Recycling of catalyst coating films

Abstract

The present invention relates to a recycling process for recovering metal from a catalyst coating film comprising a fluorocarbon-containing ionomer film and at least one catalyst coating containing a metal. The present invention further relates to a process for producing a catalyst coating film from the metal recovered according to the recycling process of the present invention.

Description

[Technical Field]

[0001] The present invention relates to a recycling process for recovering metal from a catalyst coating film comprising a fluorocarbon-containing ionomer film and a metal-containing catalyst coating, and to a unit for carrying out the process. The present invention further relates to a process for producing a catalyst coating film from metal recovered according to the recycling process of the present invention. [Background technology]

[0002] Catalyst-coated membranes (CCMs) generally consist of a perfluorosulfonic acid (PFSA) polymer and a platinum group metal catalyst coated on the PFSA film using a PFSA binder. Both the platinum group metal catalyst and the PFSA polymer are valuable components that should be recycled in an efficient manner. In this regard, methods for separating the coating containing platinum group metals from the film, or for directly leaching the platinum group metals from the film by oxidizing an acidic medium, have been described in the art.

[0003] Numerous examples of the leaching of platinum group metals from such catalyst coatings can be found in publications such as International Publication No. 2006 / 073840(A1) and International Publication No. 2010 / 132156(A1). Several examples of the delamination of catalyst coatings from catalyst coatings by treatment with organic solvents can also be found in publications such as International Publication No. 2015 / 010793(A2), International Publication No. 2016 / 156815(A1), and European Patent No. 2036153(B1).

[0004] Several examples of combining these steps, first stripping the catalyst coating with an organic solvent, followed by leaching of the platinum group metals, are shown in European Patent No. 3000902(B1) and European Patent No. 3957759(A1). However, there is a need to provide a recycling process that can recover platinum group metals in better yield and also recover other components of the catalyst coating film, such as polymers.

[0005] Surprisingly, the process of the present invention has been found to significantly increase the recovery rate of metals in the catalyst coating film, particularly platinum group metals such as platinum, and to enable the recovery of polymers present in the catalyst coating on the film. [Overview of the project]

[0006] Therefore, the present invention relates to a recycling process for recovering metal from a catalyst coating film comprising a fluorocarbon-containing ionomer film and a catalyst coating comprising a polymer and a metal, wherein the metal is selected from the group consisting of platinum group metals, gold, silver, copper, nickel, cobalt, rare earth metals, gallium, indium, germanium, two or more alloys thereof, and two or more mixtures thereof, and the process is (i) To provide the catalyst coating film as one or more small pieces, (ii) One or more catalyst-coated film fragments provided in accordance with (i) are brought into contact with a first mixture containing water and a leaching agent, subjected to leaching conditions, and a mixture M1 is obtained containing metal dissolved in the first mixture and one or more catalyst-coated film fragments from which the metal has been depleted. (iii) Separating one or more catalyst coating film fragments obtained according to (ii) from the metal dissolved in the first mixture obtained according to (ii), (iv)(iii) The metal-depleted catalyst coating fragments obtained according to (iv)(iii) are brought into contact with a second mixture containing one or more C1-C8 alkyl alcohols, C1-C8 alkyl ketones, and C1-C8 alkyl esters, subjected to delamination conditions, and a mixture M2 is obtained, which contains at least a portion of the catalyst coating present in the second mixture and one or more film fragments from which at least a portion of the catalyst coating has been depleted. (v) Separating one or more film fragments from which at least a portion of the catalyst coating obtained according to (iv) has been depleted from at least a portion of the catalyst coating present in the second mixture obtained according to (iv), A2 M ≤A1 M A2 M However, the amount of metal in one or more film fragments that have been depleted of the catalyst coating obtained according to (iv) is A1 M However, the amount of metal obtained according to (ii) is the amount of metal in one or more catalyst coating film fragments that have been depleted, and this includes separation.

[0007] Accordingly, the present invention describes a novel and advantageous process in which a metal, such as platinum group metals, gold, silver, copper, nickel, cobalt, rare earth metals, gallium, indium, germanium, and their alloys or compounds, is first leached from the CCM, and then the remaining CCM, depleted of the metal, is subjected to a delamination treatment to obtain a film polymer and a residual coating containing a coating binder polymer and additives as conductivity-enhancing materials, such as carbon black.

