Benzene catalytic oxidation decomposition method

Abstract

The invention discloses a benzene catalytic oxidation decomposition method which is characterized by comprising the following steps: 1, adsorbing benzene molecules and oxygen molecules on the surface of a biomass activated carbon / CeO2 / Ag phase material, and generating a carboxylate form through a series of reactions; and 2, carrying out catalytic decomposition on the generated carboxylate morphological structure to generate carbon dioxide and water. Benzene in indoor air can be decomposed more efficiently, and harm of benzene to the human body and the home environment is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of treatment of polluted gas decomposition, and particularly relates to a method for catalytic oxidation decomposition of benzene. Background Art

[0002] Benzene, with the chemical formula C6H6, formerly known as qun, yan, xun, zhouzhi, etc., is the simplest aromatic hydrocarbon. It is insoluble in water, soluble in organic solvents and volatile, and can itself be used as an organic solvent. Benzene is commonly used as a raw material for dyes and plastics. Benzene and benzene compounds are often hidden in paints, coatings and additives of various coatings, and also exist in various adhesives and waterproof materials. Therefore, benzene is one of the main indoor gaseous pollutants. After new houses are decorated, it is easy to volatilize into the air and cause harm to the human body.

[0003] When the human body inhales benzene, it will seriously harm the respiratory system, central nervous system and inhibit the bone marrow hematopoiesis function. Therefore, it is necessary to carry out efficient and rapid purification treatment on it. Compared with the commonly used adsorption trapping and ventilation methods, the catalytic oxidation method has greater application prospects. It can not only convert benzene into harmless carbon dioxide and water vapor to achieve complete purification of benzene, but also can be recycled and purified without additional energy consumption, which helps to reduce the energy consumption and carbon emissions during the operation of buildings. A preparation method of a cobalt ferrite catalyst for benzene catalytic oxidation disclosed in CN109382111A, an anti-high temperature aging lanthanum-doped spherical manganese oxide catalyst and its preparation disclosed in CN115193432A, and a CuMnAl hydrotalcite catalyst and its preparation method and application disclosed in CN115055184A are all technologies for removing benzene by catalytic oxidation. However, the existing benzene catalytic oxidation method has low efficiency, and the catalytic oxidation ability gradually decreases with the progress of the reaction process, making it difficult to achieve rapid and long-term purification of indoor air.

[0004] Therefore, how to provide a method for catalytic oxidation decomposition of benzene that can more efficiently achieve the catalytic oxidation treatment of benzene in indoor air has become a problem to be considered and solved by those skilled in the art. Summary of the Invention

[0005] Aiming at the deficiencies of the above-mentioned prior art, the technical problem to be solved by the present invention is: how to provide a method for catalytic oxidation decomposition of benzene that can more efficiently achieve the catalytic oxidation treatment of benzene in indoor air to reduce the harm of benzene to the human body and the home environment.

[0006] To solve the above technical problem, the present invention adopts the following technical solutions:

[0007] A method for catalytic oxidation decomposition of benzene, characterized by comprising the following steps:

[0008] In the first step, benzene molecules and oxygen molecules are adsorbed on the surface of biomass activated carbon / CeO2 / Ag phase material to generate carboxylate form through a series of reactions; the reaction process includes the following reaction formula:

[0009] C6H6+ * O → ···CH-CO-CH-CH-CH-CH··· + * H;

[0010] ···CH-CO-CH-CH-CH-CH··· + * O → ···C2H2-CO-CO-C2H2··· + * H;

[0011] ···C2H2-CO-CO-C2H2···+ * O →···CH-CO-O-CO-CH··· + * CH-CH * ;

[0012] ···CH-CO-O-CO-CH··· + * O + 2 * H → COOH-CH=CH-COOH (carboxylate form);

[0013] In the second step, the generated carboxylate morphology is catalytically decomposed to generate carbon dioxide and water. The reaction formula can be characterized as follows:

[0014] COOH-CH=CH-COOH + 2 * O → 2H2O + 2CO2 + * C;

[0015] * CH-CH * + * O → H2O + 2 * C; * C + 2 * O → CO2.

