CN118086927A

CN118086927A - Alkane oxidation method and reaction device

Info

Publication number: CN118086927A
Application number: CN202410082559.7A
Authority: CN
Inventors: 陆奇; 刘文萱; 徐冰君
Original assignee: Tsinghua University; Peking University
Current assignee: Tsinghua University; Peking University
Priority date: 2024-01-19
Filing date: 2024-01-19
Publication date: 2024-05-28
Anticipated expiration: 2044-01-19
Also published as: CN118086927B; WO2025152332A1

Abstract

The present invention relates to the field of chemical technology, and in particular to an alkane oxidation method and a reaction device, the method comprising: providing an electrolytic cell, the electrolytic cell being filled with an electrolyte, and a first electrode and a second electrode arranged in the electrolyte, the electrolyte containing an acidic material, the material of the first electrode comprising copper, the material of the second electrode comprising copper, applying voltage to the first electrode and the second electrode, and introducing an alkane and an oxidant into the electrolyte to oxidize the alkane. The present application can prepare high value-added chemicals by activating alkanes at normal temperature and pressure, and has the characteristics of low cost and simple method.

Description

Oxidation method of alkane and reaction device

Technical Field

The invention relates to the technical field of chemical industry, in particular to an oxidation method and a reaction device of alkane.

Background

The method for directly activating hydrocarbon alkane to convert hydrocarbon alkane into alkene, alkyne, oxygen-containing derivative and other high-added-value chemical products has important economic value. However, due to the influence of factors such as poor polarity of carbon-hydrogen bonds and high bond energy, equipment with high energy consumption and high carbon emission is generally required to provide high-temperature and high-pressure extreme reaction conditions to realize the process. In addition, the provision of an externally applied potential is also a way of changing the energy of the system, and the reaction conditions are milder and the production cost is lower, but the conversion of alkane into high value-added chemicals in the prior art adopts noble metal as a working electrode, so that the cost is extremely high and the conversion needs to be carried out at high temperature and high pressure. Therefore, developing a high-performance and stable catalyst and a corresponding reaction system to realize high-value-added chemical products by high-efficiency electrochemical activation of alkane synthesis under normal temperature and pressure conditions still faces a plurality of problems and challenges.

Disclosure of Invention

In view of the above, an embodiment of the present application provides a method and apparatus for oxidizing an alkane, which can react at normal temperature and normal pressure at low cost.

In a first aspect, the present application provides a process for the oxidation of an alkane comprising:

Providing an electrolytic cell, wherein the electrolytic cell is filled with electrolyte, and a first electrode and a second electrode which are arranged in the electrolyte, the electrolyte contains acidic materials, the material of the first electrode comprises copper, and the material of the second electrode comprises copper;

and applying voltage to the first electrode or the second electrode, and introducing alkane and oxidant into the electrolyte to oxidize the alkane.

In some embodiments, the acidic material comprises at least one of sulfuric acid, perchloric acid, phosphoric acid, hydrochloric acid, hydrobromic acid, and hydroiodic acid.

In some embodiments, the concentration of hydrogen ions in the electrolyte is 1X 10 ^-7 mol/L to 2.0mol/L.

In some embodiments, the electrolyte further comprises a copper salt.

In some embodiments, the copper salt comprises at least one of Cu (ClO ₄)₂、CuSO₄ and CuCl ₂).

In some embodiments, the molar concentration of the copper salt in the electrolyte is 0.05mol/L to 0.8mol/L.

In some embodiments, the alkane comprises at least one of a chain alkane and a cyclic alkane.

In some embodiments, the product after oxidation of the alkane comprises at least one of an alkene, alkyne, alcohol, carboxylic acid, ketone, aldehyde, ester, phenol, and ether.

In some embodiments, the oxidizing agent comprises at least one of an organic peroxide, ozone, hydrogen peroxide, oxygen, and air.

