阅读说明：本技术 一种简易的还原对硝基苯酚制备对氨基苯酚的方法 (Simple method for preparing p-aminophenol by reducing p-nitrophenol ) 是由 俞伟婷 张杭 宋爽 于 2020-12-29 设计创作，主要内容包括：本发明公开了一种简易的还原对硝基苯酚制备对氨基苯酚的方法。现有的对硝基苯酚降解方法采用H-2作为温和的还原剂。但由于氢气的易燃性、高温高压反应条件以及成本高的专用设备限制了其广泛的应用。本发明的具体步骤如下：一、配置铜盐溶液,作为催化剂溶液。二、在对硝基苯酚溶液中加入含氢还原剂和催化剂溶液中进行反应,生成对氨基苯酚。本发明所需催化剂溶液配置简便,仅需简单溶解Cu(NO-3)-2·3H-2O粉末,便可以用于催化降解；处理时间短且降解效率高,仅5分钟就可以将90％以上的对硝基苯酚加氢生成对氨基苯酚；设备条件普遍,催化反应成本低,没有二次污染生成,在污水处理等领域具有潜在的应用前景。(The invention discloses a simple method for preparing p-aminophenol by reducing p-nitrophenol. The existing p-nitrophenol degradation method adopts H 2 As a mild reducing agent. But its wide use is limited by the flammability of hydrogen, high temperature and pressure reaction conditions, and the high cost of specialized equipment. The method comprises the following specific steps: firstly, preparing a copper salt solution as a catalyst solution. Secondly, adding a hydrogen-containing reducing agent and a catalyst solution into the p-nitrophenol solution for reaction to generate the p-aminophenol. The catalyst solution needed by the invention is simple and convenient to prepare, and only Cu (NO) needs to be simply dissolved 3 ) 2 ·3H 2 O powder, which can be used for catalytic degradation; short treatment time and high degradation efficiency, and more than 90 percent of p-nitrophenol can be hydrogenated into p-aminobenzene in only 5 minutesPhenol; the method has the advantages of common equipment conditions, low catalytic reaction cost, no secondary pollution generation and potential application prospect in the fields of sewage treatment and the like.)

1. A simple method for preparing p-aminophenol by reducing p-nitrophenol is characterized by comprising the following steps: step one, preparing a copper salt solution as a catalyst solution;

and step two, adding a hydrogen-containing reducing agent and a catalyst solution into the p-nitrophenol solution for reaction to generate the p-aminophenol.

2. The method for preparing p-aminophenol by simply reducing p-nitrophenol according to claim 1, wherein: the copper salt solution is Cu (NO)₃)₂And (3) solution.

3. The method for preparing p-aminophenol by simply reducing p-nitrophenol according to claim 1, wherein: the hydrogen-containing reducing agent is sodium borohydride.

4. The method for preparing p-aminophenol by simply reducing p-nitrophenol according to claim 1, wherein: the copper salt solution is passed through Cu (NO)₃)₂·3H₂And (4) preparing O powder.

5. The method for preparing p-aminophenol by simply reducing p-nitrophenol according to claim 1, wherein: in the second step, the molar concentration of copper ions in the mixed solution of the p-nitrophenol solution, the hydrogen-containing reducing agent and the catalyst solution is 3.7 multiplied by 10^-7～3.7×10^-6mol·L^-1。

6. The method for preparing p-aminophenol by simply reducing p-nitrophenol according to claim 1, wherein: the reaction temperature in step two was 25 ℃.

Technical Field

The invention belongs to the technical field of treatment of p-nitrophenol waste materials, and relates to a method for preparing p-aminophenol by reducing p-nitrophenol by using sodium borohydride as a reducing agent and a copper nitrate solution as a catalyst.