[0016] Thus, the present invention uses biomass activated carbon embedded with CeO2 and Ag as the catalytic oxidation decomposition material of benzene, and the above reaction process can quickly and efficiently realize the catalytic oxidation decomposition of benzene molecules. In this process, firstly, the biomass activated carbon substrate has a high specific surface area (> 300 m 2 / g), which can provide a large number of available sites for the adsorption of benzene and oxygen molecules; secondly, CeO2 and Ag embedded in the surface of biomass activated carbon can be used to provide lattice oxygen and active electrons, respectively. The synergistic cooperation of the two can greatly reduce the energy barrier of the catalytic oxidation process of benzene.

[0017] Furthermore, in the present invention, a benzene catalytic oxidation decomposition material whose main effective components are biomass activated carbon / CeO2 / Ag phase is used to achieve catalytic oxidation decomposition treatment of benzene.

[0018] In the above-mentioned benzene catalytic oxidation treatment material, biomass activated carbon serves as a matrix for loading effective ingredients CeO2 and Ag and capturing and adsorbing benzene and oxygen molecules, and is the base bed for the catalytic reaction. The specific reaction process principle is as follows.

[0019] (a) The role of CeO2. In the above basic process of benzene catalytic oxidation, both the initial reactant C6H6 and the intermediate reactants ···CH-CO-CH-CH-CH-CH···, etc., need to react with active oxygen atoms. * O combination reaction, active oxygen atoms can generally be generated by the decomposition of oxygen or directly provided by metal oxides. CeO2 is an active metal oxide, and the strength of the metal bond formed between Ce-O is much lower than the covalent bond in the oxygen molecule. Therefore, the energy barrier for the Ce-O metal bond to provide active oxygen atoms is much lower than the energy barrier for the oxygen covalent bond to provide active oxygen atoms. Then, relying on the lattice oxygen of CeO2 to provide active oxygen atoms greatly reduces the difficulty of the continuous reaction of benzene catalytic oxidation. Furthermore, due to the lack of lattice oxygen in CeO2, a potential well region will be formed there, attracting free oxygen molecules to approach and combine with the surrounding cerium atoms to form supplementary lattice oxygen, thereby weakening the strength of the covalent bond in the oxygen molecule, and the other oxygen atom in the oxygen molecule will enter a quasi-stable state due to the weakening of the covalent bond, and the energy barrier for its combination with C6H6 / ···CH-CO-CH-CH-CH-CH···, etc. is greatly reduced, thereby easily forming active oxygen atoms to promote the continuous reaction of benzene catalytic oxidation.

[0020] (b) The role of Ag. In the above basic process of benzene catalytic oxidation, the continuous reaction between benzene molecules and active oxygen atoms involves the rapid transfer of electrons, such as in "C6H6 + * O → ···CH-CO-CH-CH-CH-CH··· + *H" process, electrons are transferred from active oxygen atoms to newly generated active hydrogen atoms. It should be noted that due to the large energy barrier and other reasons, electrons will not be transferred directly from one atom to another, but need to use catalytic active atoms as bridges to reduce the energy barrier. Considering that in the above-mentioned catalytic oxidation process of benzene, the initial reactants and intermediates such as C6H6 / ···CH-CO-CH-CH-CH-CH··· are all adsorbed on the surface of biomass activated carbon / CeO2 / Ag phase, Ag can directly dissociate the outermost valence electrons as active electrons to provide them to the required intermediate structure. At the same time, due to the strong chemical activity of Ag, the above-mentioned process of dissociating the outermost valence electrons as active electrons can be completed without external energy input. Furthermore, the process in which the above-mentioned oxygen molecules combine with the cerium atoms that have lost lattice oxygen to generate supplementary lattice oxygen also requires the participation of surface electrons to promote the formation of Ce-O metal bonds. The active electrons generated by the direct dissociation of the outermost valence electrons by Ag can be directly transferred to this place through the delocalized π bonds on the surface of biomass activated carbon, accelerating the formation of supplementary lattice oxygen and indirectly promoting the continuous reaction of benzene catalytic oxidation.

[0021] Therefore, the present invention can rapidly catalytically oxidize and decompose trace amounts of benzene in the room into carbon dioxide and water, thereby reducing the harm of benzene to the human body; it can improve the efficiency / rate of catalytic oxidation decomposition of benzene, and achieve rapid purification of indoor air. The applicant has verified that the present invention can increase the efficiency of catalytic oxidation of benzene from 65% to 85%+; and reduce the average energy barrier of the catalytic oxidation process of benzene from 0.7 eV to 0.2 eV.

