CN111151243A

CN111151243A - Ruthenium-based catalyst, preparation method and application thereof

Info

Publication number: CN111151243A
Application number: CN201811325034.2A
Authority: CN
Inventors: 王胜; 王树东; 吕丽荣; 汪明哲; 李德意
Original assignee: Dalian Institute of Chemical Physics of CAS
Current assignee: Dalian Institute of Chemical Physics of CAS
Priority date: 2018-11-08
Filing date: 2018-11-08
Publication date: 2020-05-15

Abstract

Disclosed is a ruthenium-based catalyst including a carrier and an active component; the active component comprises an active metal element; the active metal element is Ru; the carrier is TiO₂Said TiO being₂The crystal form of (A) is a mixed crystal form of rutile and at least one of anatase and brookite. The ruthenium-based catalyst has the advantages of low cost, high catalytic activity and strong catalytic stability, and can be used for catalytic combustion of different kinds of VOCs.

Description

Ruthenium-based catalyst, preparation method and application thereof

Technical Field

The application relates to a ruthenium-based VOCs purification catalyst and a preparation method thereof, belonging to the field of catalysts and energy environment.

Background

VOCs are organic compounds with boiling points of 50-260 ℃ and saturated vapor pressure of more than 133.322Pa at room temperature. According to different functional groups of VOCs, the VOCs are divided into benzene, alcohol, ketone, phenol, aldehyde, ether, lipid, acid, alkane, alkene, amine and halogenated hydrocarbon 12. The pollution of VOCs to the environment seriously harms and threatens human health seriously, the problem has attracted general attention, the purification treatment of VOCs is urgent, but the catalytic activity of the same catalyst to different types of VOCs is greatly different due to the difference of different types of VOCs functional groups.

The substances with the largest industrial emissions are the triphenyl compounds (benzene, toluene, xylene) and the halogenated hydrocarbons, which are also highly toxic substances, and many volatile halogenated hydrocarbons are considered to have "triple effects" (carcinogenic, teratogenic, mutagenic) or suspected "triple effects". Therefore, the preparation of the catalyst which has higher catalytic activity to halogenated hydrocarbon and benzene and has certain significance to poisoning resistance.

Disclosure of Invention

According to one aspect of the application, a ruthenium-based catalyst is provided, which has the advantages of low cost, high catalytic activity and strong catalytic stability, and can be used for catalytic combustion of different kinds of VOCs.

The noble metal catalyst has the advantages of low ignition temperature, complete combustion, few byproducts and the like, but the noble metal platinum palladium is higher in price, and the ruthenium is lower in cost relatively. Noble ruthenium metal can react Cl/Br on the surface with HCl/HBr and Cl₂/Br₂The form is removed from the surface, thus having high catalytic activity on halogenated hydrocarbons and a certain poisoning resistance. Ru and rutile titanium oxide can form Ru-O-Ti bonds, and the Ru and rutile titanium oxide have strong interaction with a metal carrier, so that the Ru is favorably dispersed on the surface of the carrier. And anatase in the rutile anatase mixed phase titanium oxide can be used as a diluent to separate ruthenium and rutile, so that the dispersibility of ruthenium is further improved.

The ruthenium-based catalyst is characterized in that,

comprises a carrier and an active component;

the active component comprises an active metal element;

the active metal element is Ru;

the carrier is TiO₂Said TiO being₂The crystal form of (A) is a mixed crystal form of rutile and at least one of anatase and brookite.

The mass percentage of the active component in the ruthenium-based catalyst is 0.01-10%;

the weight percentage of the active component is calculated by the weight percentage of the active metal element.

Optionally, the upper limit of the active component by weight of the ruthenium-based catalyst is selected from 0.05%, 0.2%, 0.5%, 1%, 1.5%, 2%, 5%, 8%, or 10%; the lower limit is selected from 0.01%, 0.05%, 0.2%, 0.5%, 1%, 1.5%, 2%, 5% or 8%.

Optionally, the active component further comprises an element M;

the element M is at least one selected from Pd, Pt, Mn, Co, Ni, Cu and Ce;

the weight ratio of M to Ru is 0: 1-20: 1.

optionally, characterized in that the rutile phase is present in the support in an amount greater than 30% by weight.

