阅读说明：本技术 贵金属催化剂及其制备方法、应用 (Noble metal catalyst and preparation method and application thereof ) 是由 刘俊义 王树东 崔艳斌 苏宏久 郭翔 杨晓野 付鹏兵 李大卫 吴伟 严华 刘志 于 2019-01-16 设计创作，主要内容包括：本申请公开了一种贵金属催化剂及其制备方法、应用。该催化剂包括载体和活性组分；所述活性组分负载在所述载体上；所述载体包括有机基团修饰的氧化硅；所述活性组分包括活性元素；所述活性元素选自Pd、Pt中的至少一种。该加氢催化剂通过对氧化硅载体引入有机基团,调节载体的疏水性及极性,避免了加氢工作液中的水对活性组分的水化作用,而且进一步提高了蒽醌加氢后的物种-蒽氢醌的脱附作用,提高了加氢催化剂的选择性和稳定性。本发明催化剂可用于浆态床蒽醌催化加氢生产双氧水过程中,加氢催化剂表现出很高的加氢选择性和稳定性。(The application discloses a noble metal catalyst, a preparation method and application thereof. The catalyst comprises a carrier and an active component; the active component is loaded on the carrier; the support comprises silica modified with organic groups; the active component comprises an active element; the active element is at least one of Pd and Pt. The hydrogenation catalyst has the advantages that organic groups are introduced into the silicon oxide carrier, the hydrophobicity and the polarity of the carrier are adjusted, the hydration effect of water in the hydrogenation working solution on active components is avoided, the desorption effect of anthraquinone-hydrogenated species-anthrahydroquinone is further improved, and the selectivity and the stability of the hydrogenation catalyst are improved. The catalyst can be used in the process of producing hydrogen peroxide by catalytic hydrogenation of anthraquinone in a slurry bed, and the hydrogenation catalyst shows high hydrogenation selectivity and stability.)

1. A noble metal catalyst comprising a support and an active component;

the active component is loaded on the carrier;

the support comprises silica modified with organic groups;

the active component comprises an active element;

the active element is at least one of Pd and Pt.

2. The noble metal catalyst according to claim 1, wherein the mass content of the active component in the noble metal catalyst is 0.01 to 2.00 wt%, and the mass content of Pd in the active component is 50 to 100 wt%;

wherein the content of the active component is calculated by the content of active elements;

the content of Pd is calculated as the content of Pd element itself.

3. The noble metal catalyst of claim 1 wherein the organic group comprises C₁～C₁₈Hydrocarbyl radical, C₁～C₁₈At least one of groups formed by substituting at least one carbon atom in the hydrocarbon group with a heteroatom;

wherein the heteroatom is selected from at least one of oxygen, nitrogen and sulfur.

4. The noble metal catalyst according to claim 1, wherein the noble metal catalyst has a particle size of 20 to 300 μm, an average pore diameter of 10 to 30nm, a pore volume of less than 0.75cc/g, and a specific surface area of 140 to 180m²/g；

The carrier is spherical silicon oxide modified by the organic group;

in the carrier, the mass ratio of the organic group to the spherical silica is 3-20: 100.

5. the method for producing a noble metal catalyst according to any one of claims 1 to 4, wherein an oxidized precursor is prepared from a silica sol containing an organic group and a precursor containing an active element, and the oxidized precursor is reduced to obtain the noble metal catalyst;

wherein the silica sol containing organic groups refers to SiO modified by organic groups₂The sol formed.

6. The method of claim 5, wherein the oxidized form precursor is obtained by:

method 1

a1) Forming the silica sol containing organic groups to obtain a silica carrier;

a2) loading the precursor containing the active elements on the silicon oxide carrier, and roasting I to obtain the oxidation state precursor; or

Method 2

b1) Forming a mixture formed by the precursor containing the active elements and the silica sol containing the organic groups, and roasting II to obtain the oxidation state precursor;

preferably, the means of shaping comprises spray drying;

preferably, the roasting temperature of the roasting I and the roasting II is 200-300 ℃ independently, and the roasting time is 1-5 hours independently.