In some embodiments, the volume ratio of the oxidizing agent is 5% -50% based on 100% of the total volume of the alkane and the oxidizing agent.

In some embodiments, the voltage applied in the method is a constant voltage.

In some embodiments, the voltage applied in the method is 0.4v to 1.4v.

In some embodiments, the temperature of oxidation in the method is 10 ℃ to 40 ℃ and the pressure is 0.5atm to 1.5atm.

In a second aspect, the present application provides a reaction apparatus for carrying out the oxidation process of an alkane as described in the first aspect, the reaction apparatus comprising:

The electrolytic cell comprises a shell, a first electrode and a second electrode, wherein the first electrode and the second electrode are arranged in the shell, electrolyte is filled in the shell, the shell is further provided with a gas inlet and a gas outlet, and the gas inlet is used for introducing alkane; the first electrode and the second electrode are inserted into the electrolyte respectively.

In some embodiments, the electrolytic cell is divided into a first chamber and a second chamber, the first electrode disposed within the first chamber and the second electrode disposed within the second chamber;

The gas inlet comprises a first gas inlet and a second gas inlet, the first gas inlet is arranged on the first chamber, and the second gas inlet is arranged on the second chamber;

The gas outlet comprises a first gas outlet and a second gas outlet, the first gas outlet is arranged on the first chamber, and the second gas outlet is arranged on the second chamber;

and a separation membrane is arranged between the first chamber and the second chamber.

Compared with the prior art, the application has at least the following beneficial effects:

The application adopts an electrochemical method to oxidize alkane to prepare high added value chemicals, the first electrode and the second electrode both comprise copper, copper is used as a catalyst, and a large number of active sites can be formed by combining an oxidant and an acid solution at normal temperature and normal pressure, so that the alkane activation reaction under mild conditions can be realized, and the first electrode is dissolved along with the copper electrode in the process of electrochemically activating alkane; copper ions dissolved in the electrolyte are simultaneously deposited on the second electrode, so that the copper catalyst is stably and efficiently recycled, the process of preparing high-added-value chemical products by electrochemically activating alkane for a long time with high performance is realized, and copper materials are cheap and easy to obtain. Therefore, the application has the advantages of simple method, low cost, easy scale and the like.

Drawings

FIG. 1 is a schematic structural view of a reaction apparatus provided in example 1 of the present application.

Fig. 2 is a schematic structural view of a reaction apparatus provided in example 20 of the present application.

FIG. 3 is a graph comparing test results of examples 1-6 of the present application.

FIG. 4 is a graph showing the comparison of the test results of example 1, comparative example 1 and examples 7 to 9.

FIG. 5 is a graph showing the comparison of the test results of examples 1, 2 and 10-14.

FIG. 6 is a graph showing the comparison of the test results of example 1 and examples 15 to 19.

FIG. 7 is a graph showing the test results of the reaction for 10h in example 20 of the present application.

Wherein, 10-shell; 11-a first chamber; 12-a second chamber; 20-a first electrode; 30-a second electrode; 40-gas inlet; 41-a first gas inlet; 42-a second gas inlet; 50-gas outlet; 51-a first gas outlet; 52-a second gas outlet; 60-a reference electrode; 61-a first reference electrode; 62-a second reference electrode; 70-isolating film.

Detailed Description

The present application will be described in further detail with reference to embodiments and examples. These embodiments and examples are provided only to illustrate the present application and are not intended to limit the scope of the present application in order that the present disclosure may be more thorough and complete. It will also be appreciated that the present application may be embodied in many different forms and is not limited to the embodiments and examples described herein, but may be modified or altered by persons skilled in the art without departing from the spirit of the application, and equivalents thereof are also intended to fall within the scope of the application. Furthermore, in the following description, numerous specific details are set forth in order to provide a more thorough understanding of the application, it being understood that the application may be practiced without one or more of these details.