[0022] Furthermore, the benzene catalytic oxidation decomposition material used in the present invention includes the following phase components in the following mass proportions: 0.01-0.08 parts of biomass activated carbon phase, 0.01-0.10 parts of CeO2 phase, 0.01-0.05 parts of Ag phase, and 0.77-0.97 parts of biomass activated carbon / CeO2 / Ag phase.

[0023] Further better mass ratios are: 0.05 parts of biomass activated carbon phase, 0.05 parts of CeO2 phase, 0.05 parts of Ag phase, and 0.85 parts of biomass activated carbon / CeO2 / Ag phase.

[0024] Among the above-mentioned benzene catalytic oxidation decomposition materials, the biomass activated carbon / CeO2 / Ag phase is the main site of the benzene catalytic oxidation reaction and therefore accounts for a relatively large proportion. The biomass activated carbon phase, CeO2 phase and Ag phase are common reaction products and can also be used to provide reaction sites and assist in enhancing the benzene catalytic oxidation process. Moreover, the components of each phase can have a certain dynamic conversion and complementary effect, thereby better ensuring the durability of the treatment effect.

[0025] Furthermore, the benzene catalytic oxidation decomposition material is prepared by the following steps:

[0026] Step 1: First obtain biomass activated carbon as a substrate;

[0027] Step 2: Dissolve the above-obtained biomass activated carbon in 1 L of deionized water, add 0.25 mol of cerium chloride heptahydrate (CeCl3·7H2O) and 0.25 mol of silver nitrate (AgNO3), and then add 300 ml of a sodium hydroxide solution (NaOH) with a molar concentration of 9 mol / L, stir the mixed solution and perform hydrothermal treatment (as a preferred stirring and hydrothermal treatment process, place it in a magnetic stirrer and stir it continuously at 200 r / min at 50°C for 2 h, and then place the obtained mixed suspension in a sealed aluminum reactor and react at 200°C for 15 h); filter the suspension after hydrothermal treatment (preferably by filtering through a cellulose filter membrane), and wash the obtained filter residue (preferably, the filter residue washing process is to rinse it with deionized water 5 times and dry it in a drying oven for 50 ℃ and dried to evaporate all moisture to obtain agglomerates) and then ground to 300 mesh powder; then calcined to obtain the benzene catalytic oxidation decomposition material (preferably, the calcination process is to place the 300 mesh powder in a muffle furnace and calcine at 800 ℃ for 2 h under argon (Ar) protection, and then cool to room temperature with natural ventilation, wherein the heating rate from room temperature to 800 ℃ before calcination is 20 ℃ / min, to obtain a biomass carbon-based supported cerium-silver composite catalyst).

[0028] In the above preparation process, cerium chloride and sodium hydroxide attached to the surface of biomass activated carbon react in the hydrothermal process to generate light yellow precipitated cerium hydroxide (Ce(OH)4), and the reaction equation is CeCl3 + NaOH + O2 + H2O → Ce(OH)4+ NaCl; cerium hydroxide and silver nitrate attached to the surface of biomass activated carbon are decomposed into cerium oxide (CeO2) and elemental silver (Ag) during high-temperature calcination, and the reaction equations are Ce(OH)4 → CeO2 + H2O, AgNO3 → Ag + NO2 +O2, respectively; the CeO2 and Ag generated above will be embedded in the biomass activated carbon during the high-temperature calcination process to form a carbon-based supported cerium-silver composite catalyst, and the reaction equation is C n + CeO2 + Ag →···C···CeO2···C···Ag···C···.

[0029] Therefore, the above reaction process can quickly and efficiently produce a benzene catalytic oxidation decomposition material with the main effective component of biomass activated carbon / CeO2 / Ag phase accounting for more than 50%, ensuring the efficient catalytic oxidation decomposition effect of benzene after adsorption. At the same time, the other phase components generated are evenly mixed and doped together, which can help improve the effect of the decomposition reaction and better ensure the durability of the catalytic treatment effect of benzene.

