JP2020023742A - Device of producing epoxy derivative, method of producing epoxy derivative, and method of producing epoxy-derivative production device - Google Patents

Abstract

To provide a technique of producing an epoxy derivative under a milder condition.SOLUTION: A device 10 of producing an epoxy derivative, comprises a solid polymer type electrolysis unit 100 and a supply section 44 that supplies the solid polymer type electrolysis unit 100 with a substrate. The solid polymer type electrolysis unit 100 produces an epoxy derivative by electrolytic oxidation of the substrate.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an epoxy derivative manufacturing apparatus, an epoxy derivative manufacturing method, and an epoxy derivative manufacturing apparatus manufacturing method.

Propylene oxide (propylene oxide, C ₃ H ₆ O), one of the epoxy derivatives, is in enormous demand as a raw material for polyester and the like. On the other hand, the propylene oxide synthesis reaction was typical of the highly difficult partial oxidation reaction.

  From old times to the present, propylene oxide is generally synthesized by a chlorohydrin method or an oxirane method. However, the chlorohydrin method has problems that the apparatus is severely corroded by chlorine water and that a large amount of waste liquid must be treated. In addition, the oxirane method has a problem that it consumes much energy due to a multi-step process, and a large amount of alcohol as a by-product is generated from peroxide. On the other hand, for example, Non-Patent Document 1 proposes a method of synthesizing propylene oxide at 230 ° C. and about 30 atm using oxygen as an oxidizing agent and a silver catalyst.

Ind. Eng. Chem. Res. 2006, 45, 3447-3459

  Since the synthesis method disclosed in Non-Patent Document 1 is performed under high-temperature and high-pressure conditions, there is a problem that a combustion reaction of propylene with oxygen occurs as a side reaction. The present inventors have conducted intensive studies on the production of an epoxy derivative containing propylene oxide, and as a result, have arrived at a novel production technique capable of producing an epoxy derivative under milder conditions.

  The present invention has been made in view of such circumstances, and one of its objects is to provide a technique for producing an epoxy derivative under milder conditions.

  One embodiment of the present invention is an apparatus for producing an epoxy derivative. This manufacturing apparatus includes a solid polymer electrolyte unit and a supply unit that supplies a substrate to the solid polymer electrolyte unit. The polymer electrolyte unit produces an epoxy derivative by subjecting a substrate to electrolytic oxidation.

  Another embodiment of the present invention is a method for producing an epoxy derivative. This production method includes producing an epoxy derivative by subjecting a substrate to electrolytic oxidation using a solid polymer electrolyte unit.

Another embodiment of the present invention is a method for manufacturing an epoxy derivative manufacturing apparatus. This manufacturing method comprises: an anode including an anode catalyst layer; a cathode including a cathode catalyst layer; and a solid polymer electrolyte unit having a solid polymer electrolyte membrane provided between the anode and the cathode; A method for producing an epoxy derivative producing apparatus in which a solid polymer electrolyte unit performs electrolytic oxidation of a substrate to produce an epoxy derivative, wherein PtO ₂ is subjected to a reduction treatment to prepare PtO, Including in the anode catalyst layer.

  It should be noted that any combination of the above-described components, and the components and expressions of the present invention are mutually replaced between a method, an apparatus, a program, a temporary or non-temporary storage medium storing the program, a system, and the like. Is also effective as an aspect of the present invention.

  According to the present invention, an epoxy derivative can be produced under milder conditions.

It is a schematic diagram which shows the manufacturing apparatus of the epoxy derivative which concerns on embodiment. It is sectional drawing which shows schematic structure of a solid polymer electrolyte unit. It is a schematic diagram which shows the electrolyzer used for the electrolysis experiment.

  Hereinafter, the present invention will be described based on preferred embodiments with reference to the drawings. The embodiments are illustrative and do not limit the invention, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention. The same or equivalent components, members, and processes shown in each drawing are denoted by the same reference numerals, and the repeated description will be omitted as appropriate. Further, the scale and shape of each part shown in each figure are set for convenience in order to facilitate the description, and are not to be construed as being limited unless otherwise noted. In addition, when terms such as “first” and “second” are used in the present specification or claims, the terms do not indicate any order or importance unless otherwise specified, and a certain configuration may be used. It is for distinguishing from the other configuration. In each of the drawings, some of the members that are not important for describing the embodiments are omitted.

  FIG. 1 is a schematic view showing an apparatus for producing an epoxy derivative according to an embodiment. In FIG. 1, the structure of the solid polymer electrolyte unit is shown in a simplified manner. The epoxy derivative production device 10 (epoxy derivative production device) is a device for producing an epoxy derivative by electrolytically oxidizing a substrate, and includes a solid polymer electrolyte unit 100, a power control unit 20, a water storage tank 30, and a substrate storage tank. 40 and a control unit 60 are provided as main components. Hereinafter, the production apparatus 10 for an epoxy derivative will be simply referred to as “production apparatus 10” as appropriate.

  The power control unit 20 is, for example, a DC / DC converter that converts an output voltage of a power source into a predetermined voltage. A positive output terminal of the power control unit 20 is connected to an anode (anode) 130 of the polymer electrolyte unit 100. The negative output terminal of the power control unit 20 is connected to the cathode (negative electrode) 120 of the polymer electrolyte unit 100. As a result, a predetermined voltage is applied between the anode 130 and the cathode 120 of the polymer electrolyte unit 100.

  The power control unit 20 may be provided with a reference electrode for the purpose of detecting positive and negative potentials. In this case, the reference electrode input terminal is connected to the reference electrode 112 provided on the solid polymer electrolyte membrane 110. The reference electrode 112 is provided in a region of the solid polymer electrolyte membrane 110 separated from the cathode 120 and the anode 130 so as to be in contact with the solid polymer electrolyte membrane 110. Reference electrode 112 is electrically isolated from cathode 120 and anode 130.

