阅读说明：本技术 复合催化剂和醇醚羧酸盐的制备方法 (Composite catalyst and preparation method of alcohol ether carboxylate ) 是由 吕文章 李少林 于 2019-09-23 设计创作，主要内容包括：本发明涉及一种复合催化剂和醇醚羧酸盐的制备方法。该复合催化剂的制备方法包括以下步骤：(1)活性炭的预处理：将活性炭与活化试剂的水溶液在加热条件下反应,得预处理的活性炭；(2)将二价钯、二价非贵金属、盐酸和所得预处理的活性炭混合,反应；调节pH至碱性,加入还原剂,反应后分离,得复合催化剂；步骤(1)中所述活化试剂包括盐酸、硝酸和过氧化氢中的至少一种；步骤(2)中所述二价非贵金属包括二价镍、二价锡和二价钴中的至少一种。本发明方法制备得到的复合催化剂,其可以高转化率、高循环利用次数地催化醇醚合成醇醚羧酸盐。(The invention relates to a composite catalyst and a preparation method of alcohol ether carboxylate. The preparation method of the composite catalyst comprises the following steps: (1) pretreatment of activated carbon: reacting activated carbon with an aqueous solution of an activating reagent under a heating condition to obtain pretreated activated carbon; (2) mixing divalent palladium, divalent non-noble metal, hydrochloric acid and the obtained pretreated activated carbon, and reacting; adjusting pH to be alkaline, adding a reducing agent, reacting and separating to obtain a composite catalyst; the activating reagent in the step (1) comprises at least one of hydrochloric acid, nitric acid and hydrogen peroxide; the divalent non-noble metal in the step (2) comprises at least one of divalent nickel, divalent tin and divalent cobalt. The composite catalyst prepared by the method can catalyze alcohol ether to synthesize alcohol ether carboxylate with high conversion rate and high recycling times.)

1. The preparation method of the composite catalyst is characterized by comprising the following steps of:

(1) pretreatment of activated carbon: reacting activated carbon with an aqueous solution of an activating reagent under a heating condition to obtain pretreated activated carbon;

(2) mixing divalent palladium, divalent non-noble metal, hydrochloric acid and the obtained pretreated activated carbon, and reacting; adjusting pH to be alkaline, adding a reducing agent, reacting and separating to obtain a composite catalyst;

the activating reagent in the step (1) comprises at least one of hydrochloric acid, nitric acid and hydrogen peroxide;

the divalent non-noble metal in the step (2) comprises at least one of divalent nickel, divalent tin and divalent cobalt.

2. The method of claim 1, wherein the pretreatment of step (1) comprises: mixing the activated carbon with an aqueous solution of an activating reagent, refluxing for 2-6 h at 70-100 ℃, filtering, washing and drying.

3. The method as claimed in claim 1, wherein the mesh size of the activated carbon is 100-300 mesh.

4. The method according to claim 1, wherein the mass concentration of the activating reagent in the aqueous solution of the activating reagent in the step (1) is 5 to 20%.

5. The preparation method according to claim 4, wherein the mass-to-volume ratio of the activated carbon to the aqueous solution of the activating reagent in the step (1) is as follows: (1-10) g (50-200) ml.

6. The preparation method according to claim 1, wherein the mass ratio of the divalent palladium, the divalent non-noble metal and the pretreated activated carbon in the step (2) is as follows: (2-6):(2-6):(45-55).

7. The method according to claim 1, wherein in the step (2), the pH adjustment to alkalinity is: adjusting the pH value to 8-9; and/or, the reducing agent in the step (2) comprises at least one of sodium borohydride, formaldehyde, ethylene glycol and hydrogen.

8. A composite catalyst prepared by the method of any one of claims 1 to 7.

9. Use of the composite catalyst of claim 8 in the preparation of alcohol ether carboxylates.

10. The preparation method of the alcohol ether carboxylate is characterized by comprising the following steps:

(S1) mixing the alcohol ether and the composite catalyst of claim 8, adjusting the pH to be alkaline with an aqueous solution of alkali, and reacting;

(S2) the reaction solution is heated by introducing oxygen gas, and the reaction is carried out by solid-liquid separation to adjust the pH of the resulting solution to acidity.

11. The preparation method according to claim 10, wherein in the step (S1), the mass ratio of the alcohol ether to the composite catalyst is: 100:(1-20).

12. The production method according to any one of claims 10 to 11, wherein in the step (S1), the base is sodium hydroxide or potassium hydroxide.