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 application belongs. The terminology used herein in the description of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

In the present application, "optional" means optional or not, that is, means any one selected from two parallel schemes of "with" or "without". If multiple "alternatives" occur in a technical solution, if no particular description exists and there is no contradiction or mutual constraint, then each "alternative" is independent.

In the present application, the terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or quantity, nor as implying an importance or quantity of a technical feature being indicated. Moreover, "first," "second," etc. are for non-exhaustive list description purposes only, and it should be understood that no closed limitation on the number is made.

In the application, the technical characteristics described in an open mode comprise a closed technical scheme composed of the listed characteristics and also comprise an open technical scheme comprising the listed characteristics.

In the present application, a numerical range (i.e., a numerical range) is referred to, and, unless otherwise indicated, a distribution of optional values within the numerical range is considered to be continuous and includes two numerical endpoints (i.e., a minimum value and a maximum value) of the numerical range, and each numerical value between the two numerical endpoints. When a numerical range merely points to integers within the numerical range, unless expressly stated otherwise, both endpoints of the numerical range are inclusive of the integer between the two endpoints, and each integer between the two endpoints is equivalent to the integer directly recited. When multiple numerical ranges are provided to describe a feature or characteristic, the numerical ranges may be combined. In other words, unless otherwise indicated, the numerical ranges disclosed in this application are to be understood to include any and all subranges subsumed therein. The "numerical value" in the numerical interval may be any quantitative value, such as a number, a percentage, a proportion, or the like. "numerical interval" allows to broadly include quantitative intervals such as percentage intervals, proportion intervals, ratio intervals, etc.

All documents mentioned in this disclosure are incorporated by reference in this disclosure as if each were individually incorporated by reference. Unless otherwise indicated to the contrary by the intent and/or technical aspects of the present application, all references to which this application pertains are incorporated by reference in their entirety for all purposes. When reference is made to a cited document in the present application, the definitions of the relevant technical features, terms, nouns, phrases, etc. in the cited document are also incorporated. In the case of the cited documents, examples and preferred modes of the cited relevant technical features are also incorporated into the present application by reference, but are not limited to being able to implement the present application. It should be understood that when a reference is made to the description of the application in conflict with the description, the application is modified in light of or adaptive to the description of the application.

In the traditional technology, high-value-added chemical products such as alkane direct conversion into alkene, oxygen-containing derivatives and the like generally need high temperature (200 ℃ -600 ℃) or high pressure (5 bar-50 bar), and the reaction process is high in energy consumption and high in carbon emission. In addition, the traditional electrochemical activation alkane technology generally uses a noble metal catalyst, the preparation process is complex, the cost is high, the catalyst is easy to deactivate under the reaction condition, the excessive oxidation problem of the product is serious, and the large-scale production requirement is difficult to meet. The copper-containing electrode is adopted as the first electrode and the second electrode, the raw materials are cheap and easy to obtain, the reactivity and the selectivity are high, the amplification is easy, the electrochemical activation of alkane at normal temperature and normal pressure is realized to prepare high-added-value chemical products, and the use of high-temperature and high-pressure equipment is avoided.

In a first aspect, the application provides a process for the oxidation of an alkane comprising:

The application adopts an electrochemical method to oxidize alkane to prepare high added value chemicals, the first electrode and the second electrode both comprise copper, copper is used as a catalyst, and a large number of active sites can be formed by combining oxygen and an acidic solution at normal temperature and normal pressure, so that alkane activation reaction under mild conditions can be realized, and the first electrode is dissolved along with the copper electrode in the process of electrochemically activating alkane; copper ions dissolved in the electrolyte are simultaneously deposited on the second electrode, so that the copper catalyst is stably and efficiently recycled, the process of preparing high-added-value chemical products by electrochemically activating alkane for a long time with high performance is realized, and copper materials are cheap and easy to obtain. Therefore, the application has the advantages of simple method, low cost, easy scale and the like.