  The reference electrode 112 is held at the reference electrode potential. The reference electrode potential in the present application means a potential with respect to a reversible hydrogen electrode (RHE) (reference electrode potential = 0 V). Note that the reference electrode potential may be a potential with respect to the Ag / AgCl electrode (reference electrode potential = 0.199 V). The reference electrode 112 is preferably provided on the surface of the solid polymer electrolyte membrane 110 on the anode 130 side.

  The current flowing between the cathode 120 and the anode 130 is detected by the current detection unit 113. The current detection unit 113 is configured by, for example, a conventionally known ammeter. The current value detected by the current detection unit 113 is input to the control unit 60, and is used for the control of the power control unit 20 by the control unit 60. The potential difference between the reference electrode 112 and the anode 130 is detected by the voltage detection unit 114. The voltage detection unit 114 is configured by, for example, a conventionally known voltmeter. The value of the potential difference detected by the voltage detection unit 114 is input to the control unit 60 and used for control of the power control unit 20 by the control unit 60. Note that, if necessary, the voltage detection unit 114 may detect a potential difference between the reference electrode 112 and the cathode 120.

  The control unit 60 controls the electric potential of the polymer electrolyte unit 100. That is, control unit 60 adjusts the potential of cathode 120 and / or anode 130 to a predetermined potential. The control unit 60 is realized by elements and circuits such as a CPU and a memory of a computer as a hardware configuration, and is realized by a computer program and the like as a software configuration. This is naturally understood by those skilled in the art. The control unit 60 controls the output of the positive output terminal and the negative output terminal of the power control unit 20 so that the potential of the cathode 120 and / or the anode 130 becomes a predetermined potential.

  The water storage tank 30 stores, for example, ion-exchanged water, pure water, or an aqueous solution obtained by adding an acid such as sulfuric acid, nitric acid, hydrochloric acid, or hydrofluoric acid (hereinafter referred to as “cathode solution” as appropriate). The catholyte stored in the water storage tank 30 is supplied to the cathode 120 of the polymer electrolyte unit 100 by the first supply device 32. As the first supply device 32, for example, various pumps such as a gear pump or a cylinder pump, or a free-flow type device or the like can be used.

  A circulation path 34 is provided between the water storage tank 30 and the cathode 120. The circulation path 34 includes a forward path 34a connecting the water storage tank 30 and the cathode 120 upstream of the cathode 120 in the flow of the catholyte, and a cathode 120 and the water storage tank 30 downstream of the cathode 120 in the flow of the catholyte. And a return path portion 34b connecting the two. A first supply device 32 is provided in the middle of the outward path portion 34a.

  The catholyte is supplied to the cathode 120 via the outward path 34a. The unreacted catholyte at the cathode 120, the hydrogen gas generated by the electrode reaction at the cathode 120, and other by-product gases are returned to the water storage tank 30 via the return path 34b. A gas-liquid separation unit (not shown) is provided in the middle of the return path 34b, and hydrogen gas and by-product gas are separated by the gas-liquid separation unit. Note that the return path 34b can be omitted.

  The substrate storage tank 40 stores the substrate. Examples of the substrate used in the present embodiment include an olefin compound. The olefin compound may be any olefin having an unsaturated bond. Olefins have at least one double bond. Therefore, a diene having two double bonds or an olefin having three or more double bonds may be used. The double bond may be inside or at the end of the main chain. Further, the olefin may be an aliphatic compound, a cyclic compound or an aromatic compound. Specific examples of the substrate include ethylene, propylene, butene, cyclohexene, styrene and the like. Epoxy derivatives obtained with these substrates, that is, compounds having an epoxy group (epoxy compounds) are ethylene oxide, propylene oxide, butene oxide, cyclohexene oxide, and styrene oxide.

  The substrate stored in the substrate storage tank 40 is supplied to the anode 130 of the polymer electrolyte unit 100 by the second supply device 42. The substrate storage tank 40 and the second supply device 42 constitute a supply unit 44 for supplying a substrate to the polymer electrolyte unit 100. When the substrate is in a gaseous state at normal temperature and normal pressure, such as propylene, as the second supply device 42, for example, various gas flow controllers, a natural flow type device, or the like can be used.

  A circulation path 46 is provided between the substrate storage tank 40 and the anode 130. The circulation path 46 connects the substrate 130 and the substrate storage tank 40 upstream of the anode 130 in the substrate flow and connects the anode 130 to the substrate storage tank 40 downstream of the anode 130 in the substrate flow. And a return section 46b. The second supply device 42 is provided in the middle of the outward path 46a.

  The substrate is supplied to the anode 130 via the outward path 46a. The epoxy derivative generated by the electrolytic oxidation of the substrate at the anode 130 and the unreacted substrate are returned to the substrate storage tank 40 via the return path 46b. A gas-liquid separation unit (not shown) is provided in the middle of the return path 46b, and the by-product gas generated at the anode 130 is separated by the gas-liquid separation unit. Note that the return path 46b can be omitted.

  FIG. 2 is a cross-sectional view illustrating a schematic configuration of the solid polymer electrolyte unit 100. The polymer electrolyte unit 100 of the present embodiment is a polymer electrolyte tank having an anode chamber on one side of a film-shaped electrolyte membrane and a cathode chamber on the other side. More specifically, the solid polymer electrolyte unit 100 includes a membrane electrode assembly 102 and a pair of separators 150a and 150b that sandwich the membrane electrode assembly 102. The membrane electrode assembly 102 has a solid polymer electrolyte membrane 110, a cathode 120, and an anode 130.

  The solid polymer electrolyte membrane 110 is provided between the anode 130 and the cathode 120. The solid polymer electrolyte membrane 110 is formed of a material (ionomer) having proton conductivity. While the polymer electrolyte membrane 110 selectively conducts protons, it prevents substances from being mixed or diffused between the cathode 120 and the anode 130. Further, the solid polymer electrolyte membrane 110 can transmit cathode water.