[0030] Furthermore, the biomass carbon-based substrate was prepared by the following method: 100 g of bamboo-based biomass powder was weighed, dissolved in 1 L of deionized water, and then placed in a sealed aluminum reactor to react at 200 °C for 15 h; the suspension after hydrothermal treatment was filtered through a cellulose filter membrane, the resulting filter residue was rinsed with deionized water for 5 times, dried in a drying oven at 50 °C to evaporate all moisture, and then agglomerates were obtained, which were then ground into a 200-mesh powder state; the above-mentioned bamboo-based biomass 200-mesh powder was placed in a muffle furnace and calcined at 800 °C for 2 h under argon (Ar) protection, and then naturally cooled to room temperature by ventilation, wherein the heating rate from room temperature to 800 °C was 20 °C / min; the above-mentioned bamboo-based biomass 200-mesh powder after the first calcination was ground again to 300 mesh, and then placed in a muffle furnace and calcined at 500 °C for 8 h in an air atmosphere, and then naturally cooled to room temperature by ventilation, wherein the heating rate from room temperature to 500 °C was 20 °C / min. The heating rate of ℃ was 10 ℃ / min, and biomass activated carbon was obtained.

[0031] In this way, the biomass carbon-based substrate uses bamboo-based biomass powder after hydrothermal treatment, washing, filtering and evaporation to complete the initial removal of non-carbonized components, and then completes carbonization through two grinding and calcination treatments, so that the prepared pure bamboo-based biomass activated carbon can have higher adsorption efficiency, low preparation cost and improved adsorption effect. The initial bamboo-based biomass powder is converted into biomass activated carbon after hydrothermal treatment and high-temperature calcination, and the reaction equation is: C (amorphous / inactive) → C (activated carbon).

[0032] Therefore, the present invention has the following characteristics: 1. It can capture and quickly catalyze and oxidize trace amounts of benzene in the room, decompose it into carbon dioxide and water, and reduce the harm of benzene to the human body; 2. It improves the efficiency / rate of catalytic oxidation decomposition of benzene, and realizes rapid purification of indoor air; 3. It improves the recycling efficiency of catalytic oxidation of benzene, and realizes long-term purification of indoor air.

[0033] In summary, the present invention can more efficiently achieve the decomposition and treatment of benzene in indoor air, thereby reducing the harm of benzene to the human body and the home environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 The present invention is a schematic diagram of the principle process of the catalytic oxidation decomposition material for benzene.

[0035] Figure 2 It is a schematic diagram comparing the decomposition efficiency of the benzene catalytic oxidation decomposition material of the present invention and other types of benzene catalytic oxidation decomposition materials.

[0036] Figure 3 It is a schematic diagram comparing the average energy barriers of the processes of the benzene catalytic oxidation decomposition material of the present invention and other types of benzene catalytic oxidation decomposition materials. DETAILED DESCRIPTION

[0037] The present invention is further described in detail below in conjunction with specific implementation modes.

[0038] Implementation method: A method for catalytic oxidation and decomposition of benzene, characterized in that it comprises the following steps:

[0039] In the first step, benzene molecules and oxygen molecules are adsorbed on the surface of biomass activated carbon / CeO2 / Ag phase material to generate carboxylate form through a series of reactions; the reaction process includes the following reaction formula:

[0040] C6H6+ * O → ···CH-CO-CH-CH-CH-CH··· + * H;

[0041] ···CH-CO-CH-CH-CH-CH··· + * O → ···C2H2-CO-CO-C2H2··· + * H;

[0042] ···C2H2-CO-CO-C2H2···+ * O →···CH-CO-O-CO-CH··· + * CH-CH * ;

[0043] ···CH-CO-O-CO-CH··· + * O + 2 * H → COOH-CH=CH-COOH (carboxylate form);

[0044] In the second step, the generated carboxylate morphology is catalytically decomposed to generate carbon dioxide and water. The reaction formula can be characterized as follows:

[0045] COOH-CH=CH-COOH + 2 * O → 2H2O + 2CO2 + * C;

[0046] * CH-CH * + * O → H2O + 2 * C; * C + 2 * O → CO2.

[0047] Thus, the present invention uses biomass activated carbon embedded with CeO2 and Ag as the catalytic oxidation decomposition material of benzene, and the above reaction process can quickly and efficiently realize the catalytic oxidation decomposition of benzene molecules. In this process, firstly, the biomass activated carbon substrate has a high specific surface area (> 300 m 2 / g), which can provide a large number of available sites for the adsorption of benzene and oxygen molecules; secondly, CeO2 and Ag embedded in the surface of biomass activated carbon can be used to provide lattice oxygen and active electrons, respectively. The synergistic cooperation of the two can greatly reduce the energy barrier of the catalytic oxidation process of benzene.

[0048] Specifically, in the present invention, a benzene catalytic oxidation decomposition material whose main effective components are biomass activated carbon / CeO2 / Ag phase is used to achieve catalytic oxidation decomposition treatment of benzene.