13. The production method according to any one of claims 10 to 11, wherein in the step (S1), the pH is adjusted to 10 to 13; in the step (S2), the pH is adjusted to 1-2.

14. The production method according to any one of claims 10 to 11, characterized in that the alcohol ether is capped with ethylene oxide; and/or the alcohol ether comprises AEO-6, AEO-7, AEO-8, AEO-9, 350 or OE-10.

Technical Field

The invention relates to the field of chemical synthesis, in particular to a preparation method of a composite catalyst and alcohol ether carboxylate.

Background

The Alcohol Ether Carboxylate (AEC) is a novel anionic surfactant, has the characteristics of other anionic surfactants, such as low toxicity, easy biodegradation, low surface tension, good compatibility with other surfactants and the like, and is a multifunctional green surfactant. Due to its special properties, fatty alcohol ether carboxylates have found wide application in the fields of cosmetics, detergents, biochemistry, plastics, leather, pharmaceuticals, food processing and the petroleum industry.

The research on AEC in China has been carried out for more than ten years, and the main process routes are two kinds of AEC prepared by reacting sodium chloroacetate with alcohol ether and preparing AEC by catalytically oxidizing alcohol ether by noble metal. The preparation process of the sodium chloroacetate method is a solid-liquid reaction, the viscosity of a material system is high, the process amplification is difficult to a certain degree, the residual chloroacetic acid in the product is difficult to remove, and meanwhile, the chloroacetic acid has toxic action on a human body, so that the alcohol ether carboxylate prepared by the chloroacetic acid method is difficult to enter the daily chemical industry. The alcohol ether carboxylate prepared by the noble metal catalysis method is easy to lose and even inactivate when the catalyst is recycled due to high cost. Therefore, the alcohol ether carboxylic acid prepared by the existing noble metal oxidation method cannot be produced in an industrial large scale.

The general structural formula of the alcohol ether capable of being catalytically oxidized by using a metal oxidation method is as follows: RO (PO)_m(EO)_nH; wherein R can be alkane or alkene, PO is propylene oxide, m is more than or equal to 0, EO is ethylene oxide, and n is more than 0. The catalytic reaction formula is as follows:

disclosure of Invention

Based on the above, one of the objects of the present invention is to provide a composite catalyst, which can catalyze alcohol ether to synthesize alcohol ether carboxylate with low cost, high conversion rate and high recycling times.

The specific technical scheme is as follows:

a preparation method of the composite catalyst comprises the following steps:

(1) pretreatment of activated carbon: reacting activated carbon with an aqueous solution of an activating reagent under a heating condition to obtain pretreated activated carbon;

(2) mixing divalent palladium, divalent non-noble metal, hydrochloric acid and the obtained pretreated activated carbon, and reacting; adjusting pH to be alkaline, adding a reducing agent, reacting and separating to obtain a composite catalyst;

the activating reagent in the step (1) comprises at least one of hydrochloric acid, nitric acid and hydrogen peroxide;

the divalent non-noble metal in the step (2) comprises at least one of divalent nickel, divalent tin and divalent cobalt.

The invention also aims to provide the composite catalyst prepared by the preparation method.

The invention further aims to provide application of the composite catalyst in preparing alcohol ether carboxylate.

Still another object of the present invention is to provide a method for preparing an alcohol ether carboxylate, comprising the steps of:

(S1) mixing the alcohol ether and the composite catalyst, adjusting the pH to be alkaline by using an aqueous solution of alkali, and reacting;

(S2) the reaction solution is heated by introducing oxygen gas, and the reaction is carried out by solid-liquid separation to adjust the pH of the resulting solution to acidity.

Compared with the prior art, the invention has the following beneficial effects:

the invention firstly carries out pretreatment on the carrier activated carbon by a specific activation step, introduces functional groups on the activated carbon, promotes the dispersion of metals on the carrier and further improves the catalytic activity. In addition, the pretreated activated carbon has a mesoporous characteristic, and abundant gaps further contribute to the dispersion and loading of metal, so that the activity and the metal utilization rate of the catalyst can be further improved, and meanwhile, the stability of the composite catalyst is remarkably improved through the synergistic effect of noble metal palladium and non-noble metal. The composite catalyst prepared by the method can be recycled for a long time and keeps good catalytic activity. After the composite catalyst disclosed by the invention is subjected to catalytic reaction for 1000 hours, the high conversion rate of the alcohol ether can still be realized, and the difference between the yield of the alcohol ether carboxylate and the yield of the alcohol ether carboxylate in the first use is less than or equal to 15%. In addition, the catalytic activity of the composite catalyst is equivalent to that of a pure noble metal catalyst through the synergistic effect of the noble metal palladium and the non-noble metal, so that the cost of the catalyst is greatly reduced, and the large-scale industrial production of the catalyst is favorably realized.