Background

P-nitrophenol is a common organic chemical raw material and is mainly applied to synthesis of fine chemicals such as pesticides, resins, medicines, dyes and the like. With the increasing demand at home and abroad, p-nitrophenol is widely synthesized and used, so that the p-nitrophenol is increasingly accumulated in the ecological environment. Due to its high toxicity and relatively difficult degradability, p-nitrophenol has been included as one of the 129 preferred pollutants in the U.S. environmental protection agency (USEPA) aqueous environment. Therefore, the research on a simple, convenient, rapid and effective degradation method is of great significance. Meanwhile, the p-aminophenol is used as a product after the p-nitrophenol is hydrogenated, so that the harm to the environment is obviously reduced. And the p-aminophenol can be used for producing important chemical medicines such as paracetamol and paracetamol, and products such as an antioxidant, a developer, a petroleum additive and the like.

There are many ways of converting p-nitrophenol to p-aminophenol, among which H₂Have been proposed by many researchers as mild reducing agents. But its wide use is limited by the flammability of hydrogen, high temperature and pressure reaction conditions, and the high cost of specialized equipment. In contrast, the method which takes sodium borohydride as a reducing agent and is carried out in an aqueous medium under mild conditions is relatively simple and has low pollution. Various noble metals such as Ag, Ru, Au, Pd and Pt show good catalytic activity in the catalytic reduction of p-nitrophenol using sodium borohydride. However, the high cost and scarcity of noble metals limits their large-scale application, and researchers in the relevant field are actively exploring non-noble metal-based catalysts to reduce catalyst costs, such as metals like Fe, Mg, Co, Cu, etc. However, finding a suitable catalyst to further optimize the degradation pathway of p-nitrophenol remains a challenge.

Disclosure of Invention

In view of the above technical problems in the prior art, the present invention aims to provide a simple method for preparing p-aminophenol by reducing p-nitrophenol.

The method comprises the following specific steps:

step one, preparing a copper salt solution as a catalyst solution.

And step two, adding a hydrogen-containing reducing agent and a catalyst solution into the p-nitrophenol solution for reaction to generate the p-aminophenol.

Preferably, the copper salt solution is Cu (NO)₃)₂And (3) solution.

Preferably, the hydrogen-containing reducing agent is sodium borohydride.

Preferably, the copper salt solution is prepared by passing Cu (NO)₃)₂·3H₂And (4) preparing O powder.

Preferably, in the second step, the molar concentration of copper ions in the mixed solution of the p-nitrophenol solution, the hydrogen-containing reducing agent and the catalyst solution is 3.7X 10^-7～3.7×10^-6mol·L^-1。

Preferably, the reaction temperature in step two is 25 ℃.

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

the catalyst solution needed by the invention is simple and convenient to prepare, and only Cu (NO) needs to be simply dissolved₃)₂·3H₂O powder, which can be used for catalytic degradation; the treatment time is short, the degradation efficiency is high, and more than 90 percent of p-nitrophenol can be hydrogenated to generate p-aminophenol in only 5 minutes; the method has the advantages of common equipment conditions, low catalytic reaction cost, no secondary pollution generation and potential application prospect in the fields of sewage treatment and the like.

Drawings

FIG. 1 is a graph showing the comparison of the degradation efficiency of p-nitrophenol in example 1 of the present invention and comparative examples 1 to 3;

FIG. 2 is a graph showing the comparison of the degradation efficiency of p-nitrophenol in examples 1 to 3 of the present invention;

FIG. 3 is a graph showing the change in the concentration of p-nitrophenol and p-aminophenol in example 1 of the present invention.

Detailed Description

The present invention is further illustrated by the following examples, which should not be construed as limiting the scope of the invention.

Example 1

A simple method for preparing p-aminophenol by reducing p-nitrophenol comprises the following specific steps

Preparing a required catalyst solution: 14.5mg of Cu (NO) are weighed out₃)₂·3H₂O powder, which was dissolved in 300mL of deionized water under sonication.