  The thickness of the solid polymer electrolyte membrane 110 is, for example, 5 to 300 μm. By setting the thickness of the solid polymer electrolyte membrane 110 to 5 μm or more, the barrier properties of the solid polymer electrolyte membrane 110 can be secured, and the occurrence of cross leak of a substrate or the like can be more reliably suppressed. Further, by setting the thickness of the solid polymer electrolyte membrane 110 to 300 μm or less, it is possible to suppress the ion transfer resistance from becoming excessive.

  The solid polymer electrolyte membrane 110 preferably contains perfluorosulfonic acid as a material having proton conductivity. For example, the solid polymer electrolyte membrane 110 is made of a polymer of perfluorosulfonic acid. Examples of the polymer include Nafion (registered trademark) and Flemion (registered trademark). The solid polymer electrolyte membrane 110 may be mixed with a reinforcing material such as porous PTFE (polytetrafluoroethylene). By introducing the reinforcing material, the dimensional stability of the polymer electrolyte membrane 110 can be improved. Thereby, the durability of the solid polymer electrolyte membrane 110 can be improved. Further, crossover of a substrate or the like can be suppressed.

  The cathode 120 is an electrode that generates hydrogen by reducing protons, and is disposed on one side of the solid polymer electrolyte membrane 110. In the present embodiment, cathode 120 is provided to be in contact with one main surface of solid polymer electrolyte membrane 110. The cathode 120 has a structure in which a cathode catalyst layer 122 and a diffusion layer 124 are stacked. The cathode catalyst layer 122 is disposed closer to the solid polymer electrolyte membrane 110 than the diffusion layer 124.

The cathode catalyst layer 122 is in contact with one main surface of the solid polymer electrolyte membrane 110. Cathode catalyst layer 122 contains a catalyst metal for reducing protons. For example, the cathode catalyst layer 122 includes at least one catalyst metal selected from the group consisting of Pt, Au, Ag, Pd, Rh, Ru, Fe, and Ni. The catalyst metal is supported on a catalyst carrier composed of an electron conductive material. By supporting the catalyst metal on the catalyst carrier, the surface area of the cathode catalyst layer 122 can be increased. In addition, aggregation of the catalyst metal can be suppressed. The electron conductivity of the electron conductive material used for the catalyst carrier is preferably 1.0 × 10 ⁻² S / cm or more. By setting the electron conductivity of the electron conductive material to 1.0 × 10 ⁻² S / cm or more, electron conductivity can be more reliably given to the cathode catalyst layer 122.

  Examples of the catalyst carrier include an electron conductive material containing, as a main component, any of porous carbon, porous metal, and porous metal oxide. Examples of the porous carbon include carbon black such as Ketjen Black (registered trademark), acetylene black, furnace black, and Vulcan (registered trademark). Examples of the porous metal include Pt black, Pd black, and Pt metal precipitated in a fractal state. Examples of the porous metal oxide include oxides of Ti, Zr, Nb, Mo, Hf, Ta, and W. In addition, porous metal compounds such as nitrides, carbides, oxynitrides, carbonitrides, and partially oxidized carbonitrides of metals such as Ti, Zr, Nb, Mo, Hf, Ta, and W are used as catalyst carriers. Can also be used.

  Preferably, the catalyst support supporting the catalyst metal is coated with an ionomer. Thereby, the ion conductivity of the cathode 120 can be improved. Examples of the ionomer include perfluorosulfonic acid polymers such as Nafion (registered trademark) and Flemion (registered trademark). The thickness of the cathode catalyst layer 122 is, for example, 1 to 100 μm. By setting the thickness of the cathode catalyst layer 122 within the above range, an increase in proton transfer resistance can be suppressed.

  The cathode catalyst layer 122 is prepared, for example, by mixing a catalyst component powder, a catalyst carrier, and a solvent such as water to prepare a catalyst ink. The obtained catalyst ink, a conductive filler such as carbon nanotubes, and a binder are mixed together. The catalyst paste can be prepared by mixing to prepare a catalyst paste, and forming the catalyst paste into a sheet. In addition, it can also be prepared by applying a catalyst ink to the diffusion layer 124, drying it, and then hot pressing it. Further, the cathode catalyst layer 122 may be formed on the solid polymer electrolyte membrane 110.

  The diffusion layer 124 has a function of uniformly diffusing the catholyte supplied from the separator 150 a into the cathode catalyst layer 122. Examples of a material forming the diffusion layer 124 include a carbon woven fabric (carbon cloth), a carbon nonwoven fabric, and carbon paper. The carbon cloth is a bundle of hundreds of thin carbon fibers having a diameter of several μm, and this bundle is formed into a woven fabric. Carbon paper is obtained by sintering a carbon raw material fiber as a thin film precursor by a papermaking method. The thickness of the diffusion layer 124 is preferably 50 to 1000 μm.

  The separator 150 a is stacked on the main surface of the cathode 120 opposite to the solid polymer electrolyte membrane 110. The separator 150a is made of, for example, a carbon resin, a corrosion resistance of a Cr-Ni-Fe system, a Cr-Ni-Mo-Fe system, a Cr-Mo-Nb-Ni system, a Cr-Mo-Fe-W-Ni system, or a Ti system. It can be formed of an alloy. On the surface of the separator 150a on the diffusion layer 124 side, one or a plurality of groove-shaped flow paths 152a are provided. The forward path 34a and the backward path 34b are connected to the flow path 152a. A cathode chamber is defined by the separator 150a, the solid polymer electrolyte membrane 110, and a frame-shaped spacer 126 disposed therebetween, and the cathode chamber accommodates the cathode catalyst layer 122 and the diffusion layer.

  The catholyte flows into the cathode chamber channel 152a via the outward path 34a. The catholyte infiltrates into the diffusion layer 124 from the channel 152a. Then, it flows into the anode 130 side via the cathode catalyst layer 122 and the solid polymer electrolyte membrane 110. The unreacted catholyte flows out of the cathode chamber through the return path part 34b, and is returned to the water storage tank 30. The form of the flow channel 152a is not particularly limited, but for example, a linear flow channel, a serpentine flow channel, or the like can be adopted. Alternatively, the separator 150a may have a porous layer, and the channels 152a may be configured by gaps in the porous layer.