Optionally, the upper limit of the weight content of the rutile in the support is selected from 35%, 40%, 50%, 55%, 60%, 65%, 70%, 80%, 85% or 95%; the lower limit is selected from 30%, 35%, 40%, 50%, 55%, 60%, 65%, 70%, 80%, 85% or 95%.

Optionally, the rutile is present in the support in an amount of 50% to 70% by weight.

Alternatively, the TiO₂The crystal form is a mixed crystal form of anatase, rutile and brookite.

As one embodiment, the application provides ruthenium-based VOCs purification catalysts, which are noble metal supported catalysts with the structural form of Ru_xN_1-x/TiO_2-m-nM is the baking temperature and n is the baking time. N is one or the combination of more of Pd, Pt, Mn, Co, Ni, Cu and Ce; the weight ratio of N to Ru is 0: 1-20: 1; the total weight of the active components Ru and N accounts for 0.01-10% of the weight of the catalyst; pd, Pt, Mn, Co, Ni, Cu and Ce are combined in any proportion. Support TiO₂The crystal form is a mixed crystal form of anatase, rutile and brookite, and the weight content of the rutile phase is higher than 30%, preferably 50% -70%.

According to another aspect of the present application, there is provided a method for preparing the ruthenium-based catalyst, which is simple to operate and suitable for industrial production.

The preparation method of the ruthenium-based catalyst is characterized by comprising the following steps:

obtaining a carrier;

and adding a solution containing an active metal element precursor into the carrier, roasting I, and reducing to obtain the ruthenium-based catalyst.

Optionally, the method for obtaining the vector comprises: TiO 2₂Roasting the precursor II to obtain TiO₂And (3) a carrier.

Alternatively, the TiO₂The precursor is metatitanic acid or is prepared from a titanium source by at least one of a precipitation method, a sol-gel method, a hydrolysis method and a hydrothermal method; the titanium source is at least one of titanium tetrachloride, titanyl sulfate, titanium sulfate and titanium alkoxide.

Optionally, the roasting temperature of the roasting II is 300-900 ℃, and the roasting time is 2-24 hours.

Optionally, the upper limit of the temperature of roasting II is selected from 350 ℃, 400 ℃, 450 ℃, 500 ℃, 550 ℃, 600 ℃, 650 ℃, 700 ℃, 750 ℃, 800 ℃, 850 ℃ or 900 ℃; the lower limit is selected from 300 deg.C, 350 deg.C, 400 deg.C, 450 deg.C, 500 deg.C, 550 deg.C, 600 deg.C, 650 deg.C, 700 deg.C, 750 deg.C, 800 deg.C or 850 deg.C.

Alternatively, the upper limit of the time of calcination II is selected from 3 hours, 4 hours, 5 hours, 8 hours, 10 hours, 12 hours, 15 hours, 18 hours, 20 hours, 22 hours, or 24 hours; the lower limit is selected from 2 hours, 3 hours, 4 hours, 5 hours, 8 hours, 10 hours, 12 hours, 15 hours, 18 hours, 20 hours, or 22 hours.

Optionally, the roasting temperature of the roasting II is 450-800 ℃, and the roasting time is 4-10 hours.

Optionally, the temperature rise rate of the roasting II is 1-10 ℃/min.

Optionally, the heating rate of the roasting II is 5 ℃/min.

Optionally, the method for obtaining the vector comprises: TiO 2₂Roasting the precursor II, grinding, tabletting, crushing and sieving to obtain TiO₂And (3) a carrier.

Optionally, the pressure of the tablet is 10-25 Mpa.

Optionally, the pressure of the compressed tablet is 20 Mpa.

Optionally, the particle size of the carrier is 40-60 mesh.

Optionally, the mass ratio of the active metal to the carrier in the active metal element precursor-containing solution is 1: 100-1: 10.

Optionally, the concentration of the solution containing the active metal element precursor is 10mg/ml to 30 mg/ml.

Optionally, the conditions of the roasting I are as follows: keeping the temperature at 200-700 ℃ for 1-10 hours.

Optionally, the conditions of the roasting I are as follows: keeping the temperature of the mixture at 200-700 ℃ for 1-10 hours in a nitrogen or air atmosphere.