It is understood that when a voltage is applied to the first electrode, the first electrode is a working electrode, and the second electrode is a counter electrode; when a voltage is applied to the second electrode, the first electrode is a counter electrode, and the second electrode is a working electrode.

It will be appreciated that the present application produces high value-added chemicals by oxidation of alkanes.

In some embodiments, the concentration of hydrogen ions in the electrolyte is 1X 10 ^-7 mol/L to 2.0mol/L. Preferably, the concentration of hydrogen ions is 1.0mol/L to 2.0mol/L, and the oxidation performance of alkane is optimal under the condition.

In some embodiments, the electrolyte further comprises a copper salt.

In some embodiments, the molar concentration of the copper salt in the electrolyte is 0.05mol/L to 0.8mol/L, for example, 0.05mol/L, 0.1mol/L, 0.2mol/L, 0.3mol/L, 0.4mol/L, 0.5mol/L, 0.6mol/L, 0.7mol/L, or 0.8mol/L.

The application controls the molar concentration of copper salt, and can realize excellent alkane oxidation performance and inhibit the consumption of a large amount of hydrogen ions. If the molar concentration of copper salts is relatively low, severe consumption of hydrogen ions may occur, resulting in a large amount of acidic solution being wasted, affecting the oxidation of alkanes; if the molar concentration of copper salt is relatively high, the oxidation properties of the alkane may be reduced. The molar concentration of the copper salt is preferably 0.2mol/L to 0.4mol/L, so that the excellent alkane oxidation performance can be realized, and meanwhile, the consumption of hydrogen ions is very small (< 0.1 mol/L).

In some embodiments, the alkane comprises at least one of a chain alkane and a cyclic alkane. For example, the alkane is selected from the group consisting of a lower alkane having 1 to 4 carbon atoms, a higher alkane having 5 to 20 carbon atoms, and a cycloalkane having 3 to 20 carbon atoms.

In some embodiments, the product after oxidation of the alkane comprises at least one of alkene, alkyne, alcohol, carboxylic acid, ketone, aldehyde, ester, phenol, and ether.

In some embodiments, the oxidant is present in a volume ratio of 5% -50%, such as 5%, 10%, 15%, 20%, 22%, 24%, 26%, 28%, 30%, 32%, 34%, 36%, 38%, 40%, 42%, 44%, 46%, 48% or 50%, based on 100% total volume of the alkane and the oxidant.

In some embodiments, the voltage applied in the method is a constant voltage.

In some embodiments, the voltage applied in the method is 0.4V-1.4V, which may be, for example, 0.4V, 0.5V, 0.6V, 0.7V, 0.8V, 0.9V, 1.0V, 1.1V, 1.2V, 1.3V, or 1.4V. The voltage applied in the present application refers to a voltage relative to a standard hydrogen electrode.

The application can control the applied voltage in the electrolysis process and effectively regulate and control the activation performance of alkane. If the voltage is relatively low, there may be poor alkane activation activity; if the voltage is relatively high, the copper dissolution rate may be too high, the stability of the electrolytic cell is affected, and long-time operation of the electrolytic cell cannot be ensured.

In some embodiments, the temperature of oxidation in the method is 10 ℃ to 40 ℃, which may be, for example, 10 ℃, 12 ℃, 14 ℃, 16 ℃, 18 ℃,20 ℃, 22 ℃, 24 ℃, 26 ℃, 28 ℃,30 ℃, 32 ℃, 34 ℃, 36 ℃, 38 ℃, or 40 ℃.

In some embodiments, the pressure of oxidation in the method is 0.5atm to 1.5atm, and may be, for example, 0.5atm, 0.6atm, 0.7atm, 0.8atm, 0.9atm, 1.0atm, 1.1atm, 1.2atm, 1.3atm, 1.4atm, or 1.5atm.

In some embodiments, the reacted cell stops flowing alkane and oxidant, instead of flowing inert gas, and the direction of current is changed so that copper deposited on the second electrode dissolves into the electrolyte and deposits to form copper on the first electrode. According to the application, the current direction is changed and inert gas is introduced, so that the regeneration of the first electrode is realized, and the recycling is realized.