  The anode 130 is an electrode for electrolytically oxidizing a substrate to generate an epoxy derivative, and is disposed on the other side of the solid polymer electrolyte membrane 110, that is, on the side opposite to the side on which the cathode 120 is disposed. In the present embodiment, anode 130 is provided so as to be in contact with the other main surface of solid polymer electrolyte membrane 110. The anode 130 has a structure in which an anode catalyst layer 132 and a diffusion layer 134 are stacked. The anode catalyst layer 132 is disposed closer to the solid polymer electrolyte membrane 110 than the diffusion layer 134 is.

  The anode catalyst layer 132 is in contact with the other main surface of the solid polymer electrolyte membrane 110. The anode catalyst layer 132 includes a catalyst metal for oxidizing a substrate. Preferably, anode catalyst layer 132 includes at least one catalyst metal selected from the group consisting of Pt, Pd, Ir, Rh, and Ru. More preferably, anode catalyst layer 132 contains Pt. When the anode catalyst layer 132 contains these catalyst metals, an epoxy derivative can be efficiently generated.

When the anode catalyst layer 132 contains Pt, the anode catalyst layer 132 contains PtO. For example, when the anode catalyst layer 132 is analyzed by an X-ray photoelectron spectrometer (XPS), the ratio of the peak area of PtO 4f _{7/2 to} the total peak area of Pt is preferably 2% or more. In the anode catalyst layer 132, Pt can take a state of Pt (metal simple substance), PtO, or PtO ₂ . Among them, it is considered that PtO functions as a main active site of the electrolytic oxidation of the substrate. Therefore, by setting the amount of PtO in the anode catalyst layer 132 such that the peak area of PtO 4f _7/2 becomes 2% or more of the peak area of the entire Pt, it is possible to increase the production efficiency of the epoxy derivative. it can.

PtO can by oxidation of Pt, or produced by partial reduction of PtO _2. The oxidation of Pt is carried out by a gas phase oxidation treatment of heating (firing) Pt in the presence of an oxygen-containing gas such as air, or a liquid phase oxidation treatment of oxidizing Pt using an oxidizing agent such as hydrogen peroxide. Can be. Partial reduction of PtO ₂ is a gas phase reduction process to put PtO ₂ in the presence and under the predetermined temperature of the reducing gas such as hydrogen or hydrazine, liquid phase reduction for reducing the PtO ₂ using a reducing agent such as NaBH ₄ It can be implemented by processing.

Preferably, the method for manufacturing the epoxy derivative manufacturing apparatus 10 includes performing PtO ₂ by reducing PtO ₂ to prepare PtO, and including PtO in the anode catalyst layer 132. Preferably, a reducing agent is used in the PtO ₂ reduction treatment. Also, preferably, the reducing agent is hydrazine. When the theoretical amount of PtO ₂ reduced to 100% Pt is 1 equivalent, the amount of the reducing agent used is preferably 0.1 equivalent or more and less than 1 equivalent. When the amount of the reducing agent used is 0.1 equivalent or more, the partial reduction of PtO ₂ can be performed more reliably. In addition, when the amount of the reducing agent used is less than 1 equivalent, the organic substance selectivity can be increased. Here, the organic substance selectivity means a molar ratio (%) of a target organic substance to the entire organic substance generated by electrolytic oxidation of a substrate. In the case where PtO ₂ is reduced by a gas phase reduction treatment, the temperature during the reduction treatment is preferably lower than 50 ° C.

  The catalyst metal may be supported by a catalyst carrier composed of an electron conductive material. Examples of the catalyst carrier include porous carbon, porous metal, and porous metal oxide. Preferably, the catalytic metal is coated with an ionomer. Thereby, the ionic conductivity of the anode 130 can be improved. Examples of the ionomer include perfluorosulfonic acid polymers such as Nafion (registered trademark) and Flemion (registered trademark). The thickness of the anode catalyst layer 132 is, for example, 1 to 100 μm.

  The anode catalyst layer 132 can be produced by, for example, preparing a catalyst paste by mixing a catalyst component powder and a binder, and forming the catalyst paste into a sheet. In addition, it can also be manufactured by applying a catalyst ink to the diffusion layer 134, drying the coating, and then hot pressing the coating. Further, the anode catalyst layer 132 may be formed on the solid polymer electrolyte membrane 110.

  The diffusion layer 134 has a function of uniformly diffusing the substrate supplied from the separator 150b into the anode catalyst layer 132. The material forming the diffusion layer 134 preferably has a high affinity for the substrate. Examples of the material forming the diffusion layer 134 include a carbon woven fabric (carbon cloth), a carbon nonwoven fabric, and carbon paper. The thickness of the diffusion layer 134 is preferably 50 to 1000 μm.

  The separator 150b is stacked on the main surface of the anode 130 opposite to the solid polymer electrolyte membrane 110. The separator 150b can be made of the same material as the separator 150a. On the surface of the separator 150b on the diffusion layer 134 side, one or a plurality of groove-shaped flow paths 152b are provided. The outward path 46a and the return path 46b are connected to the flow path 152b. An anode chamber is defined by the separator 150b, the solid polymer electrolyte membrane 110, and a frame-shaped spacer 136 disposed therebetween, and the anode chamber accommodates the anode catalyst layer 132 and the diffusion layer 134.

  The substrate flows into the channel 152b of the anode chamber via the outward path 46a. The substrate penetrates into the diffusion layer 134 from the channel 152b. The product of the electrolytic oxidation reaction in the anode catalyst layer 132 and the unreacted substrate flow out of the anode chamber through the return path 46b, and are returned to the substrate storage tank 40. The form of the channel 152b is the same as that of the channel 152a.

