conjugated structure of multiple benzene rings and also have strong fluorescence absorption properties, which makes the chemical properties of PAHs very stable and not easily degraded in nature. In addition, PAHs have strong lipophilicity and are easily enriched and concentrated in the lipids of organisms, and have high bioaccumulation. PAHs mainly come from human activities and energy utilization processes, such as petrochemical product production, offshore oil development, and spills during oil transportation.

[0003] At present, the research on PAHs in environmental media in China mainly focuses on the atmosphere, soil, surface sediments and bioaccumulation, and there is little research on PAHs pollution in water bodies. Therefore, it is necessary to provide a new catalyst to degrade PAHs in environmental water bodies. Summary of the invention

[0004] In view of this, the object of the present invention is to provide a copper-cerium bimetallic oxide CeCuO x The invention discloses a method for preparing a catalyst and application thereof in catalytic degradation of polycyclic aromatic hydrocarbons in oily wastewater. The catalyst prepared by the invention has high activity in catalytic degradation of polycyclic aromatic hydrocarbons in oily wastewater.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] The invention discloses a copper-cerium bimetallic oxide CeCuO x The method for preparing the catalyst comprises the following steps:

[0007] (1) copper phthalocyanine, cerium salt and small molecular carboxylic acid are weighed, stirred thoroughly and dissolved in a mixed solvent of water and ethanol, and then evaporated to dryness to form a uniform powder;

[0008] (2) placing the powder in a muffle furnace and calcining in an air atmosphere;

[0009] (3) The calcined sample was placed in an inorganic acid for surface activation to obtain copper-cerium bimetallic oxide CeCuO x catalyst.

[0010] As a preferred technical solution, in the step (1), copper phthalocyanine and cerium salt are weighed according to the molar ratio of Cu / Ce of 0.2 to 2:1.

[0011] As a preferred technical solution, in the step (1), copper phthalocyanine and cerium salt are weighed according to the molar ratio of Cu / Ce of 2:1.

[0012] As a preferred technical solution, in the step (1), the cerium salt is one or more of cerium nitrate, cerium chloride and ammonium cerium nitrate, the small molecule carboxylic acid is one or more of citric acid, malic acid and tartaric acid, and the molar ratio of the small molecule carboxylic acid to the metal ion is 1.8.

[0013] As a preferred technical solution, in the step (2), the calcination temperature is 350°C to 750°C.

[0014] As a preferred technical solution, in the step (2), the calcination temperature is 650°C.

[0015] As a preferred technical solution, in the step (3), the inorganic acid is one of sulfuric acid or hydrochloric acid, and its concentration is 1 to 5 mM.

[0016] The present invention also discloses a copper-cerium bimetallic oxide CeCuO x catalyst prepared by the above preparation method.

[0017] The present invention also discloses an application of a copper-cerium bimetallic oxide CeCuO x catalyst in catalytic degradation of polycyclic aromatic hydrocarbons in oily wastewater.

[0018] As a preferred technical solution, first add the copper-cerium bimetallic oxide CeCuO x catalyst to the wastewater for an adsorption reaction, and then add H2O2 for a reaction of catalytic degradation of polycyclic aromatic hydrocarbons.

[0019] The beneficial effects of the present invention are as follows:

[0020] The present invention selects copper phthalocyanine as the precursor for preparing the CeCuO x catalyst. Because copper phthalocyanine has a benzene ring skeleton support, it can prevent the excessive agglomeration of Cu atoms during high-temperature calcination, and improve the phase dispersion degree of CuO; after calcination, CuO and CeO2 form a CeCuO x solid solution with strong interaction, and the Cu 2+ -O-Ce 4+ bond formed at the interface makes the redox potential of Cu 2+ / Cu + become positive, promoting the regeneration of Cu + during the catalytic oxidation of H2O2; at the same time, the present invention also removes CeCuO through the activation of inorganic acid.x The CuO phase with a weak interaction between the catalyst surface and CeO₂ exposes more active sites and reduces the precipitation of Cu during the reaction. 2+ Therefore, the copper-cerium bimetallic oxide CeCuO x catalyst prepared in the present invention has high activity and a high removal rate for polycyclic aromatic hydrocarbons during the catalytic degradation of polycyclic aromatic hydrocarbons in water. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to make the objectives, technical solutions, and beneficial effects of the present invention clearer, the following drawings are provided for illustration:

[0022] Figure 1 A photograph of the copper-cerium bimetallic oxide CeCuO x catalyst (Cu 50 Ce 50 ) prepared in Example 1.