It is understood that inert gas in the present application means a gas which does not participate in the reaction during the electrochemical reaction, and may be, for example, at least one of argon and nitrogen.

In some embodiments, during the reaction, the electrolyte is stirred; optionally, the stirring speed is 1000 rpm-2000 rpm.

In some embodiments, the reaction device further comprises a reference electrode inserted into the electrolyte. It will be appreciated that the reference electrode is an electrode designed to have a specific potential and that a reference point of known potential is provided during the electrochemical reaction for determining the potential of the first electrode. Typically the reference electrode does not participate in the reaction, for example the reference electrode may be a mercury/mercurous sulphate electrode.

And a separation membrane is arranged between the first chamber and the second chamber. Alternatively, the separator is used to conduct ions and block oxygen, and may be a perfluorosulfonic acid resin separator, for example.

Illustratively, there is provided a method for oxidation of an alkane by a reaction device having an electrolytic cell divided into a first chamber and a second chamber, comprising:

Introducing alkane and oxidant into the first chamber through the first gas inlet, and applying a voltage to a first electrode in the first chamber; introducing inert gas into the second chamber through the second gas inlet, dissolving copper ions into the electrolyte by the first electrode in the first chamber in the reaction process, simultaneously depositing the copper ions dissolved into the electrolyte on the second electrode, simultaneously carrying out electrochemical catalytic activation reaction on alkane and oxidant on the surface of the first electrode, dehydrogenating and oxidizing the alkane, outputting gaseous high-value additional chemicals through the first gas outlet, and forming liquid high-value additional chemicals in the electrolyte;

Stopping introducing alkane and oxidant into the first gas inlet, and stopping applying voltage to the first electrode in the first chamber instead of introducing inert gas; simultaneously stopping introducing inert gas into the second gas inlet, replacing the inert gas with alkane and oxidant, and applying voltage to a second electrode in the second chamber; electrochemical catalytic activity reaction of alkane occurs in the second chamber, and copper deposition is carried out on the first electrode in the first chamber;

The above steps are alternately performed.

According to the application, through the reaction device with the double-chamber structure, electrochemical catalytic reaction and electrodeposition regeneration are alternately carried out through the two chambers, so that continuous preparation of alkane converted into high-added-value chemicals is realized.

It will be appreciated that the oxide layer on the electrode surface is removed by polishing before the first and second electrodes are used, avoiding the presence of the oxide layer affecting the use of the electrodes.

Embodiments of the present invention will be described in detail below with reference to examples. It is to be understood that these examples are illustrative of the present invention and are not intended to limit the scope of the present invention. The experimental methods in the following examples, in which specific conditions are not noted, are preferably referred to the guidelines given in the present invention, and may be according to the experimental manual or conventional conditions in the art, the conditions suggested by the manufacturer, or the experimental methods known in the art.

Example 1

The embodiment provides a reaction device, as shown in fig. 1, comprising an electrolytic cell, a first electrode and a second electrode, wherein the electrolytic cell comprises a shell 10 filled with electrolyte, a gas inlet 40 and a gas outlet 50 are formed on the shell 10, the first electrode 20 and the second electrode 30 are respectively inserted into the electrolyte, the first electrode 20 and the second electrode 30 are both made of pure copper, the length x width x height is 2cm x 0.5mm, the concentration of HClO ₄ in the electrolyte is 1mol/L, the concentration of Cu (ClO ₄)₂ is 0.2mol/L, and the reaction device further comprises a reference electrode 60, the reference electrode 60 is inserted between the first electrode 20 and the second electrode 30, and the reference electrode 60 is a mercury/mercurous sulfate electrode.