7. The preparation method according to claim 5, wherein the silica sol has a particle size of 10 to 100nm, and a solid content of 10 to 50 wt%;

wherein the solid content of the silica sol is SiO₂The mass percentage of the silicon sol;

preferably, the particle size of the silica sol is 15-70 nm, and the solid content of the silica sol is 15-40 wt%.

8. The production method according to claim 5, wherein the precursor containing an active element includes a salt compound containing an active element;

the salt compound containing the active element is at least one selected from platinum acetate, platinum propionate, palladium (II) acetate, palladium (II) propionate, palladium (II) 2-methyl propionate and palladium trimethyl acetate.

9. The method of claim 5, wherein the reducing conditions are: reducing for 5-6 h at 80-100 ℃, wherein the reducing atmosphere is hydrogen.

10. A method for preparing hydrogen peroxide by anthraquinone hydrogenation in a slurry bed is characterized in that a noble metal catalyst according to any one of claims 1 to 4 and a noble metal catalyst prepared by the method according to any one of claims 5 to 9 are used for catalyzing the hydrogenation reaction of anthraquinone;

preferably, the anthraquinone is selected from at least one of ethylanthraquinone, amylanthraquinone, ethyltetrahydroanthraquinone, amyltetrahydroanthraquinone.

Technical Field

The application relates to a noble metal catalyst, a preparation method and application thereof, and belongs to the technical field of chemical production.

Background

The final product decomposed in the using process of the hydrogen peroxide is mainly water, secondary pollutants can not be generated, and the hydrogen peroxide is an environment-friendly chemical. As a green chemical product, the hydrogen peroxide can be used as an oxidant, a bleaching agent, a disinfectant, a polymer initiator and the like, and is widely applied to the industries of chemical synthesis, papermaking, spinning, environmental protection, food, electronics, aerospace and the like.

The anthraquinone process is the main process for producing hydrogen peroxide in the world at present. In the anthraquinone hydrogenation process, the most important step is the hydrogenation process of the anthraquinone, and the solid catalyst has great influence on the energy consumption and the material consumption of an anthraquinone hydrogenation system.

Drelinkiewicz et al, Bowland scientific institute, propose (Chemical Papers,2013,67(8), 1087-.

Therefore, how to realize a hydrogenation catalyst with high selectivity, high activity and high stability is still a great challenge.

Disclosure of Invention

According to one aspect of the application, the hydrogenation catalyst disclosed by the application is characterized in that organic groups are introduced into a silicon oxide carrier, the hydrophobicity and the polarity of the carrier are adjusted, the hydration effect of water in a hydrogenation working solution on active components is avoided, the desorption effect of anthraquinone-hydrogenated anthraquinone is further improved, and the selectivity and the stability of the hydrogenation catalyst are improved.

According to an aspect of the present application, there is provided a noble metal catalyst comprising a support and an active component; the active component is loaded on the carrier; the support comprises silica modified with organic groups; the active component comprises an active element; the active element is at least one of Pd and Pt.

Aiming at the dispersibility of the noble metal active component of the hydrogenation catalyst and the hydrophobicity of the catalyst carrier in the anthraquinone hydrogenation process, the application provides that the silicon oxide containing organic functional group hydrophobicity is used as the carrier to regulate the type and the quantity of the organic functional group and regulate the hydrophobicity of the silicon oxide carrier, and the activity and the stability of the hydrogenation catalyst are improved through the regulation and control of the physical parameters of the silicon oxide carrier; and after the surface of the silicon oxide is regulated and controlled by organic functional groups, the desorption of anthrahydroquinone species is improved, the selectivity of anthraquinone hydrogenation reaction is improved, and the hydrogenation stability is further improved.

Optionally, the mass content of the active component in the noble metal catalyst is 0.01-2.00 wt%, and the mass content of Pd in the active component is 50-100 wt%; wherein the content of the active component is calculated by the content of active elements; the content of Pd is calculated as the content of Pd element itself.

The upper limit of the mass content of the active component in the noble metal catalyst is selected from 0.4 wt%, 2.00 wt%, and the lower limit of the mass content of the active component in the noble metal catalyst is selected from 0.01 wt%, 0.4 wt%.