Optionally, the conditions of the roasting I are as follows: keeping the temperature at 400-500 ℃ for 2-6 hours.

Optionally, the conditions of the roasting I are as follows: keeping the temperature of the mixture at 400-500 ℃ for 2-6 hours in a nitrogen or air atmosphere.

Optionally, the upper limit of the temperature of the roasting I is selected from 250 ℃, 300 ℃, 350 ℃, 400 ℃, 450 ℃, 500 ℃, 550 ℃, 600 ℃, 650 ℃ or 700 ℃; the lower limit is selected from 200 deg.C, 250 deg.C, 300 deg.C, 350 deg.C, 400 deg.C, 450 deg.C, 500 deg.C, 550 deg.C, 600 deg.C or 650 deg.C.

Alternatively, the upper limit of the time of calcination I is selected from 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, or 10 hours; the lower limit is selected from 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, or 9 hours.

Optionally, the reducing conditions are: keeping the temperature of the mixture at 200-600 ℃ for 0.5-8 hours in a hydrogen-containing atmosphere.

Optionally, the reducing conditions are: keeping the temperature at 300-500 ℃ for 1-6 hours in a hydrogen-containing atmosphere.

Optionally, the reducing conditions are: keeping the temperature of the mixture at 200-600 ℃ for 0.5-8 hours in a hydrogen atmosphere.

Optionally, the reducing conditions are: keeping the temperature at 300-500 ℃ for 1-6 hours in a hydrogen atmosphere.

Optionally, the active metal element precursor is selected from at least one of active metal element precursor salts.

Optionally, the active metal element precursor salt solution is selected from at least one of a precursor salt of Ru, a precursor salt of Pd, a precursor salt of Pt, a precursor salt of Mn, a precursor salt of Co, a precursor salt of Ni, a precursor salt of Cu, and a precursor salt of Ce.

Optionally, the precursor salt of Ru is selected from at least one of ruthenium trichloride, ruthenium nitrate and ruthenium nitrosyl nitrate.

Optionally, the precursor salt of Pd is selected from at least one of palladium chloride, palladium nitrate and chloropalladic acid.

Optionally, the precursor salt of Pt is selected from at least one of platinum chloride, platinum nitrate and chloroplatinic acid.

Optionally, the precursor salt of Mn, Co, Ni, Cu is selected from at least one of nitrate, hydrochloride, acetate, and sulfate.

Optionally, the precursor salt of Ce is selected from at least one of cerium nitrate, cerium chloride and ammonium cerium nitrate.

Optionally, adding a solution containing an active metal element precursor to the carrier, drying, roasting I, and reducing to obtain the ruthenium-based catalyst.

Optionally, the drying conditions are: drying the mixture for 3 to 15 hours at a temperature of between 60 and 140 ℃.

Optionally, the upper limit of the temperature of the drying is selected from 70 ℃, 80 ℃, 90 ℃, 100 ℃, 110 ℃, 120 ℃, 130 ℃ or 140 ℃; the lower limit is selected from 60 deg.C, 70 deg.C, 80 deg.C, 90 deg.C, 100 deg.C, 110 deg.C, 120 deg.C or 130 deg.C.

Optionally, the upper limit of the time of drying is selected from 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, 13 hours, 14 hours, or 15 hours; the lower limit is selected from 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, 13 hours, or 14 hours.

Optionally, the drying conditions are: drying for 6-12 hours at 80-120 ℃.

As an embodiment, Ru/TiO₂The preparation method of the catalyst comprises the following specific steps:

support TiO₂The preparation of (1): preparing TiO from titanium sources such as titanium tetrachloride, titanyl sulfate or titanium sulfate and titanium alkoxide by a precipitation method, a sol-gel method, a hydrolysis method or a hydrothermal method₂The precursor or metatitanic acid is put into a muffle furnace to be roasted for n hours at the temperature of m ℃, the heating rate is 5 ℃/min, and rutile and anatase mixed phase TiO is obtained_2-m-nThe carrier (m is the calcination temperature and n is the calcination time). Fully grinding the carrier, and pressing the carrier into a sheet under 20MPa for molding; pulverizing, sieving, and collecting 40-60 mesh granules. The roasting temperature m is 300-900 ℃, preferably 450-800 ℃. The calcination time n is 2-24h, preferably 4-10 h.