The preparation of high value-added chemicals using ethane and oxygen using the above reaction apparatus includes:

the first electrode 20 and the second electrode 30 are polished respectively, and the polishing process includes: firstly, polishing for 5min by using 800-mesh sand paper, then polishing for 5min by using 1500-mesh sand paper, finally, cleaning a copper sheet by using deionized water, and repeating the steps for 3 times to finish polishing treatment of the first electrode 20 and the second electrode 30;

Reinserting the first electrode 20 and the second electrode 30 into the electrolytic cell, introducing ethane and oxygen into the gas inlet 40 at a flow rate of 15mL/min, wherein the oxygen accounts for 20% of the total volume of the mixed gas of ethane and oxygen, applying a voltage of 1V (vs. she) to the first electrode 20, stirring the electrolyte at 1500rpm during the reaction, reacting at 25 ℃ under a reaction pressure of 1atm for 30min, obtaining a gaseous product at the gas outlet 50, and obtaining a liquid product in the electrolyte.

Example 2

High value chemicals were prepared using ethane and oxygen in the same manner as in example 1, except that the voltage applied to the first electrode was 0.4V (vs.

Example 3

High value chemicals were prepared using ethane and oxygen in the same manner as in example 1, except that the voltage applied to the first electrode was 0.6V (vs.

Example 4

High value chemicals were prepared using ethane and oxygen in the same manner as in example 1, except that the voltage applied to the first electrode was 0.8V (vs.

Example 5

High value chemicals were prepared using ethane and oxygen in the same manner as in example 1, except that the voltage applied to the first electrode was 1.2V (vs.

Example 6

High value chemicals were prepared using ethane and oxygen in the same manner as in example 1, except that the voltage applied to the first electrode was 1.4V (vs.

Example 7

A high value-added chemical was prepared using ethane and oxygen in the same manner as in example 1 except that the concentration of HClO ₄ in the electrolyte was 0.1mol/L.

Example 8

A high value-added chemical was prepared using ethane and oxygen in the same manner as in example 1 except that the concentration of HClO ₄ in the electrolyte was 0.5mol/L.

Example 9

A high value-added chemical was prepared using ethane and oxygen in the same manner as in example 1 except that the concentration of HClO ₄ in the electrolyte was 2.0mol/L.

Example 10

The high value chemicals were prepared using ethane and oxygen in the manner of example 1, except that oxygen was 5% of the total volume of ethane and oxygen.

Example 11

The high value chemicals were prepared using ethane and oxygen in the manner of example 1, except that oxygen was 10% of the total volume of ethane and oxygen.

Example 12

The high value chemicals were prepared using ethane and oxygen in the manner of example 1, except that oxygen was 30% of the total volume of ethane and oxygen.

Example 13

The high value chemicals were prepared using ethane and oxygen in the manner of example 1, except that the oxygen was 40% of the total volume of ethane and oxygen.

Example 14

The high value chemicals were prepared using ethane and oxygen in the manner of example 1, except that the oxygen was 50% of the total volume of ethane and oxygen.

Example 15

A high value-added chemical was prepared using ethane and oxygen in the same manner as in example 1, except that Cu (ClO ₄)₂ concentration of 0.1 mol/L) was used in the electrolyte.

Example 16

A high value-added chemical was prepared using ethane and oxygen in the same manner as in example 1, except that Cu (ClO ₄)₂ concentration of 0.4 mol/L) was used in the electrolyte.

Example 17

A high value-added chemical was prepared using ethane and oxygen in the same manner as in example 1, except that Cu (ClO ₄)₂ concentration of 0.6 mol/L) was used in the electrolyte.

Example 18

A high value-added chemical was prepared using ethane and oxygen in the same manner as in example 1, except that Cu (ClO ₄)₂ concentration of 0.8 mol/L) was used in the electrolyte.

Example 19

A high value-added chemical was prepared using ethane and oxygen in the same manner as in example 1 except that Cu (ClO ₄)₂, i.e., cu (ClO ₄)₂ concentration of 0 mol/L) was not added to the electrolyte.