The upper limit of the mass content of Pd in the active component is selected from 55 wt%, 60 wt%, 70 wt%, 80 wt%, 90 wt%, 100 wt%, and the lower limit of the mass content of Pd in the active component is selected from 50 wt%, 55 wt%, 60 wt%, 70 wt%, 80 wt%, 90 wt%.

Alternatively, the organic group comprises C₁～C₁₈Hydrocarbyl radical, C₁～C₁₈At least one of groups formed by substituting at least one carbon atom in the hydrocarbon group with a heteroatom; wherein the heteroatom is selected from at least one of oxygen, nitrogen and sulfur.

Preferably, the organic group comprises C₁～C₆A hydrocarbon group, and C₁～C₆At least one of the groups formed by substituting at least one carbon atom of the hydrocarbon group with a heteroatom.

Specifically, the organic group may be methyl, ethyl, propyl, phenyl, phenethyl, benzyl, acetyl, propionyl, fluoroalkyl, pyridyl, or the like.

When the hydrocarbon group contains a heteroatom, atoms such as oxygen, nitrogen, sulfur, etc. should be internal to the organic group, which can adjust the hydrophobicity of the silica support.

Optionally, the noble metal catalyst has a particle size of 20 to 300 μm, an average pore diameter of 10 to 30nm, a pore volume of less than 0.75cc/g, and a specific surface area of 140 to 180m²/g；

The carrier is spherical silicon oxide modified by the organic group;

in the carrier, the mass ratio of the organic group to the spherical silica is 3-20: 100.

according to another aspect of the present application, there is also provided a method for preparing a noble metal catalyst, comprising preparing an oxidation state precursor from a silica sol containing an organic group and a precursor containing an active element, and reducing to obtain the noble metal catalyst; wherein the silica sol containing organic groups refers to SiO modified by organic groups₂The sol formed.

Optionally, the manner of obtaining the oxidized precursor comprises:

method 1

a1) Forming the silica sol containing organic groups to obtain a silica carrier;

a2) loading the precursor containing the active elements on the silicon oxide carrier, and roasting I to obtain an oxidation state compound I; or

Method 2

b1) Forming a mixture formed by the precursor containing the active elements and the silica sol containing the organic groups, and roasting II to obtain an oxidation state precursor;

specifically, the method 1 comprises:

1-1) preparing spherical particles from silica sol containing organic groups by a spray drying mode, and then drying to obtain a silicon oxide carrier;

1-2) loading a precursor containing active elements on the silicon oxide carrier obtained in the step 1-1), and drying and roasting I to prepare an oxidation state precursor;

the method 2 comprises the following steps:

2-1) adding the precursor with the active elements into silica sol containing organic groups, then obtaining particles in a spray drying mode, and then drying and roasting II to obtain an oxidation state precursor.

Optionally, the means of shaping comprises spray drying;

the roasting temperature of the roasting I and the roasting II is 200-300 ℃ independently, and the roasting time is 1-5 hours independently.

The method 1 and the method 2 are characterized in that the ball forming is carried out by utilizing a spray drying mode; the forming equipment is selected from centrifugal forming equipment; the dry gas is at least one of nitrogen, helium and carbon dioxide.

Specifically, in the present application, the molding apparatus may be a centrifugal molding apparatus, a pressure type molding apparatus, or a gas-liquid two-phase atomization type molding apparatus.

The upper limit of the roasting temperature of the roasting I and the roasting II is selected from 250 ℃ and 300 ℃, and the lower limit of the roasting temperature of the roasting I and the roasting II is selected from 200 ℃ and 250 ℃.

Optionally, the particle size of the silica sol is 10-100 nm; the solid content of the silica sol is 10-50 wt%. Wherein the solid content of the silica sol is SiO₂The mass percentage of the silicon sol.

Specifically, in the present application, the particle size of the silica sol refers to SiO that is not modified with organic groups₂The solid content in the silica sol refers to SiO which is not modified by organic groups₂Content in silica sol.

Preferably, the particle size of the silica sol containing organic groups is 15-70 nm, and the solid content in the silica sol is 15-40 wt%.