The polymer electrolyte unit 100 electrolytically oxidizes a substrate to produce an epoxy derivative. The reaction in the solid polymer electrolyte unit 100 when propylene (C ₃ H ₆ ) is used as a substrate is as follows.
<Electrode reaction at anode 130>
^{_{H 2 O → 2H + + O}} 2-
^{_{C 3 H 6 + O 2- →}} C 3 H 6 O + 2e -
<Electrode reaction at cathode 120>
2H ⁺ + 2e ⁻ → H ₂
<All reactions>
C ₃ H ₆ + H ₂ O → C ₃ H ₆ O + H ₂

That is, first, the catholyte supplied to the cathode 120 passes through the solid polymer electrolyte membrane 110 and reaches the anode catalyst layer 132. In the anode catalyst layer 132, protons (H ⁺ ) and oxygen ions (O ²⁻ ) are generated from water (H ₂ O) in the catholyte solution. The generated oxygen ions react with propylene as a substrate supplied to the anode catalyst layer 132 by the supply unit 44 to generate propylene oxide (C ₃ H ₆ O) as an epoxy derivative and electrons (e ⁻ ). You.

Protons generated in the anode catalyst layer 132 are supplied to the cathode 120 via the solid polymer electrolyte membrane 110. The electrons generated in the anode catalyst layer 132 are supplied to the cathode 120 via an external circuit. Then, in the cathode catalyst layer 122, hydrogen gas (H ₂ ) is generated from protons and electrons. The electrode reaction at the anode 130 and the electrode reaction at the cathode 120 proceed in parallel.

  In the electrolytic oxidation of the substrate by the polymer electrolyte unit 100, the control unit 60 sets the potential in the electrolytic oxidation to preferably more than 1.2 V, more preferably 1.4 V or more. More specifically, the control unit 60 sets the potential of the anode 130 to preferably more than 1.2 V, more preferably 1.4 V or more. Thereby, an epoxy derivative can be produced more efficiently.

[Method for producing epoxy derivative]
The method for producing an epoxy derivative according to the present embodiment includes producing an epoxy derivative by electrolytically oxidizing a substrate using the polymer electrolyte unit 100. More specifically, a substrate is supplied to the anode 130, and a catholyte is supplied to the cathode 120. Then, a predetermined voltage is applied between the anode 130 and the cathode 120 of the polymer electrolyte unit 100 by the power control unit 20. At this time, the potential of the anode 130 is controlled to preferably exceed 1.2 V, and more preferably to 1.4 V or more.

  As a result, in the anode catalyst layer 132, the water moving from the cathode 120 side is decomposed, and protons and oxygen ions are generated. Further, the generated oxygen ions react with the substrate to generate an epoxy derivative. The generated protons pass through the solid polymer electrolyte membrane 110 and move to the cathode 120 side. Then, in the cathode catalyst layer 122, hydrogen gas is generated from the protons.

  As described above, the epoxy derivative manufacturing apparatus 10 according to the present embodiment includes the solid polymer electrolyte unit 100 and the supply unit 44 that supplies a substrate to the polymer electrolyte unit 100. The solid polymer electrolyte unit 100 includes an anode 130 including an anode catalyst layer 132, a cathode 120 including a cathode catalyst layer 122, and a solid polymer electrolyte membrane 110 provided between the anode 130 and the cathode 120. The supply unit 44 supplies a substrate to the anode 130. The polymer electrolyte unit 100 electrolytically oxidizes the substrate to produce an epoxy derivative. The method for producing an epoxy derivative according to the present embodiment includes producing an epoxy derivative by subjecting a substrate to electrolytic oxidation using the solid polymer electrolyte unit 100.

  As described above, in the present embodiment, since the epoxy derivative is synthesized using the polymer electrolyte unit 100, the electrolytic oxidation of the substrate is performed using water as an oxidizing agent under mild conditions at a lower temperature and a lower pressure than the conventional case. Let it proceed. Therefore, generation of by-products can be suppressed.

  In addition, propylene oxide, which is an example of an epoxy derivative, has conventionally been generally synthesized by a chlorohydrin method or an oxirane method. As described above, these processes had problems such as corrosion of the apparatus, necessity of treating a large amount of waste liquid, low energy consumption efficiency, and a large amount of by-products. On the other hand, in the present embodiment, since the epoxy derivative is synthesized using the solid polymer electrolyte unit 100, the necessity for measures against corrosion is low, and the epoxy derivative can be synthesized with a simpler device structure. Further, the amount of waste liquid can be reduced. In addition, since the electrode reaction at the anode 130 and the electrode reaction at the cathode 120 occur in parallel, the epoxy derivative can be synthesized by simpler steps.

  The anode catalyst layer 132 preferably contains at least one kind of catalyst metal selected from the group consisting of Pt, Pd, Ir, Rh and Ru, and more preferably contains Pt. Thereby, an epoxy derivative can be produced more reliably.

When the anode catalyst layer 132 contains Pt, the ratio of the peak area of PtO 4f _{7/2 to} the entire peak area of Pt when analyzed by XPS is preferably 2% or more. Thereby, the production efficiency of the epoxy derivative can be increased.

  In addition, the epoxy derivative manufacturing apparatus 10 includes a control unit 60 that controls the potential of the polymer electrolyte unit 100. The control unit 60 controls the potential of the anode 130 at the time of electrolytic oxidation to be higher than 1.2V. Thereby, the production efficiency of the epoxy derivative can be increased.

  Hereinafter, although an example of the present invention is described, an example is only an illustration for explaining suitably the present invention, and does not limit the present invention at all.