Example 20

The present embodiment provides a reaction apparatus, as shown in fig. 2, comprising an electrolytic cell, a first electrode 20 and a second electrode 30, the electrolytic cell comprising a housing 10 filled with an electrolyte, a first chamber 11 and a second chamber 12 being divided into the housing, the first chamber 11 being provided with a first gas inlet 41 and a first gas outlet 51, and a first reference electrode 61 being further provided in the first chamber 11; the second chamber 12 is provided with a second gas inlet 42 and a second gas outlet 52, and a second reference electrode 62 is also provided within the second chamber 12; the first electrode 20 is disposed in the first chamber 11, and the second electrode 30 is disposed in the second chamber 12; the first chamber 11 and the second chamber 12 are partitioned by a partition film 70, and the partition film 70 is a perfluorosulfonic acid resin membrane.

Wherein, the first electrode 20 and the second electrode 30 are both pure copper, the length, width and height dimensions are 2cm×2cm×0.5mm, the concentration of HClO ₄ in the electrolyte is 1mol/L, the concentration of Cu (ClO ₄)₂ is 0.2mol/L, and the first reference electrode 61 and the second reference electrode 62 are both mercury/mercurous sulfate electrodes.

Reinserting the first electrode 20 and the second electrode 30 into the electrolytic cell, introducing ethane and oxygen into the first gas inlet 41 at a flow rate of 15mL/min, wherein the oxygen accounts for 20% of the total volume of the mixed gas of ethane and oxygen, and applying a voltage of 1V (vs. she) to the first electrode 20; introducing 15mL/min nitrogen into the second gas inlet 42, stirring the electrolyte at 1500rpm during the reaction, wherein the reaction temperature is 25 ℃, the reaction pressure is 1atm, and after 20min of reaction, obtaining a gaseous product at the first gas outlet 51 and a liquid product in the electrolyte of the first chamber 11;

Replacing the gas introduced into the first gas inlet 41 with 15mL/min nitrogen, and stopping applying the voltage to the first electrode 20; the second gas inlet 42 is filled with gas replaced by ethane and oxygen at a flow rate of 15mL/min, oxygen accounts for 20% of the total volume of the mixed gas of ethane and oxygen, and a voltage of 1V (vs. she) is applied to the second electrode 30; during the reaction, the electrolyte was stirred at 1500rpm at 25℃under a reaction pressure of 1atm for 20 minutes to obtain a gaseous product at the second gas outlet 52 and a liquid product in the electrolyte in the second chamber 12.

Comparative example 1

High value chemicals were prepared using ethane and oxygen in the same manner as in example 1, except that HClO ₄ was not added to the electrolyte.

Comparative example 2

High value chemicals were prepared using ethane and oxygen in the manner of example 1, except that no oxygen was introduced.

The production rates of the products prepared in the above examples and comparative examples were examined.

Wherein, FIG. 3 is a comparative graph of the test results of examples 1-6, it can be seen that the product formation rate also gradually increases with increasing applied voltage. Therefore, the application can control the applied voltage in the electrolysis process and effectively regulate and control the activation performance of alkane. If the voltage is relatively low, there may be poor alkane activation activity; if the voltage is relatively high, the copper dissolution rate may be too high, the stability of the electrolytic cell is affected, and long-time operation of the electrolytic cell cannot be ensured.

FIG. 4 is a graph comparing the results of the tests of example 1, comparative example 1 and examples 7-9, and it can be seen that the rate of product formation increases with increasing concentration of HClO ₄ in the electrolyte; when the concentration of HClO ₄ was increased to 1.0mol/L, the rate of product formation was not changed much until it was 2.0 mol/L.

Fig. 5 is a graph comparing the test results of example 1, comparative example 2 and examples 10 to 14, and it can be seen that the product formation rate is increased with the increase of the oxygen ratio. At an oxygen content of 30%, the rate of product formation reached a maximum. After further increasing the oxygen content to 50%, the rate of product formation continues to decrease due to the lack of alkane content.