[0023] Figure 2 The XRD image of the copper-cerium bimetallic oxide CeCuO x catalyst (Cu 50 Ce 50 ) prepared in Example 1.

[0024] Figure 3 The graph showing the change of the removal rate of the pollutant 2-naphthol with time by four copper-cerium bimetallic oxide CeCuO x catalysts prepared in Example 1.

[0025] Figure 4 The graph showing the change of the removal rate of the pollutant 2-naphthol with time by five copper-cerium bimetallic oxide CeCuO x catalysts prepared in Example 3. DETAILED DESCRIPTION OF THE INVENTION

[0026] The present invention will be further described below with reference to the drawings and specific examples, so that those skilled in the art can better understand the present invention and implement it, but the examples given are not intended to limit the present invention.

[0027] Example 1. Preparation of copper-cerium bimetallic oxide CeCuO x catalyst

[0028] (1) Weigh copper phthalocyanine and cerium nitrate according to the molar ratio of Cu / Ce of 0.2 - 2:1, and weigh citric acid according to the molar ratio of 1.8 to metal ions. Stir well and dissolve in a mixed solvent of water and ethanol (volume ratio 1:2), and then evaporate to dryness to form a uniform powder;

[0029] (2) Place the powder in a muffle furnace and heat it in an air atmosphere at 10 °C min-1 The temperature was raised to 650 °C and calcined at 650 °C for 3.0 hours;

[0030] (3) The calcined sample was put into a sulfuric acid solution with a concentration of 0.001 mol / L for surface activation for 1.0 hour to prepare the copper-cerium bimetallic oxide CeCuO x catalyst.

[0031] Example 1 prepared four copper-cerium bimetallic oxide CeCuO x catalysts, namely Cu 17 Ce 83 (Cu / Ce molar ratio is 0.2:1), Cu 33 Ce 67 (Cu / Ce molar ratio is 0.5:1), Cu 50 Ce 50 (Cu / Ce molar ratio is 1:1), Cu 67 Ce 33 (Cu / Ce molar ratio is 2:1).

[0032] The copper-cerium bimetallic oxide CeCuO x catalyst (Cu 50 Ce 50 ) is as Figure 1 shown.

[0033] The XRD image of the copper-cerium bimetallic oxide CeCuO x catalyst (Cu 50 Ce 50 ) prepared in Example 1 is as Figure 2 shown, and diffraction peaks of both CuO and CeO2 phases appear in the CuCeO x catalyst.

[0034] Example 2. Removal effect of copper-cerium bimetallic oxide CeCuO x catalyst with different Cu / Ce molar ratios on the pollutant 2-naphthol

[0035] (1) Weigh 20 mg of the four copper-cerium bimetallic oxide CeCuO x catalysts prepared in Example 1 and place them in conical flasks;

[0036] (2) Add 100 mL of 100 mg / L 2-naphthol to the conical flask, add a magnetic stirrer of type B, and in a constant temperature water bath magnetic stirrer at 65 °C, the stirring rate is 1000 rpm, keep stirring evenly, and start the adsorption reaction;

[0037] (3) After reacting for 30 min, take samples and add 0.4 mL of H2O2 respectively to start the catalytic reaction;

[0038] (4) Determine the reactivity as follows:

[0039] a) At 35 min, 40 min, 45 min, 50 min, 60 min, 90 min, and 120 min during the reaction, use a glass syringe to take samples (about 3 mL) from the reaction solution in the conical flask and filter through a 0.45 μm needle filter.

[0040] b) Pipette 1 mL of the sample into a colorimetric tube, then dilute it to 25 mL with water and let it stand for 10 min.

[0041] c) Use a UV spectrophotometer (UV1000) to measure the concentration of 2-naphthol.

[0042] The four kinds of copper-cerium bimetallic oxides CeCuO prepared in Example 1 x The removal rate of the pollutant 2-naphthol by the catalyst changes with time as Figure 3 shown. The results show that during the degradation of 2-naphthol by catalysts with different Cu / Ce molar ratios, the removal rate of 2-naphthol increases with time, and the removal effect of 2-naphthol increases with the increase of the Cu / Ce molar ratio. The removal rate of 2-naphthol by the catalyst with a Cu / Ce molar ratio of 2:1 reaches 98.8%.

[0043] Example 3. Copper-cerium bimetallic oxides CeCuO prepared at different calcination temperatures x Catalyst

[0044] (1) Weigh copper phthalocyanine and cerium nitrate according to the ratio of Cu / Ce molar ratio of 1:1, and weigh citric acid according to the molar ratio of 1.8 to metal ions. Stir well and dissolve in a mixed solvent of water and ethanol (volume ratio 1:2), and then evaporate to dryness to form a uniform powder.