The prepared catalyst solution is used as a catalyst, sodium borohydride is used for catalyzing and reducing p-nitrophenol, and the process is as follows:

2mL of a p-nitrophenol solution (3.5 mmol. L) was prepared^-1) The mixture was added to a beaker containing 54mL of deionized water, and 53.2mg of sodium borohydride was added and dissolved by stirring. The beaker is placed in a constant temperature water bath, and 100uL of the catalyst solution is added for reaction (25 ℃). And during the reaction, the solution in the beaker is sampled every 1min, and the concentration of the nitrophenol is detected by an ultraviolet spectrophotometer, and the result is shown in figure 1.

In this example, the molar concentration of copper ions in the reaction system was 3.7X 10^-7mol·L^-1. Through experiments, the molar concentration of copper ions in the reaction system is adjusted to 3.7 multiplied by 10^-6mol·L^-1In this case, the catalyst can have a more excellent catalytic effect.

Comparative example 1

Preparing a required catalyst solution, comprising the following steps: 24.2mg Fe (NO) are weighed out₃)₃·9H₂O powder, which was dissolved in 300mL of deionized water under sonication.

The prepared catalyst solution is used as a catalyst, sodium borohydride is used for catalyzing and reducing p-nitrophenol, and the process is as follows:

2mL of a p-nitrophenol solution (3.5 mmol. L) was prepared^-1) The mixture was added to a beaker containing 54mL of deionized water, and 53.2mg of sodium borohydride was added and dissolved by stirring. The beaker is placed in a constant temperature water bath, and 100uL of the catalyst solution is added for reaction (25 ℃). And during the reaction, the solution in the beaker is sampled every 1min, and the concentration of the nitrophenol is detected by an ultraviolet spectrophotometer, and the result is shown in figure 1.

Comparative example 2

Preparing a required catalyst solution, comprising the following steps: weighing 17.9mg Zn(NO₃)₂·6H₂O powder, which was dissolved in 300mL of deionized water under sonication.

The prepared catalyst solution is used as a catalyst, sodium borohydride is used for catalyzing and reducing p-nitrophenol, and the process is as follows:

2mL of a p-nitrophenol solution (3.5 mmol. L) was prepared^-1) The mixture was added to a beaker containing 54mL of deionized water, and 53.2mg of sodium borohydride was added and dissolved by stirring. The beaker is placed in a constant temperature water bath, and 100uL of the catalyst solution is added for reaction (25 ℃). And during the reaction, the solution in the beaker is sampled every 1min, and the concentration of the nitrophenol is detected by an ultraviolet spectrophotometer, and the result is shown in figure 1.

Comparative example 3

Preparing a required catalyst solution, comprising the following steps: weighing 17.5mg Ni (NO)₃)₂·6H₂O powder, which was dissolved in 300mL of deionized water under sonication.

The prepared catalyst solution is used as a catalyst, sodium borohydride is used for catalyzing and reducing p-nitrophenol, and the process is as follows:

2mL of a p-nitrophenol solution (3.5 mmol. L) was prepared^-1) The mixture was added to a beaker containing 54mL of deionized water, and 53.2mg of sodium borohydride was added and dissolved by stirring. The beaker is placed in a constant temperature water bath, and 100uL of the catalyst solution is added for reaction (25 ℃). And during the reaction, the solution in the beaker is sampled every 1min, and the concentration of the nitrophenol is detected by an ultraviolet spectrophotometer, and the result is shown in figure 1.

Comparative example 4

Preparing a required catalyst solution, comprising the following steps: 17.5mg Fe (NO) are weighed out₃)₃·9H₂O powder, which was dissolved in 300mL of deionized water under sonication.

The prepared catalyst solution is used as a catalyst, sodium borohydride is used for catalyzing and reducing p-nitrophenol, and the process is as follows:

2mL of a p-nitrophenol solution (3.5 mmol. L) was prepared^-1) AddingPut into a beaker filled with 54mL of deionized water, and then 53.2mg of sodium borohydride is added, stirred and dissolved uniformly. The beaker is placed in a constant temperature water bath, and 100uL of the catalyst solution is added for reaction (25 ℃). And during the reaction, the solution in the beaker is sampled every 1min, and the concentration of the nitrophenol is detected by an ultraviolet spectrophotometer, and the result is shown in figure 1.