FIG. 6 is a graph showing the comparison of the test results of examples 1 and 15-19, in which when Cu (ClO ₄)₂) increases from 0mol/L to 0.1mol/L, the generation rate of the product is not greatly changed, but the consumption of hydrogen ions exceeds 0.2mol/L in the reaction process, and when Cu (ClO ₄)₂) increases from 0.1mol/L to 0.8mol/L, the generation rate of the product is continuously reduced, and the consumption of hydrogen ions is less than 0.1mol/L in the reaction process.

FIG. 7 is a graph showing the results of the reaction conducted for 10 hours in example 20 of the present application, and it can be seen that the rate of formation of the product was always stable during the reaction for 10 hours.

According to the embodiment and the comparative example, the electrochemical method is adopted to oxidize alkane to prepare high-added-value chemicals, the first electrode and the second electrode both comprise copper, copper is adopted as a catalyst, and a large number of active sites can be formed by combining oxygen and an acidic solution at normal temperature and normal pressure, so that the alkane activating reaction under mild conditions can be realized, and the first electrode is dissolved along with the copper electrode in the process of electrochemically activating alkane; copper ions dissolved in the electrolyte are simultaneously deposited on the second electrode, so that the copper catalyst is stably and efficiently recycled, the process of preparing high-added-value chemical products by electrochemically activating alkane for a long time with high performance is realized, and copper materials are cheap and easy to obtain. Therefore, the application has the advantages of simple method, low cost, easy scale and the like.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the invention, which are described in detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.

Claims

1. A process for oxidizing an alkane, comprising:

2. The method of oxidizing an alkane of claim 1 wherein the electrolyte meets at least one of the following conditions:

(1) The acidic material comprises at least one of sulfuric acid, perchloric acid, phosphoric acid, hydrochloric acid, hydrobromic acid, and hydroiodic acid;

(2) The concentration of hydrogen ions in the electrolyte is 1 multiplied by 10 ^-7 mol/L to 2.0mol/L.

3. The method of oxidizing an alkane of claim 1 wherein the electrolyte further comprises a copper salt.

4. A method of oxidizing an alkane as claimed in claim 3 wherein the electrolyte further satisfies at least one of the following conditions:

(1) The copper salt includes at least one of Cu (ClO ₄)₂、CuSO₄ and CuCl ₂;

(2) The molar concentration of the copper salt in the electrolyte is 0.05 mol/L-0.8 mol/L.

5. The method of oxidizing an alkane of claim 1, wherein the alkane comprises at least one of a chain alkane and a cyclic alkane.

6. The method of oxidizing an alkane of claim 1, wherein the product of the oxidation of the alkane comprises at least one of an alkene, an alkyne, an alcohol, a carboxylic acid, a ketone, an aldehyde, an ester, a phenol, and an ether.

7. The oxidation process of an alkane of claim 1 wherein the oxidant satisfies at least one of the following conditions:

(1) The oxidant comprises at least one of organic peroxide, ozone, hydrogen peroxide, oxygen and air;

(2) And the volume ratio of the oxidant is 5% -50% based on 100% of the total volume of the alkane and the oxidant.

8. The oxidation process of alkanes according to any one of claims 1-7, wherein said process satisfies at least one of the following conditions:

(1) The voltage applied in the method is a constant voltage; optionally, the voltage applied in the method is 0.4V-1.4V;

(2) The temperature of oxidation in the method is 10-40 ℃, and the pressure is 0.5 atm-1.5 atm.

9. A reaction apparatus for carrying out the oxidation process of an alkane as claimed in any one of claims 1 to 8, comprising:

10. The reaction apparatus of claim 9, wherein the electrolytic cell is divided into a first chamber and a second chamber, the first electrode being disposed within the first chamber and the second electrode being disposed within the second chamber;