Ru_xN_1-x/TiO_2-m-nPreparation of the catalyst:

1) preparing precursor salt solution of Ru, Pd, Pt, Mn, Co, Ni, Cu and Ce in a certain ratio;

2) dropwise adding the salt water solution obtained in the step 1) into TiO_2-m-nDrying, roasting and reducing to obtain the TiO₂A supported catalyst;

the drying process comprises the following steps: drying for 3-15 hours at 60-140 ℃, preferably drying for 6-12 hours at 80-120 ℃; the roasting process comprises the following steps: keeping the temperature of the mixture at 200-700 ℃ for 1-10 hours in a nitrogen or air atmosphere, preferably at 400-500 ℃ for 2-6 hours;

the reduction process comprises the following steps: keeping the temperature of the mixture at 200-600 ℃ for 0.5-8 hours in a hydrogen atmosphere, preferably at 300-500 ℃ for 1-6 hours.

According to still another aspect of the present application, there is provided a catalyst for catalytic removal of VOCs, comprising at least one of the ruthenium-based catalyst, the ruthenium-based catalyst prepared according to the method.

According to yet another aspect of the present application, a method for catalytic removal of gases of VOCs is provided.

The method for catalytically removing the VOCs gas is characterized in that the VOCs gas is subjected to combustion reaction by taking oxygen as an oxidant in the presence of a catalyst; the temperature of the combustion reaction is 100-700 ℃;

the catalyst is at least one selected from the ruthenium-based catalyst, the ruthenium-based catalyst prepared by the method and the VOCs catalytic removal catalyst.

Optionally, the VOCs gas includes at least one of benzene, halogenated hydrocarbon, ester, and acid.

Optionally, the VOCs gas comprises at least one of toluene, meta-xylene, methyl bromide, methyl acetate, ethyl acetate, and acetic acid.

The beneficial effects that this application can produce include:

1) the ruthenium-based catalyst provided by the application has the advantages that the price of the used noble metal Ru is lower than that of other noble metals (Pt, Pd and Rh), and secondary pollution is avoided; the preparation process of the catalyst is simple and easy for large-scale production;

2) the ruthenium-based catalyst provided by the application has higher activity and stability to halogenated hydrocarbon, low reaction activation temperature and better anti-poisoning performance;

3) the ruthenium-based catalyst provided by the application has high catalytic activity on halogenated hydrocarbon and good catalytic activity on benzene similar substances, so that the catalyst has certain universality.

Drawings

FIG. 1 shows catalyst CH prepared in examples and comparative examples₃Br catalytic combustion activity;

FIG. 2 shows catalyst CH prepared in examples and comparative examples₃Br catalytic combustion activity;

FIG. 3 shows catalytic combustion activity of m-xylene in catalysts prepared in examples and comparative examples;

FIG. 4 shows catalyst CH obtained in example 2₃Br catalytic combustion stability;

FIG. 5 is a powder X-ray diffraction pattern of the carrier obtained in example.

Detailed Description

The present application will be described in detail with reference to examples, but the present application is not limited to these examples.

The raw materials in the examples of the present application were all purchased commercially, unless otherwise specified.

Titanium tetrachloride, a titanium source, was purchased from alatin; titanyl sulfate was purchased from alatin; titanium sulfate was purchased from alatin; titanium alkoxides are available from alatin.

The titanium source is prepared into TiO by a precipitation method, a sol-gel method, a hydrolysis method or a hydrothermal method₂And (3) precursor.

Metatitanic acid was purchased from luxurious Industrial and trade company, Panzhihua.

Example 1

10g of metatitanic acid is put into a muffle furnace to be roasted for 5 hours at the temperature of 550 ℃, and the heating rate is 5 ℃/min. Fully grinding the carrier, and pressing the carrier into a sheet under 20MPa for molding; pulverizing, sieving, and collecting 40-60 mesh granules. 0.54ml of an aqueous solution of ruthenium trichloride with a concentration of 18.76mg of Ru/ml is taken and added dropwise to 1g of solid TiO_2-550-5. The resulting solid was placed in an oven at 110 ℃ for 12 hours. Roasting the dried solid at 450 deg.C for 3 hr under air atmosphere, and reducing at 300 deg.C for 1 hr under hydrogen atmosphere to obtain 1%

Ru/TiO_2-550-5A catalyst.