When the solid content of silica is more than 15%, the silica particles are easily formed into spherical particles, and when the solid content of silica is less than 40%, the preparation cost of the hydrophobic silica carrier is reduced.

In the present application, the mass fraction ratio of the solvent of the silica sol to water may be 0.1-12%, and the two solvents are mutually soluble, wherein the solvent may be selected from 1-pentanol (6.8% dissolved water), methyl ethyl ketone (9.9% dissolved water), methyl isopropyl ketone (1.8% dissolved water), cyclohexanone (8% dissolved water), ethyl acetate (2.9% dissolved water), n-butyl ethyl ester (1.9% dissolved water), methyl methacrylate (1.1% dissolved water), diisopropyl ether (0.55% dissolved water), dibutyl ether (0.2% dissolved water), and the like;

optionally, the precursor containing the active element comprises a salt compound containing the active element; the salt compound containing active elements is selected from platinum acetate (Pt (OAc)₂) Platinum propionate (Pt (O (C ═ O) CH)₂CH₃)₂) Palladium (II) acetate (Pd (OAc)₂) Palladium (II) propionate (Pd (O (C ═ O) CH)₂CH₃)₂) Palladium (II) 2-methylpropionate (Pd (O (C ═ O) CH (CH)₃)₂)₂) Palladium trimethyl acetate (Pd (OPiv))₂) At least one of (1).

Optionally, the reducing conditions are: reducing for 5-6 h at 80-100 ℃, wherein the reducing atmosphere is hydrogen.

The application also provides a method for preparing hydrogen peroxide by hydrogenating anthraquinone in a slurry bed, which uses the noble metal catalyst and the noble metal catalyst prepared by the method to catalyze the hydrogenation reaction of anthraquinone.

Optionally, the anthraquinone is selected from at least one of ethylanthraquinone, amylanthraquinone, ethyltetrahydroanthraquinone, amyltetrahydroanthraquinone.

In the present application, "C₁～C₁₈"all refer to the number of carbon atoms contained in a group.

The beneficial effects that this application can produce include:

1) the application provides a hydrophobic supported catalyst for producing hydrogen peroxide by anthraquinone hydrogenation and a preparation method thereof, which mainly improve the once-through hydrogen efficiency and the effective selectivity of anthraquinone, further improve the hydrogenation stability of the catalyst, and prevent the loss and inactivation of noble metals. According to the high-hydrophobicity supported slurry bed hydrogenation catalyst prepared in the application, the silicon oxide carrier containing the organic functional group has hydrophobicity, so that the interaction between water in a working solution and Pd particles in the catalyst is avoided, the hydrolysis resistance of active components of the catalyst can be improved, and the hydrogenation stability of the catalyst is improved; in addition, the silicon oxide carrier containing organic functional groups reduces the polarity of the surface of the catalyst, so that hydrogenated intermediate species generated by hydrogenation are easy to desorb from the inside of the catalyst, and the anthraquinone hydrogenation reaction is a complex reaction integrating series and parallel reactions, and the one-step hydrogenation reaction is an effective reaction for effective anthraquinone and tetrahydroanthraquinone, so that the anthrahydroquinone species can be easy to desorb by introducing the organic groups, the hydrogenation selectivity can be further improved, a large amount of byproducts are effectively avoided, the stability of the hydrogenation catalyst is improved, and the energy consumption of the reaction is reduced.

2) The catalyst can be used in the process of producing hydrogen peroxide by anthraquinone catalytic hydrogenation in a slurry bed, and has the reaction temperature of 40-60 ℃, the pressure of 0.05-0.3MPa and the liquid space velocity of 60-300h^-1Under the condition, the hydrogenation catalyst shows high hydrogenation selectivity and stability.

Drawings

FIG. 1 is an apparent topography of sample # 1;

FIG. 2 is a graph of the hydrogenation valence results for the examples of sample # 1, sample # 2, and sample # 6.

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.

In the present application, silica sols containing organic groups are purchased from Fuso, Grace.

Precursors containing active elements were purchased from the national pharmaceutical companies.