Detailed Description

In order that the invention may be more readily understood, reference will now be made to the following more particular description of the invention, examples of which are set forth below. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. These embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

The embodiment provides a preparation method of a composite catalyst, which comprises the following steps:

(1) pretreatment of activated carbon: reacting activated carbon with an aqueous solution of an activating reagent under a heating condition to obtain pretreated activated carbon;

(2) mixing divalent palladium, divalent non-noble metal, hydrochloric acid and the obtained pretreated activated carbon, and reacting; adjusting pH to be alkaline, adding a reducing agent, reacting and separating to obtain a composite catalyst;

the activating reagent in the step (1) comprises at least one of hydrochloric acid, nitric acid and hydrogen peroxide;

the divalent non-noble metal in the step (2) comprises at least one of divalent nickel, divalent tin and divalent cobalt.

Specifically, the preparation method of the composite catalyst comprises the following steps:

(1) pretreatment of activated carbon: reacting activated carbon with an aqueous solution of an activating reagent under a heating condition, filtering, washing filter residues until the pH value is neutral, and drying to obtain pretreated activated carbon;

(2) mixing divalent palladium, divalent non-noble metal and hydrochloric acid, diluting with water, adding the pretreated activated carbon, stirring for reaction, adding an alkali aqueous solution to adjust the pH to be alkaline, adding a sodium borohydride aqueous solution, separating after reaction, and washing until the pH is neutral to obtain the composite catalyst.

In one embodiment, the preprocessing in step (1) comprises: mixing the activated carbon with an aqueous solution of an activating reagent, refluxing for 2-6 h at 70-100 ℃, filtering, washing and drying.

In one embodiment, the mesh number of the activated carbon is 100-300 meshes.

In one embodiment, the mass concentration of the activating reagent in the aqueous solution of the activating reagent in the step (1) is 5-20%. Preferably, the mass concentration of the activating reagent in the aqueous solution of the activating reagent in the step (1) is 8-12%.

In one embodiment, the mass-to-volume ratio of the activated carbon to the aqueous solution of the activating reagent in the step (1) is: (1-10) g (50-200) ml. Preferably, the mass-to-volume ratio of the activated carbon to the aqueous solution of the activating reagent in the step (1) is as follows: (4-6) g, (50-80) ml.

In one embodiment, the mass ratio of the divalent palladium, the divalent non-noble metal and the pretreated activated carbon in the step (2) is as follows: (2-6):(2-6):(45-55).

In one embodiment, in step (2), the adjusting the pH to basic is: adjusting pH to 8-9.

In one embodiment, the reducing agent in step (2) comprises at least one of sodium borohydride, formaldehyde, ethylene glycol, and hydrogen.

This example provides a composite catalyst prepared by the above-mentioned preparation method.

The present example provides the use of the above-described composite catalyst in the preparation of alcohol ether carboxylates.

A method for preparing an alcohol ether carboxylate, comprising the steps of:

(S1) mixing alcohol ether with the composite catalyst obtained by the preparation method, adjusting the pH to be alkaline by using an aqueous solution of alkali, and reacting;

(S2) the reaction solution is heated by introducing oxygen gas, and the reaction is carried out by solid-liquid separation to adjust the pH of the resulting solution to acidity.

In one embodiment, in the step (S1), the mass ratio of the alcohol ether to the composite catalyst is: 100:(1-20).

In one embodiment, in step (S1), the base is sodium hydroxide or potassium hydroxide.

In one embodiment, in step (S1), the pH is adjusted to 10-13; in the step (S2), the pH is adjusted to 1-2.

In one embodiment, the alcohol ether is capped with ethylene oxide.

In one embodiment, the alcohol ether has the following general structural formula: RO (PO)_m(EO)_nH; wherein R is alkyl or alkenyl; PO is epoxypropyl group, m is more than or equal to 0; EO is ethylene oxide, n > 0. The alkyl or alkenyl group contains 1 to 30 carbon atoms.

In one embodiment, the alcohol ether comprises AEO-6, AEO-7, AEO-8, AEO-9, 350, or OE-10.

The present invention will be described in further detail with reference to specific examples.