Example 2

10g of titanium hydroxide prepared by a homogeneous precipitation method of titanium sulfate is put into a muffle furnace and roasted at 650 ℃ for 5 hours, and the heating rate is 5 ℃/min. Fully grinding the carrier, and pressing the carrier into a sheet under 20MPa for molding; pulverizing, sieving, and collecting 40-60 mesh granules. 0.54ml of an aqueous solution of ruthenium trichloride with a concentration of 18.76mg of Ru/ml is taken and added dropwise to 1g of solid TiO_2-650-5. The resulting solid was placed in an oven at 110 ℃ for 12 hours. Roasting the dried solid at 450 ℃ for 3 hours in an air atmosphere, and reducing the solid at 300 ℃ for 1 hour in a hydrogen atmosphere to obtain 1% Ru/TiO_2-650-5A catalyst.

Example 3

10g of TiO prepared by sol-gel method by using titanium isopropoxide as a titanium source₂The precursor is put into a muffle furnace to be roasted for 5 hours at the temperature of 750 ℃, and the heating rate is 5 ℃/min. Fully grinding the carrier, and pressing the carrier into a sheet under 20MPa for molding; pulverizing, sieving, and collecting 40-60 mesh granules. Taking 0.54ml of the extract as18.76mg Ru/ml aqueous ruthenium trichloride solution, which was added dropwise to 1g of solid TiO_2-750-5. The resulting solid was placed in an oven at 110 ℃ for 12 hours. Roasting the dried solid at 450 ℃ for 3 hours in an air atmosphere, and reducing the solid at 300 ℃ for 1 hour in a hydrogen atmosphere to obtain 1% Ru/TiO_2-750-5A catalyst.

Example 4

10g of titanium hydroxide prepared by a homogeneous precipitation method of titanium sulfate is put into a muffle furnace and roasted at 650 ℃ for 5 hours, and the heating rate is 5 ℃/min. Fully grinding the carrier, and pressing the carrier into a sheet under 20MPa for molding; pulverizing, sieving, and collecting 40-60 mesh granules. 0.43ml of an aqueous solution of ruthenium trichloride having a concentration of 18.76mg Ru/ml and 0.11ml of a solution of chloroplatinic acid having a concentration of 18.76mg Pt/ml were taken and added dropwise to 1g of solid TiO_2-650-5. The resulting solid was placed in an oven at 110 ℃ for 12 hours. Roasting the dried solid at 450 ℃ for 3 hours in an air atmosphere, and reducing the solid at 300 ℃ for 1 hour in a hydrogen atmosphere to obtain 0.8 percent Ru-0.2 percent Pt/TiO_2-650-5A catalyst.

Example 5

10g of metatitanic acid is put into a muffle furnace to be roasted for 5 hours at the temperature of 550 ℃, and the heating rate is 5 ℃/min. Fully grinding the carrier, and pressing the carrier into a sheet under 20MPa for molding; pulverizing, sieving, and collecting 40-60 mesh granules. 0.32ml of an aqueous solution of ruthenium trichloride at a concentration of 18.76mg Ru/ml, 0.11ml of a solution of chloroplatinic acid at a concentration of 18.76mg Pt/ml and 0.11ml of a solution of chloroplatinic acid at a concentration of 18.76mg Pd/ml were taken and the solutions were added dropwise to 1g of solid TiO_2-550-5. The resulting solid was placed in an oven at 110 ℃ for 12 hours. Roasting the dried solid at 450 ℃ for 3 hours in an air atmosphere, and reducing the solid at 300 ℃ for 1 hour in a hydrogen atmosphere to obtain 0.6% Ru-0.2% Pt-0.2 Pd%/TiO_2-550-5A catalyst.