(Example 1)
<Cathode catalyst ink: Preparation of 50 wt% Pt / XC72>
7.50 mL of an aqueous solution of H ₂ [PtCl ₆ ] · 6H ₂ O (19.1 mg / mL) and 150 mg of carbon black (product name: XC72, manufactured by vulcan) are added to 50 mL of ion-exchanged water, and stirred for 1 hour. did. Subsequently, the obtained mixture was heated at 80 to 90 ° C. to evaporate water, and then dried at 70 ° C. overnight. The obtained solid was subjected to a hydrogen reduction treatment under a stream of H ₂ gas to obtain a cathode catalyst ink. The flow rate of the H ₂ gas in the hydrogen reduction treatment was set to 20 mL / min. After the treatment at 150 ° C. for 1 hour, the treatment was performed at 300 ° C. for 2 hours.

<Preparation of cathode>
In a mortar heated to 60 ° C. on a hot plate, 25 mg of carbon nanotubes (product name: VGCF, manufactured by Showa Denko KK), 25 mg of cathode catalyst ink (50 wt% Pt / XC72), and 5 mg of Teflon (registered trademark) powder as a binder And these were kneaded. The obtained paste was rolled on a stainless steel plate heated to 120 ° C. using a stainless steel roller. As a result, a cathode catalyst layer having a circular sheet shape having a diameter of 1.6 cm and a uniform thickness was obtained. Subsequently, a circular diffusion layer (product name: SGL25BC, manufactured by SGL Carbon Co., Ltd.) having a diameter of 1.6 cm was placed on a 50 ° C. hot plate. Then, the cathode catalyst layer was placed on the diffusion layer, and a mixed solution of 50 μL of Nafion (registered trademark) dispersion liquid (product name: DE1021, manufactured by DuPont) and 300 μL of acetone was applied to the cathode catalyst layer. Thereafter, the laminate of the diffusion layer and the cathode catalyst layer was dried under reduced pressure at 50 ° C. for 10 minutes using a rotary pump. Through the above steps, a cathode was obtained.

<Preparation of anode>
70 mg of Pt black (manufactured by Tanaka Kikinzoku) heated and oxidized at 350 ° C. for 2 hours in a muffle furnace and 1 mg of Teflon (registered trademark) powder as a binder were put into a mortar heated to 60 ° C. on a hot plate. These were kneaded. The obtained paste was rolled on a stainless steel plate heated to 120 ° C. using a stainless steel roller. Thus, an anode catalyst layer having a circular sheet shape having a diameter of 1.6 cm and a uniform thickness was obtained. Subsequently, a circular diffusion layer (product name: SGL25BC, manufactured by SGL Carbon Co., Ltd.) having a diameter of 1.6 cm was placed on a 50 ° C. hot plate. Then, the anode catalyst layer was placed on the diffusion layer, and a mixed solution of 50 μL of Nafion (registered trademark) dispersion liquid (product name: DE1021, manufactured by DuPont) and 300 μL of acetone was applied to the anode catalyst layer. Thereafter, the laminate of the diffusion layer and the anode catalyst layer was dried under reduced pressure at 50 ° C. for 10 minutes using a rotary pump. Through the above steps, an anode was obtained.

<Preparation of solid polymer electrolyte membrane>
A Nafion membrane (product name: nafion 117, manufactured by DuPont) was prepared. This Nafion membrane is of the K ⁺ type. For this reason, the Nafion membrane was subjected to a pretreatment to be converted into an H ⁺ type (proton type). Specifically, the Nafion membrane was cut out in a predetermined size and boiled in 3 wt% H ₂ O ₂ water for 1 hour. Thus, the organic components adhering to the Nafion film were removed by oxidation. Thereafter, the Nafion membrane was boiled for 1 hour in each of ion-exchanged water, 1M sulfuric acid, and ion-exchanged water, thereby ion-exchanging K ⁺ with H ⁺ to remove impurities. The treated Nafion membrane was stored in ion-exchanged water.

<Preparation of membrane electrode assembly>
The anode was placed on one side of the Nafion membrane with the catalyst layer in contact with the Nafion membrane. The cathode was placed on the other surface of the Nafion membrane such that the catalyst layer was in contact with the Nafion membrane. The obtained laminate was hot-pressed at 140 ° C. and 50 MPa for 10 minutes to bond the anode and the cathode to the Nafion membrane. Thereafter, the laminate was immersed in ion-exchanged water for 5 minutes, so that the Nafion membrane was sufficiently impregnated with water. Through the above steps, a membrane electrode assembly (MEA) was obtained.

<Electrolysis experiment>
FIG. 3 is a schematic diagram showing an electrolytic cell used in an electrolysis experiment. As shown in FIG. 3, an electrolytic oxidation experiment was performed using a two-chamber electrolytic cell in which the produced MEA was sandwiched between an anode chamber AN and a cathode chamber CA. 30 mL of ion-exchanged water (H ₂ O) was placed in the cathode chamber CA, and 30 mL of a dichloromethane (CH ₂ Cl ₂ ) solution and a magnetic stirrer (not shown) made of Teflon (registered trademark) were placed in the anode chamber AN.

While stirring the solution in the anode chamber AN with a stirrer, helium gas (He) was allowed to flow through the cathode chamber CA and the anode chamber AN at a flow rate (flow rate) of 40 mL / min for 10 minutes. Thus, the atmosphere in the cathode chamber CA and the atmosphere in the anode chamber AN were replaced with He. Thereafter, He is passed through the anode chamber AN at a flow rate of 40 mL / min and C ₃ H ₆ at a flow rate of 20 mL / min for 10 minutes to replace He in the anode chamber AN with a mixed gas of He and C ₃ H _6. did. He was allowed to flow through the cathode chamber CA at a flow rate of 40 mL / min for 10 minutes.

After the above pretreatment, He was passed through the anode chamber AN at a flow rate of 10 mL / min, C ₃ H ₆ was passed at a flow rate of 5 mL / min, and He was passed through the cathode chamber CA at a flow rate of 10 mL / min. Then, the anode potential was controlled to 1.6 V using a potentiostat (P / G stat.), And the constant potential electrolysis was performed at room temperature for 2 hours.