The comparison between the effect of example 1 and the effect of comparative examples 1 to 4 on degrading p-nitrophenol is shown in fig. 1, and it can be seen from the figure that in the case of sodium borohydride/p-aminophenol 200: 1, PNP concentration 0.13 mmol. L^-1Under the conditions, the metal nitrates such as cobalt nitrate, zinc nitrate, nickel nitrate, and ferric nitrate used as the control group have little catalytic effect on the degradation of p-nitrophenol, and the p-nitrophenol cannot be reduced and hydrogenated to produce p-aminophenol. In the embodiment 1, the catalytic reduction is performed by using the copper nitrate solution, so that the catalytic reaction can be effectively performed, and the p-nitrophenol is reduced and hydrogenated to prepare the p-aminophenol.

Example 2

Preparing a required catalyst solution, comprising the following steps: weighing 15mg of CuSO₄·5H₂O powder, which was dissolved in 300mL of deionized water under sonication.

The prepared catalyst solution is used as a catalyst, sodium borohydride is used for catalyzing and reducing p-nitrophenol, and the process is as follows:

2mL of a p-nitrophenol solution (3.5 mmol. L) was prepared^-1) The mixture was added to a beaker containing 54mL of deionized water, and 53.2mg of sodium borohydride was added and dissolved by stirring. The beaker is placed in a constant temperature water bath, and 100uL of the catalyst solution is added for reaction (25 ℃). And while the reaction was in progress, the solution in the beaker was sampled every 1min, and the concentration of nitrophenol was measured by an ultraviolet spectrophotometer, the results of which are shown in FIG. 2.

Example 3

Preparing a required catalyst solution, comprising the following steps: 10.2mg of CuCl are weighed out₂·2H₂O powder, which was dissolved in 300mL of deionized water under sonication.

The prepared catalyst solution is used as a catalyst, sodium borohydride is used for catalyzing and reducing p-nitrophenol, and the process is as follows:

2mL of a p-nitrophenol solution (3.5 mmol. L) was prepared^-1) The mixture was added to a beaker containing 54mL of deionized water, and 53.2mg of sodium borohydride was added and dissolved by stirring. The beaker is placed in a constant temperature water bath, and 100uL of the catalyst solution is added for reaction (25 ℃). And while the reaction was in progress, the solution in the beaker was sampled every 1min, and the concentration of nitrophenol was measured by an ultraviolet spectrophotometer, the results of which are shown in FIG. 2.

The comparative situation of the degradation effect of p-nitrophenol in the examples 1-3 is shown in fig. 2, and it can be seen that the copper sulfate and the copper chloride solution can also play a role in the degradation catalysis of p-nitrophenol, but compared with the copper nitrate solution, the copper nitrate solution has a significantly better catalysis effect.

The concentration changes of p-aminophenol and p-nitrophenol in the detection process of example 1 were detected by High Performance Liquid Chromatography (HPLC), and it can be seen that p-nitrophenol was rapidly converted into p-aminophenol within 5 minutes, and the conversion rate reached 90% or more after 5 minutes.

In conclusion, the method for preparing p-aminophenol by degrading p-nitrophenol, which is disclosed by the invention, has the advantages that the needed catalyst solution is simple and convenient to prepare, and only Cu (NO) needs to be simply dissolved₃)₂·3H₂O powder, which can be used for catalytic degradation; the treatment time is short, the degradation efficiency is high, and more than 90 percent of p-nitrophenol can be hydrogenated to generate p-aminophenol in only 5 minutes; the method has the advantages of common equipment conditions, low catalytic reaction cost, no secondary pollution generation and potential application prospect in the fields of sewage treatment and the like.