Example 6

10g of TiO prepared by sol-gel method by using titanium isopropoxide as a titanium source₂The precursor is put into a muffle furnace to be roasted for 5 hours at the temperature of 750 ℃, and the heating rate is 5 ℃/min. Fully grinding the carrier, and pressing the carrier into a sheet under 20MPa for molding; pulverizing, sieving, and collecting 40-60 mesh granules. 0.54ml of a ruthenium trichloride aqueous solution having a concentration of 18.76mg Ru/ml and 1ml of a mixed solution (0.5M cobalt nitrate, 0.5M manganese nitrate, 0.5M nitric acid)Copper) was added dropwise to 1g of solid TiO_2-750-5. The resulting solid was placed in an oven at 110 ℃ for 12 hours. Roasting the dried solid at 450 deg.C for 3 hr under air atmosphere, and reducing at 300 deg.C for 1 hr under hydrogen atmosphere to obtain 1%

Ru-4％Co₃O₄-3.5％Mn₂O₃-3.5％CuO/TiO_2-750-5A catalyst.

Example 7

The specific operation is the same as that of example 1, except that a certain amount of metatitanic acid is put into a muffle furnace to be roasted at 300 ℃ for 24 hours, and the heating rate is 5 ℃/min. Obtaining 1% Ru/TiO_2-300-24Catalyst-1.

The specific operation is the same as that of example 1, except that a certain amount of metatitanic acid is put into a muffle furnace to be roasted at 900 ℃ for 2 hours, and the heating rate is 5 ℃/min. Obtaining 1% Ru/TiO_2-900-2Catalyst-2.

The procedure is as in example 1, except that the solid obtained is dried in an oven at 60 ℃ overnight for 15 hours. Obtaining 1% Ru/TiO_2-550-5Catalyst-3.

The procedure is as in example 1, except that the solid obtained is dried in an oven at 140 ℃ for 3 hours. Obtaining 1% Ru/TiO_2-550-5Catalyst-4.

The procedure is as in example 1, except that the solid obtained is dried in an oven at 60 ℃ overnight for 15 hours. Obtaining 1% Ru/TiO_2-550-5Catalyst-5.

The procedure was as in example 1, except that the dried solid was calcined at 200 ℃ for 10 hours in an air atmosphere and reduced at 600 ℃ for 0.5 hour in a hydrogen atmosphere. Obtaining 1% Ru/TiO_2-550-5Catalyst-6.

The procedure is as in example 1, except that the dried solid is calcined at 700 ℃ for 1 hour in an air atmosphere and reduced at 200 ℃ for 8 hours in a hydrogen atmosphere. Obtaining 1% Ru/TiO_2-550-5Catalyst-7.

The procedure is as in example 1, except that the dried solid is calcined at 700 ℃ for 1 hour under a nitrogen atmosphere and reduced at 200 ℃ for 8 hours under a hydrogen atmosphere. Obtaining 1% Ru/TiO_2-550-5Catalyst-7.

Example 8

The crystal form of the carriers of examples 1 to 6 was tested on a RigakuD/MAX-RB powder X-ray diffractometer of Japan, using CuK α as a light source, the tube voltage was 40KV, the tube current was 200mA, the scanning speed was 5 °/min, and the scanning range was 10 to 80 °. As shown in FIG. 5, it was shown that TiO prepared by different methods from different titanium sources₂Some difference in crystalline phase, unless TiO is detected₂No active component was detected outside the crystal phase, indicating that the active component was in TiO₂The upper part is highly dispersed.

The powder X-ray diffraction pattern of the support of the catalyst prepared in example 7 was similar to that of example 1.

Comparative example 1

10g of titanium hydroxide prepared by a homogeneous precipitation method of titanium sulfate is put into a muffle furnace and roasted at 650 ℃ for 5 hours, and the heating rate is 5 ℃/min. Fully grinding the carrier, and pressing the carrier into a sheet under 20MPa for molding; pulverizing, sieving, and collecting 40-60 mesh granules. 0.54ml of a solution of chloroplatinic acid having a concentration of 18.76mg Pt/ml was taken and added dropwise to 1g of solid TiO_2-650-5. The resulting solid was placed in an oven at 110 ℃ overnight. Roasting the dried solid at 450 ℃ for 3 hours in an air atmosphere, and reducing the solid at 300 ℃ for 1 hour in a hydrogen atmosphere to obtain 1% Pt/TiO_2-650-5A catalyst.