[0049] In the above-mentioned benzene catalytic oxidation treatment material, biomass activated carbon serves as a matrix for loading effective ingredients CeO2 and Ag and capturing and adsorbing benzene and oxygen molecules, and is the base bed for the catalytic reaction. The specific reaction process principle is as follows.

[0050] (a) The role of CeO2. In the above basic process of benzene catalytic oxidation, both the initial reactant C6H6 and the intermediate reactants ···CH-CO-CH-CH-CH-CH···, etc., need to react with active oxygen atoms. * O combination reaction, active oxygen atoms can generally be generated by the decomposition of oxygen or directly provided by metal oxides. CeO2 is an active metal oxide, and the strength of the metal bond formed between Ce-O is much lower than the covalent bond in the oxygen molecule. Therefore, the energy barrier for the Ce-O metal bond to provide active oxygen atoms is much lower than the energy barrier for the oxygen covalent bond to provide active oxygen atoms. Then, relying on the lattice oxygen of CeO2 to provide active oxygen atoms greatly reduces the difficulty of the continuous reaction of benzene catalytic oxidation. Furthermore, due to the lack of lattice oxygen in CeO2, a potential well region will be formed there, attracting free oxygen molecules to approach and combine with the surrounding cerium atoms to form supplementary lattice oxygen, thereby weakening the strength of the covalent bond in the oxygen molecule, and the other oxygen atom in the oxygen molecule will enter a quasi-stable state due to the weakening of the covalent bond, and the energy barrier for its combination with C6H6 / ···CH-CO-CH-CH-CH-CH···, etc. is greatly reduced, thereby easily forming active oxygen atoms to promote the continuous reaction of benzene catalytic oxidation.

[0051] (b) The role of Ag. In the above basic process of benzene catalytic oxidation, the continuous reaction between benzene molecules and active oxygen atoms involves the rapid transfer of electrons, such as in "C6H6 + * O → ···CH-CO-CH-CH-CH-CH··· + *H" process, electrons are transferred from active oxygen atoms to newly generated active hydrogen atoms. It should be noted that due to the large energy barrier and other reasons, electrons will not be transferred directly from one atom to another, but need to use catalytic active atoms as bridges to reduce the energy barrier. Considering that in the above-mentioned catalytic oxidation process of benzene, the initial reactants and intermediates such as C6H6 / ···CH-CO-CH-CH-CH-CH··· are all adsorbed on the surface of biomass activated carbon / CeO2 / Ag phase, Ag can directly dissociate the outermost valence electrons as active electrons to provide them to the required intermediate structure. At the same time, due to the strong chemical activity of Ag, the above-mentioned process of dissociating the outermost valence electrons as active electrons can be completed without external energy input. Furthermore, the process in which the above-mentioned oxygen molecules combine with the cerium atoms that have lost lattice oxygen to generate supplementary lattice oxygen also requires the participation of surface electrons to promote the formation of Ce-O metal bonds. The active electrons generated by the direct dissociation of the outermost valence electrons by Ag can be directly transferred to this place through the delocalized π bonds on the surface of biomass activated carbon, accelerating the formation of supplementary lattice oxygen and indirectly promoting the continuous reaction of benzene catalytic oxidation.

[0052] Therefore, the present invention can rapidly catalytically oxidize and decompose trace amounts of benzene in the room into carbon dioxide and water, thereby reducing the harm of benzene to the human body; it can improve the efficiency / rate of catalytic oxidation decomposition of benzene, and achieve rapid purification of indoor air. The applicant has verified that the present invention can increase the efficiency of catalytic oxidation of benzene from 65% to 85%+; and reduce the average energy barrier of the catalytic oxidation process of benzene from 0.7 eV to 0.2 eV.

[0053] During implementation, the benzene catalytic oxidation decomposition material used in the present invention includes the following phase components in the following mass proportions: 0.01-0.08 parts of biomass activated carbon phase, 0.01-0.10 parts of CeO2 phase, 0.01-0.05 parts of Ag phase, and 0.77-0.97 parts of biomass activated carbon / CeO2 / Ag phase. A further preferred mass proportion is: 0.05 parts of biomass activated carbon phase, 0.05 parts of CeO2 phase, 0.05 parts of Ag phase, and 0.85 parts of biomass activated carbon / CeO2 / Ag phase.