<Analysis of liquid phase product>
After the completion of the constant potential electrolysis, the components were analyzed by mixing the anode solution and the cold trap solution. Specifically, 0.5 mL of a dichloromethane solution containing 1-butanol (about 20 μmol) as a standard substance was added to the mixed solution, and each component in the mixed solution was detected using a flame ionization detector (FID). It was quantified by gas chromatography. From the analysis result of the liquid phase product, the production amount (yield) of propylene oxide (PO) as the target product was obtained. In addition, the number of moles of PO relative to the total number of moles of organic matter generated from the substrate, that is, the organic matter selectivity was calculated. In this experiment using C ₃ H ₆ as a substrate, the organic substances detected were PO and acetone. For this reason, the organic substance selectivity in this experiment corresponds to the ratio of the yield of PO (mol) to the total yield of PO and acetone (mol).

<Analysis of gas phase products>
Gas phase products of the anode (O _2, CO ₂₎ and gas-phase products at the cathode (CO ₂₎ was determined by gas chromatography using a thermal conductivity detector and (TCD) and the detector.

<Analysis of PtO amount in anode catalyst layer>
The amount of PtO in the anode catalyst layer was measured with an X-ray photoelectron spectrometer (XPS). Specifically, in the data obtained by subjecting the XPS measurement result to the waveform separation processing, the peak located near the binding energy of 74 eV is defined as the peak of the PtO 4f _7/2 orbit, and the area percentage of the peak with respect to all the peaks is calculated. did. The obtained area percentage was defined as the amount of PtO.

(Example 2)
The MEA fabrication, electrolysis experiment, and analysis were performed in the same manner as in Example 1 except that the heat treatment temperature of Pt black was set to 300 ° C.

(Example 3)
The MEA fabrication, electrolysis experiment, and analysis were performed in the same manner as in Example 1, except that the anode potential in the electrolysis experiment was 1.2 V.

(Example 4)
The MEA fabrication, electrolysis experiment, and analysis were performed in the same manner as in Example 1, except that the anode potential in the electrolysis experiment was 1.4 V.

(Example 5)
The MEA fabrication, electrolysis experiment and analysis were performed in the same manner as in Example 1, except that the anode potential in the electrolysis experiment was 1.5 V.

(Example 6)
The MEA fabrication, electrolysis experiment, and analysis were performed in the same manner as in Example 1, except that the anode potential in the electrolysis experiment was 1.7 V.

(Example 7)
MEA fabrication, electrolysis experiment and analysis were carried out in the same manner as in Example 1 except that PtO ₂ (manufactured by Wako Pure Chemical Industries, Ltd.) subjected to a predetermined reduction treatment was used in place of oxidized Pt black. did. The reduction treatment was performed at 25 ° C. for 2 hours under a 5% hydrogen stream (Ar dilution).

(Example 8)
Except that the temperature of the reduction treatment was set to 50 ° C., the MEA fabrication, electrolysis experiment, and analysis were performed in the same manner as in Example 7.

(Example 9)
Except that the temperature of the reduction treatment was 80 ° C., the MEA fabrication, electrolysis experiment, and analysis were performed in the same manner as in Example 7.

(Example 10)
MEA fabrication, electrolysis experiments and analysis were carried out in the same manner as in Example 1, except that Pt black not subjected to oxidation treatment was used.

(Example 11)
MEA fabrication, electrolysis experiments and analysis were carried out in the same manner as in Example 1 except that PtO ₂ (manufactured by Wako Pure Chemical Industries, Ltd.) not subjected to reduction treatment was used instead of Pt black.

(Example 12)
MEA fabrication, electrolysis experiments and analysis were carried out in the same manner as in Example 1, except that Pd black (manufactured by Wako Pure Chemical Industries, Ltd.) was used instead of Pt black.

(Example 13)
The MEA fabrication, electrolysis experiment and analysis were carried out in the same manner as in Example 1 except that Ir black (Mitsuwa Chemicals) was used instead of Pt black.

(Example 14)
MEA fabrication, electrolysis experiments and analysis were carried out in the same manner as in Example 7, except that PtO ₂ subjected to reduction treatment using hydrazine as a reducing agent was used in place of Pt black subjected to oxidation treatment. . PtO ₂ subjected to reduction treatment was obtained as follows. That is, PtO ₂ (manufactured by Wako Pure Chemical Industries, Ltd.) was added to 20 mL of ion exchange water at 50 ° C. Then, while this solution was stirred, 0.5 equivalent of hydrazine was added dropwise to the solution. The equivalent is an amount when the theoretical amount of PtO ₂ reduced to 100% Pt is one equivalent. After the addition of hydrazine, the solution was stirred for 30 minutes to reduce PtO ₂ . After the reduction treatment, the solution was subjected to suction filtration, and the residue was dried under reduced pressure. Thus, PtO ₂ subjected to a reduction treatment was obtained.

(Example 15)
The MEA fabrication, electrolysis experiment, and analysis were performed in the same manner as in Example 14, except that the anode potential in the electrolysis experiment was 1.7 V.

(Example 16)
The MEA fabrication, electrolysis experiment, and analysis were performed in the same manner as in Example 14, except that the anode potential in the electrolysis experiment was 1.8 V.

(Example 17)
The MEA fabrication, electrolysis experiment, and analysis were performed in the same manner as in Example 14, except that the amount of hydrazine dropped was 1 equivalent.

(Example 18)
The MEA fabrication, electrolysis experiment, and analysis were performed in the same manner as in Example 14, except that the amount of hydrazine dropped was 0.4 equivalent.

(Example 19)
MEA fabrication, electrolysis experiments and analysis were carried out in the same manner as in Example 14, except that the amount of hydrazine dropped was 0.3 equivalent.

(Example 20)
The MEA fabrication, electrolysis experiment, and analysis were performed in the same manner as in Example 14, except that the amount of hydrazine added was changed to 0.1 equivalent.

(Example 21)
MEA fabrication, electrolysis experiments and analysis were carried out in the same manner as in Example 14, except that 1 equivalent of NaBH ₄ was used instead of hydrazine as the reducing agent, and the reduction treatment temperature was 25 ° C.