Comparative example 2

10g of titanium hydroxide prepared by a homogeneous precipitation method of titanium sulfate is put into a muffle furnace and roasted at 650 ℃ for 5 hours, and the heating rate is 5 ℃/min. Fully grinding the carrier, and pressing the carrier into a sheet under 20MPa for molding; pulverizing, sieving, and collecting 40-60 mesh granules. 0.54ml of a palladium nitrate solution having a concentration of 18.76mgPd/ml was taken and added dropwise to 1g of solid TiO_2-650-5. The resulting solid was placed in an oven at 110 ℃ for 1 overnight. Roasting the dried solid at 450 ℃ for 3 hours in an air atmosphere, and reducing the roasted solid at 300 ℃ for 1 hour in a hydrogen atmosphere to obtain 1% Pd/TiO_2-650-5A catalyst.

Comparative example 3

Fully grinding 10g of industrial aluminum oxide, and pressing the industrial aluminum oxide into sheets under 20MPa for molding; pulverizing, sieving, and collecting 40-60 mesh granules. 0.41ml of an aqueous ruthenium trichloride solution having a concentration of 24.4mg of Ru/ml was taken, and this solution was added dropwise to 1g of solid aluminum oxide. The resulting solid was placed in an oven at 110 ℃ overnight. Roasting the dried solid at 450 ℃ for 3 hours in an air atmosphere, and reducing the roasted solid at 300 ℃ for 1 hour in a hydrogen atmosphere to obtain 1% Ru/Al₂O₃A catalyst.

Comparative example 4

Adding 10ga-TiO₂Fully grinding (anatase) and pressing and forming under 20 MPa; pulverizing, sieving, and collecting 40-60 mesh granules. 0.625ml of an aqueous solution of ruthenium trichloride with a concentration of 16mg Ru/ml is taken and added dropwise to 1g of solid a-TiO₂. The resulting solid was placed in an oven at 110 ℃ overnight. Roasting the dried solid at 450 ℃ for 3 hours in an air atmosphere, and reducing the solid at 300 ℃ for 1 hour in a hydrogen atmosphere to obtain 1 percent Ru/a-TiO₂A catalyst.

Comparative example 5

Mixing 10gr-TiO₂Fully grinding (rutile) and pressing into sheets under 20MPa for forming; pulverizing, sieving, and collecting 40-60 mesh granules. 0.54ml of an aqueous solution of ruthenium trichloride with a concentration of 18.76mg of Ru/ml is taken and added dropwise to 1g of solid r-TiO₂. The resulting solid was placed in an oven at 110 ℃ overnight. Roasting the dried solid at 450 ℃ for 3 hours in an air atmosphere, and reducing the solid at 300 ℃ for 1 hour in a hydrogen atmosphere to obtain 1 percent Ru/r-TiO₂A catalyst.

Fig. 1 and 2 show catalytic activity of methyl bromide, and the specific test conditions are as follows: CH (CH)₃Br concentration 400ppm, balance air, total flow 500mL^-1Reaction mass space velocity of 120,000mL. h^-1·g^-1(ii) a FIG. 1 shows that the initial activity is better for the catalytic oxidation of methyl bromide in examples 2, 3 and 5, but the activity of examples 3 and 5 is lower than that of example 2 with the increase of the reaction temperature, and the catalytic activity of example 2 is the best; FIG. 2 shows that example 2 is the most active, i.e. the same TiO₂The carrier is obviously superior to Pt and Pd for catalytic oxidation of Ru by methyl bromide. Table 1 shows the temperatures required for the catalytic conversion of bromomethane by the catalysts to 10%, 50% and 90%; the data in Table 1 show T for example 2₁₀、T₅₀、T₉₀All are the lowest, i.e. the best catalytic activity on methyl bromide. FIG. 3 shows the catalytic activity of m-xylene, under the following specific test conditions: the concentration of m-xylene is 400ppm, the rest is air, and the total flow is 500mL^-1Reaction mass space velocity of 120,000mL h^-1g^-1(ii) a Figure 3 shows that catalytic oxidation of meta-xylene is significantly better for example 2 than for comparative example 3. The stability results are shown in figure 4; FIG. 4 shows that the activity of the catalyst is still maintained above 99% after the reaction is stabilized at 280 ℃ for 38h, which shows that the catalyst has better anti-poisoning performance. TABLE 1

Although the present application has been described with reference to a few embodiments, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the application as defined by the appended claims.