[0054] Among the above-mentioned benzene catalytic oxidation decomposition materials, the biomass activated carbon / CeO2 / Ag phase is the main site of the benzene catalytic oxidation reaction and therefore accounts for a relatively large proportion. The biomass activated carbon phase and CeO2 phase / Ag phase are common reaction products and can also be used to provide reaction sites and assist in enhancing the benzene catalytic oxidation process. Moreover, the components of each phase can have a certain dynamic conversion and complementary effect, thereby better ensuring the durability of the treatment effect.

[0055] During implementation, the benzene catalytic oxidation decomposition material is prepared by the following steps:

[0056] Step 1: First obtain biomass activated carbon as a substrate;

[0057] Step 2: Dissolve the above-obtained biomass activated carbon in 1 L of deionized water, add 0.25 mol of cerium chloride heptahydrate (CeCl3·7H2O) and 0.25 mol of silver nitrate (AgNO3), and then add 300 ml of sodium hydroxide solution (NaOH) with a molar concentration of 9 mol / L, stir the mixed solution and perform hydrothermal treatment (wherein the stirring and hydrothermal treatment process is to place it in a magnetic stirrer and stir it continuously at 200 r / min at 50 ° C for 2 h, and then place the obtained mixed suspension in a sealed aluminum reactor and react at 200 ° C for 15 h); filter the suspension after hydrothermal treatment (filtered through a cellulose filter membrane during implementation), and wash the obtained filter residue (the specific filter residue washing process is to rinse it with deionized water 5 times and dry it in a drying oven for 50 ℃ and dried to evaporate all moisture to obtain agglomerates) and then ground to 300 mesh powder; then calcined to obtain the benzene catalytic oxidation decomposition material (the specific calcination process is to place the above 300 mesh powder in a muffle furnace and calcine at 800 ℃ for 2 h under argon (Ar) protection, and then cool to room temperature by natural ventilation, wherein the heating rate from room temperature to 800 ℃ before calcination is 20 ℃ / min, to obtain a biomass carbon-based supported cerium-silver composite catalyst).

[0058] In the above preparation process, cerium chloride and sodium hydroxide attached to the surface of biomass activated carbon react in the hydrothermal process to generate light yellow precipitated cerium hydroxide (Ce(OH)4), and the reaction equation is CeCl3 + NaOH + O2 + H2O → Ce(OH)4+ NaCl; cerium hydroxide and silver nitrate attached to the surface of biomass activated carbon are decomposed into cerium oxide (CeO2) and elemental silver (Ag) during high-temperature calcination, and the reaction equations are Ce(OH)4 → CeO2 + H2O, AgNO3 → Ag + NO2 +O2, respectively; the CeO2 and Ag generated above will be embedded in the biomass activated carbon during the high-temperature calcination process to form a carbon-based supported cerium-silver composite catalyst, and the reaction equation is C n + CeO2 + Ag →···C···CeO2···C···Ag···C···.

[0059] Therefore, the above reaction process can quickly and efficiently produce a benzene catalytic oxidation decomposition material with the main effective component of biomass activated carbon / CeO2 / Ag phase accounting for more than 50%, ensuring the efficient catalytic oxidation decomposition effect of benzene after adsorption. At the same time, the other phase components generated are evenly mixed and doped together, which can help improve the effect of the decomposition reaction and better ensure the durability of the catalytic treatment effect of benzene.

[0060] During implementation, the biomass carbon-based substrate was prepared by the following method: 100 g of bamboo-based biomass powder was weighed, dissolved in 1 L of deionized water, and then placed in a sealed aluminum reactor to react at 200 ° C for 15 h; the suspension after hydrothermal treatment was filtered through a cellulose filter membrane, the resulting filter residue was rinsed with deionized water for 5 times, dried in a drying oven at 50 ° C to evaporate all moisture, and then agglomerates were obtained, which were then ground into a 200-mesh powder state; the above-mentioned bamboo-based biomass 200-mesh powder was placed in a muffle furnace and calcined at 800 ° C for 2 h under argon (Ar) protection, and then naturally ventilated to room temperature, wherein the heating rate from room temperature to 800 ° C was 20 ° C / min; the bamboo-based biomass 200-mesh powder after the above-mentioned one-time calcination was ground again to 300 mesh, and then placed in a muffle furnace and calcined at 500 ° C for 8 h in an air atmosphere, and then naturally ventilated to room temperature, wherein the heating rate from room temperature to 500 ° C was 20 ° C / min. The heating rate of ℃ was 10 ℃ / min, and biomass activated carbon was obtained.