[0045] (2) Place the powder in a muffle furnace and program the temperature to 350, 450, 550, 650, and 750 °C at a rate of 10 °C / min in an air atmosphere, and calcine at a constant temperature for 3.0 hours. -1 Program the temperature to 350, 450, 550, 650, 750 °C at a rate of 10 °C / min in an air atmosphere, and calcine at a constant temperature for 3.0 hours.

[0046] (3) Put the calcined sample into a sulfuric acid solution with a concentration of 0.001 mol / L for surface activation for 1.0 hour to obtain the copper-cerium bimetallic oxide CeCuO x Catalyst.

[0047] Example 4. The removal effect of copper-cerium bimetallic oxides CeCuO prepared at different calcination temperatures x The removal effect of the catalyst on the pollutant 2-naphthol

[0048] (1) Weigh 20 mg of the five kinds of copper-cerium bimetallic oxides CeCuO prepared in Example 3 respectivelyx The catalyst was placed in a conical flask;

[0049] (2) 100 mL of 100 mg / L 2-naphthol was added to the conical flask, a magnetic stirrer bar of type B was added, and in a constant temperature water bath magnetic stirrer at 65 °C, the stirring rate was 1000 rpm, and uniform stirring was maintained to start the adsorption reaction;

[0050] (3) After reacting for 30 min, samples were taken and 0.4 mL of H2O2 was added respectively to start the catalytic reaction;

[0051] (4) To determine the reaction activity, the steps were as follows:

[0052] a) At 35 min, 40 min, 45 min, 50 min, 60 min, 90 min, and 120 min during the reaction, samples (about 3 mL) were taken from the reaction solution in the conical flask using a glass syringe and filtered through a 0.45 μm needle filter;

[0053] b) 1 mL of the sample was pipetted into a colorimetric tube, then diluted to 25 mL with water and left to stand for 10 min;

[0054] c) The concentration of 2-naphthol was measured using an ultraviolet spectrophotometer (UV1000);

[0055] The five kinds of copper-cerium bimetallic oxides CeCuO prepared in Example 3 x The removal rate of the pollutant 2-naphthol by the catalyst changed with time as Figure 4 shown, and the results showed that the copper-cerium bimetallic oxide CeCuO x catalyst prepared by calcination at 650 °C had the highest removal rate of 2-naphthol.

[0056] The above-described embodiments are only preferred embodiments given to fully illustrate the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or transformations made by those skilled in the art on the basis of the present invention are all within the protection scope of the present invention. The protection scope of the present invention shall be subject to the claims.

Claims

1. A preparation method of a copper-cerium bimetallic oxide CeCuO x catalyst, characterized in that: It includes the following steps: (1) Weigh copper phthalocyanine, cerium salt and small molecule carboxylic acid. After fully stirring, dissolve them in a mixed solvent of water and ethanol, and then evaporate to dryness to form a uniform powder. In the step (1), weigh copper phthalocyanine and cerium salt according to the molar ratio of Cu / Ce being 2:1; (2) Place the powder in a muffle furnace and calcine it in an air atmosphere. In the step (2), the calcination temperature is 650 °C; (3) The calcined sample is placed in an inorganic acid for surface activation to obtain a copper-cerium bimetallic oxide CeCuO x catalyst.

2. The preparation method of the copper-cerium bimetallic oxide CeCuO according to claim 1 x , characterized in that: In the step (1), the cerium salt is one or more of cerium nitrate, cerium chloride and ammonium cerium nitrate, the small molecule carboxylic acid is one or more of citric acid, malic acid and tartaric acid, and the molar ratio of the small molecule carboxylic acid to metal ions is 1.

8.

3. The preparation method of the copper-cerium bimetallic oxide CeCuO according to claim 1 x is characterized in that: In the step (3), the inorganic acid is one of sulfuric acid or hydrochloric acid, and its concentration is 1 - 5 mM.

4. The copper-cerium bimetallic oxide CeCuO prepared by the preparation method according to any one of claims 1 to 3 x catalyst.

5. Application of the copper-cerium bimetallic oxide CeCuO described in claim 4 x in the catalytic degradation of polycyclic aromatic hydrocarbons in oily wastewater.

6. The application according to claim 5, wherein: First, add the copper-cerium bimetallic oxide CeCuO x catalyst to the wastewater for an adsorption reaction, and then add H2O2 for the catalytic degradation reaction of polycyclic aromatic hydrocarbons.

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