Claims

1. A ruthenium-based catalyst, characterized in that the ruthenium-based catalyst comprises a support and an active component;

the active component comprises an active metal element;

the active metal element is Ru;

2. The catalyst according to claim 1, wherein the active component is present in the ruthenium-based catalyst in an amount of 0.01 to 10% by mass;

3. The catalyst according to claim 1, characterized in that the active component further comprises an element M;

the element M is at least one selected from Pd, Pt, Mn, Co, Ni, Cu and Ce;

the weight ratio of M to Ru is 0: 1-20: 1.

4. the ruthenium-based catalyst according to claim 1, wherein the rutile phase is present in the support in an amount greater than 30% by weight;

preferably, the rutile content in the carrier is 50% to 70% by weight;

preferably, the TiO is₂The crystal form is a mixed crystal form of anatase, rutile and brookite.

5. A method for preparing a ruthenium-based catalyst according to any one of claims 1 to 4, comprising the steps of:

obtaining a carrier;

6. The method according to claim 5, wherein the carrier is obtained by a method comprising: TiO 2₂Roasting the precursor II to obtain TiO₂A carrier;

preferably, the roasting temperature of the roasting II is 300-900 ℃, and the roasting time is 2-24 hours;

preferably, the roasting temperature of the roasting II is 450-800 ℃, and the roasting time is 4-10 hours;

preferably, the temperature rise rate of the roasting II is 1-10 ℃/min;

preferably, the particle size of the carrier is 40-60 mesh.

7. The method according to claim 5, wherein the mass ratio of the active metal to the carrier in the solution containing the active metal element precursor is 1:100 to 1: 10;

preferably, the concentration of the solution containing the precursor of the active metal element is 10 mg/ml-30 mg/ml;

preferably, the conditions of the roasting I are as follows: keeping the temperature at 200-700 ℃ for 1-10 hours;

preferably, the conditions of the roasting I are as follows: keeping the temperature of the mixture at 400-500 ℃ for 2-6 hours;

preferably, the reduction conditions are: keeping the temperature of the mixture for 0.5 to 8 hours at 200 to 600 ℃ in a hydrogen-containing atmosphere;

preferably, the reduction conditions are: keeping the temperature at 300-500 ℃ for 1-6 hours in a hydrogen-containing atmosphere;

preferably, the active metal element precursor is selected from at least one of active metal element precursor salts;

preferably, the active metal element precursor salt solution is selected from at least one of a precursor salt of Ru, a precursor salt of Pd, a precursor salt of Pt, a precursor salt of Mn, a precursor salt of Co, a precursor salt of Ni, a precursor salt of Cu, and a precursor salt of Ce;

preferably, the precursor salt of Ru is selected from at least one of ruthenium trichloride, ruthenium nitrate and nitrosyl ruthenium nitrate;

preferably, the precursor salt of Pd is selected from at least one of palladium chloride, palladium nitrate and chloropalladic acid;

preferably, the precursor salt of Pt is selected from at least one of platinum chloride, platinum nitrate and chloroplatinic acid;

preferably, the precursor salt of Mn, Co, Ni and Cu is selected from at least one of nitrate, hydrochloride, acetate and sulfate;

preferably, the precursor salt of Ce is selected from at least one of cerium nitrate, cerium chloride and ammonium cerium nitrate.

8. A catalyst for catalytic removal of VOCs comprising at least one of the ruthenium-based catalyst according to any one of claims 1 to 4, the ruthenium-based catalyst prepared according to the process of any one of claims 5 to 7.

9. A method for catalytically removing VOCs gas is characterized in that the VOCs gas is subjected to combustion reaction by taking oxygen as an oxidant in the presence of a catalyst; the temperature of the combustion reaction is 100-700 ℃;

the catalyst is selected from at least one of ruthenium-based catalysts according to any one of claims 1 to 4, ruthenium-based catalysts prepared according to the process of any one of claims 5 to 7, and catalysts for the catalytic removal of VOCs according to claim 8.

10. The method of claim 9, wherein the VOCs gas comprises at least one of benzene, halogenated hydrocarbons, esters, and acids.