[0061] In this way, the biomass carbon-based substrate uses bamboo-based biomass powder after hydrothermal treatment, washing, filtering and evaporation to complete the initial removal of non-carbonized components, and then completes carbonization through two grinding and calcination treatments, so that the prepared pure bamboo-based biomass activated carbon can have higher adsorption efficiency, low preparation cost and improved adsorption effect. The initial bamboo-based biomass powder is converted into biomass activated carbon after hydrothermal treatment and high-temperature calcination, and the reaction equation is: C (amorphous / inactive) → C (activated carbon).

[0062] Therefore, the present invention has the following characteristics: 1. It can capture and quickly catalyze and oxidize trace amounts of benzene in the room, decompose it into carbon dioxide and water, and reduce the harm of benzene to the human body; 2. It improves the efficiency / rate of catalytic oxidation decomposition of benzene, and realizes rapid purification of indoor air; 3. It improves the recycling efficiency of catalytic oxidation of benzene, and realizes long-term purification of indoor air.

[0063] In order to better verify the effect of the present invention, the applicant conducted a comparative test, using the benzene catalytic oxidation decomposition material obtained in the above specific embodiment as the experimental group, and other benzene catalytic oxidation decomposition materials as the comparative group to conduct a comparative test to detect the performance of the benzene catalytic conversion efficiency and the benzene catalytic conversion energy barrier. The results are shown in Figure 2 and Figure 3 .

[0064] for Figure 2, under the environmental conditions of 75 ℃ / 1 bar / 50% relative humidity, a 25 ppm benzene catalytic conversion efficiency comparison experiment was carried out with manganese oxide mixture (MnOx), manganese oxide mixture loaded with cobalt (Co), manganese oxide mixture loaded with copper (Cu) and manganese oxide mixture loaded with cobalt / copper as control groups. From the experimental results, it can be seen that the catalytic conversion rate of benzene by manganese oxide mixture or manganese oxide mixture loaded with metal is lower than that of biomass activated carbon loaded with cerium dioxide / silver (CeO2 / Ag), especially the catalytic conversion rate of benzene by biomass activated carbon loaded with cerium dioxide / silver is much higher than that of manganese oxide mixture, indicating that the catalytic conversion capacity of benzene is greatly enhanced by the simultaneous loading of cerium dioxide / silver on the surface of biomass activated carbon.

[0065] for Figure 3 , under the environmental conditions of 75 ℃ / 1 bar / 50% relative humidity, a 20 ppm benzene catalytic conversion energy barrier comparison experiment was carried out with manganese oxide mixture (MnOx), manganese oxide mixture loaded with cobalt (Co), manganese oxide mixture loaded with copper (Cu) and manganese oxide mixture loaded with cobalt / copper as control groups. From the experimental results, it can be seen that the catalytic conversion energy barrier of benzene by manganese oxide mixture or manganese oxide mixture loaded with metal is higher than that of biomass activated carbon loaded with cerium dioxide / silver (CeO2 / Ag), especially the catalytic conversion energy barrier of benzene by biomass activated carbon loaded with cerium dioxide / silver is much lower than that of manganese oxide mixture, and the catalytic conversion rate is greatly enhanced when cerium dioxide / silver is loaded on the surface of biomass activated carbon to catalyze the conversion of benzene.

Claims

1. A method for catalytic oxidation and decomposition of benzene, characterized in that: The following steps are involved: In the first step, benzene molecules and oxygen molecules are adsorbed on the surface of biomass activated carbon / CeO2 / Ag phase material to generate carboxylate form through a series of reactions; The reaction process includes the following reaction formula: C6H6 + * O → ···CH-CO-CH-CH-CH-CH··· + * H; ···CH-CO-CH-CH-CH-CH··· + * O → ···C2H2-CO-CO-C2H2··· + * H; ···C2H2-CO-CO-C2H2···+ * O →···CH-CO-O-CO-CH··· + * CH-CH * ; ···CH-CO-O-CO-CH··· + * Oh + 2 * H → COOH-CH=CH-COOH; In the second step, the generated carboxylate morphology is catalytically decomposed to generate carbon dioxide and water. The reaction formula can be characterized as follows: COOH-CH=CH-COOH + 2 * O → 2H2O + 2CO2 + * C; * CH-CH * + * O → H2O + 2 * C; * C + 2 * O → CO2。 2. The method for catalytic oxidation and decomposition of benzene according to claim 1, characterized in that: In this method, a benzene catalytic oxidation decomposition material whose main effective component is biomass activated carbon / CeO2 / Ag phase is used to achieve catalytic oxidation decomposition treatment of benzene.