  Table 1 shows the type of the anode catalyst, the anode potential, the amount of PtO, the amount of propylene oxide (PO) produced (yield), and the selectivity for organic substances in each example.

As shown in Table 1, from Examples 1 to 13, it was confirmed that propylene oxide (epoxy derivative) can be produced by electrolytic oxidation of a substrate using a solid polymer electrolyte unit. Further, from Examples 1, 7, 10 to 13, it was confirmed that when the anode contained PtO as a catalyst metal, the production amount of the epoxy derivative tended to increase. Further, from Examples 1, 2, 7 to 11, when the amount of PtO in the anode catalyst layer, that is, the peak area ratio of PtO 4f _7/2 is 2% or more, and further 2.4% or more, the epoxy derivative It was confirmed that the production amount increased.

In addition, from Examples 1, 3 to 6, it was confirmed that the amount of the epoxy derivative generated could be further increased by setting the anode potential to more than 1.2 V, and further to 1.4 V or more. In Examples 1 to 6 in which Pt black was oxidized and converted to PtO, and in Examples 7 to 9 and 14 to _{20 in} which PtO ₂ was reduced to PtO, the processing temperature, the amount of reducing agent, and the anode potential It was confirmed that the epoxy derivative can be synthesized with the same high yield by the adjustment.

Further, from Examples 7, 14 to 21, it was confirmed that when the anode catalyst layer was produced by the reduction treatment of PtO ₂ , the selectivity of organic substances tended to increase. Further, from Examples 8, 9, 14 to 21, the reduction of PtO ₂ using a reducing agent instead of a reducing gas has a higher organic substance selectivity than the reduction processing of PtO ₂ using a reducing gas. It was confirmed that there was a tendency to increase. Further, from Examples 17 and 21, it was confirmed that when hydrazine was used as the reducing agent, the PO yield was larger than when NaBH ₄ was used. Also, from Examples 14, 17 to 20, it was confirmed that when the amount of the reducing agent used is less than 1 equivalent, the organic substance selectivity increases. In addition, from Examples 7 to 9, it was confirmed that in the case of a reduction treatment using a reducing gas, the organic substance selectivity was significantly increased by setting the reduction temperature to less than 50 ° C, more preferably 25 ° C or less. Was.

  It should be noted that those skilled in the art will understand from the results of the examples using Pt, Pd, and Ir as the anode catalyst metals that similar results can be obtained when Rh and Ru are used as the catalyst metals. be able to.

  The embodiment of the invention has been described above in detail. The above-described embodiments are merely specific examples for implementing the present invention. The contents of the embodiments do not limit the technical scope of the present invention, and many design changes such as component changes, additions, and deletions are made without departing from the spirit of the invention defined in the claims. Is possible. In the above-described embodiment, such contents that can be changed in design are emphasized with notations such as “of the present embodiment” and “in the present embodiment”. The design change is allowed even for the contents without the. Any combination of the above components is also effective as an aspect of the present invention. The hatching attached to the cross section of the drawing does not limit the material to which hatching is applied.

  DESCRIPTION OF SYMBOLS 10 Epoxy derivative manufacturing apparatus, 44 Supply part, 60 control part, 100 solid polymer electrolyte unit, 110 solid polymer electrolyte membrane, 120 cathode, 122 cathode catalyst layer, 130 anode, 132 anode catalyst layer.

Claims (14)

A polymer electrolyte unit;
A supply unit for supplying a substrate to the solid polymer electrolyte unit,
The apparatus for producing an epoxy derivative, wherein the solid polymer electrolyte unit produces an epoxy derivative by electrolytically oxidizing the substrate. The solid polymer electrolyte unit,
An anode including an anode catalyst layer;
A cathode including a cathode catalyst layer;
A solid polymer electrolyte membrane provided between the anode and the cathode,
The apparatus of claim 1, wherein the supply unit supplies the substrate to the anode.   The apparatus of claim 2, wherein the anode catalyst layer includes at least one catalyst metal selected from the group consisting of Pt, Pd, Ir, Rh, and Ru.   The apparatus for producing an epoxy derivative according to claim 3, wherein the anode catalyst layer contains Pt. The apparatus for producing an epoxy derivative according to claim 4, wherein when the anode catalyst layer is analyzed with an X-ray photoelectron spectrometer, the ratio of the peak area of PtO 4f _{7/2 to} the entire peak area of Pt is 2% or more. . A control unit for controlling the potential of the solid polymer electrolyte unit,
The apparatus for producing an epoxy derivative according to claim 1, wherein the control unit sets the potential in the electrolytic oxidation to more than 1.2 V.   The apparatus for producing an epoxy derivative according to claim 2, wherein the solid polymer electrolyte membrane contains perfluorosulfonic acid.   A method for producing an epoxy derivative, comprising producing an epoxy derivative by electrolytically oxidizing a substrate using a polymer electrolyte unit. An anode including an anode catalyst layer, a cathode including a cathode catalyst layer, and a solid polymer electrolyte unit having a solid polymer electrolyte membrane provided between the anode and the cathode;
A supply unit for supplying a substrate to the anode,
A method for producing an epoxy derivative producing apparatus, wherein the solid polymer electrolyte unit electrolytically oxidizes the substrate to produce an epoxy derivative,
A production method, comprising: performing a reduction treatment on PtO ₂ to prepare PtO, and including the PtO in the anode catalyst layer.   The method according to claim 9, wherein the reducing treatment includes using a reducing agent.   The method according to claim 10, wherein the reducing agent is hydrazine. The production method according to claim 10, wherein the amount of the reducing agent used is less than 1 equivalent when the theoretical amount of PtO ₂ reduced to 100% Pt is 1 equivalent. The method according to claim 9, wherein the reducing treatment includes placing PtO ₂ in the presence of a reducing gas and at a predetermined temperature.   The method according to claim 13, wherein the temperature is lower than 50 ° C.

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