3. The method for catalytic oxidation and decomposition of benzene as claimed in claim 2, characterized in that: The benzene catalytic oxidation decomposition material used in the present invention comprises the following phase components in the following mass proportions: 0.01-0.08 parts of biomass activated carbon phase, 0.01-0.10 parts of CeO2 phase, 0.01-0.05 parts of Ag phase, and 0.77-0.97 parts of biomass activated carbon / CeO2 / Ag phase.

4. The method for catalytic oxidation and decomposition of benzene as claimed in claim 3, characterized in that: The benzene catalytic oxidation decomposition material used in the present invention includes the following phase components in the following mass proportions: 0.05 parts of biomass activated carbon phase, 0.05 parts of CeO2 phase, 0.05 parts of Ag phase, and 0.85 parts of biomass activated carbon / CeO2 / Ag phase.

5. The method for catalytic oxidation and decomposition of benzene as claimed in claim 3, characterized in that: The benzene catalytic oxidation decomposition material is prepared by the following steps: Step 1: First obtain biomass activated carbon as a substrate; Step 2: Dissolve the biomass activated carbon obtained above in 1 L of deionized water, add 0.25 mol of cerium chloride heptahydrate and 0.25 mol of silver nitrate, and then add 300 ml of a sodium hydroxide solution with a molar concentration of 9 mol / L, stir the mixed solution and perform hydrothermal treatment; filter the suspension after hydrothermal treatment, wash the obtained filter residue and grind it into a 300 mesh powder; then calcine to obtain the benzene catalytic oxidation decomposition material.

6. The method for catalytic oxidation and decomposition of benzene according to claim 5, characterized in that: In step 2, the stirring and hydrothermal treatment process is to place the mixture in a magnetic stirrer at 200 r / min and continuously stir and mix at 50 °C for 2 h, and then place the obtained mixed suspension in a sealed aluminum reactor and react at 200 °C for 15 h.

7. The method for catalytic oxidation and decomposition of benzene according to claim 5, characterized in that: In step 2, the suspension after the hydrothermal treatment is filtered through a cellulose filter membrane.

8. The method for catalytic oxidation and decomposition of benzene according to claim 5, characterized in that: In step 2, the filter residue is washed by rinsing with deionized water for 5 times and drying in a drying oven at 50° C. to evaporate all moisture, thereby obtaining agglomerates.

9. The method for catalytic oxidation and decomposition of benzene according to claim 5, characterized in that: In step 2, the calcination process is to place the above-mentioned 300 mesh powder in a muffle furnace and calcine it at 800 ° C for 2 h under argon protection, and then cool it to room temperature by natural ventilation, wherein the heating rate from room temperature to 800 ° C before calcination is 20 ° C / min, to obtain a biomass carbon-based supported cerium-silver composite catalyst.

10. The method for catalytic oxidation and decomposition of benzene according to claim 5, characterized in that: In step 1, the biomass carbon-based substrate is prepared by the following method: weigh 100 g of bamboo-based biomass powder, dissolve it in 1 L of deionized water, and place it in a sealed aluminum reactor to react at 200 ° C for 15 h; filter the suspension after hydrothermal treatment through a cellulose filter membrane, rinse the resulting filter residue with deionized water for 5 times, dry it in a drying oven at 50 ° C to evaporate all moisture, and then obtain agglomerates, which are then ground into 200 mesh powder; place the above-mentioned bamboo-based biomass 200 mesh powder in a muffle furnace and calcine it at 800 ° C for 2 h under argon protection, and then cool it to room temperature by natural ventilation, wherein the heating rate from room temperature to 800 ° C is 20 ° C / min; grind the bamboo-based biomass 200 mesh powder after the above-mentioned one-time calcination again to 300 mesh, and then place it in a muffle furnace and calcine it at 500 ° C for 8 h in an air atmosphere, and then cool it to room temperature by natural ventilation, wherein the heating rate from room temperature to 500 ° C is 20 ° C / min. The heating rate of ℃ was 10 ℃ / min, and biomass activated carbon was obtained.

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