[0008] Preferably, the polymer included in the catalyst coating is an ionomer, more preferably a fluorocarbon-containing ionomer, and more preferably a perfluorosulfonic acid (PFSA) ionomer.

[0009] Preferably, the catalyst coating further comprises one or more additives, one or more of which are more preferably carbon black.

[0010] Preferably, the catalyst coating further includes a substrate for supporting the metal, and more preferably, the porous substrate is a high surface area carrier.

[0011] In the context of the present invention, the metals included in the catalyst coating are selected from the group consisting of platinum, iridium, rhodium, palladium, osmium, ruthenium, gold, silver, copper, nickel, cobalt, lanthanum, scandium, yttrium, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, gallium, indium, germanium, two or more alloys thereof, and two or more mixtures thereof.

[0012] In the context of this invention, the term "metal" refers to a metal that exists as an element or as a compound such as an oxide.

[0013] Preferably, the metal included in the catalyst coating is selected from the group consisting of platinum, iridium, rhodium, osmium, palladium, ruthenium, gold, silver, copper, nickel, cobalt, lanthanum, scandium, yttrium, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, two or more alloys thereof, and two or more mixtures thereof. More preferably, the metal included in the catalyst coating is selected from the group consisting of platinum, iridium, rhodium, palladium, ruthenium, gold, silver, copper, nickel, cobalt, two or more alloys thereof, and two or more mixtures thereof.

[0014] Preferably, the metal contained in the catalyst coating is selected from the group consisting of platinum group metals, alloys thereof, and mixtures thereof, more preferably a platinum group metal, still more preferably platinum, iridium, alloys thereof, and mixtures thereof, and still more preferably platinum or iridium.

[0015] Therefore, preferably, the present invention relates to a recycling process for recovering a platinum group metal from a catalyst-coated film including a fluorocarbon-containing ionomer film and a catalyst coating including a polymer and a platinum group metal, the process comprising: (i) providing the catalyst-coated film as one or more small pieces; (ii) contacting the one or more small pieces of the catalyst-coated film provided according to (i) with a first mixture containing water and a leaching agent, subjecting to leaching conditions, and obtaining a mixture M1 including the platinum group metal dissolved in the first mixture and one or more small pieces of the catalyst-coated film depleted of the platinum group metal; (iii) separating the one or more small pieces of the catalyst-coated film depleted of the platinum group metal obtained according to (ii) from the platinum group metal dissolved in the first mixture obtained according to (ii); (iv) contacting the one or more small pieces of the catalyst-coated film depleted of the platinum group metal obtained according to (iii) with a second mixture including one or more of C1-C8 alkyl alcohols, C1-C8 alkyl ketones, and C1-C8 alkyl esters, subjecting to delamination conditions, and obtaining a mixture M2 including at least a part of the catalyst coating present in the second solution and one or more film pieces depleted of at least a part of the catalyst coating; (v) separating the one or more film pieces depleted of at least a part of the catalyst coating obtained according to (iv) from at least a part of the catalyst coating present in the second mixture obtained according to (iv), where M ≦A1 M where A2 M is the amount of the platinum group metal in one or more film pieces depleted of the catalyst coating obtained according to (iv), and A1 Mseparating, which is the amount of platinum group metal in one or more catalyst-coated film pieces in which the platinum group metal obtained according to (ii) has been depleted.

[0016] Therefore, preferably, the present invention relates to a recycling process for recovering platinum from a catalyst-coated film comprising a fluorocarbon-containing ionomer membrane and a catalyst coating containing a polymer and platinum, the process comprising: (i) providing the catalyst-coated film as one or more pieces; (ii) contacting the one or more catalyst-coated film pieces provided according to (i) with a first mixture comprising water and a leaching agent, subjecting the mixture to leaching conditions, and obtaining a mixture M1 comprising platinum dissolved in the first mixture and one or more catalyst-coated film pieces in which platinum has been depleted; (iii) separating the one or more catalyst-coated film pieces in which platinum has been depleted obtained according to (ii) from the platinum dissolved in the first mixture obtained according to (ii); (iv) contacting the one or more catalyst-coated film pieces in which platinum has been depleted obtained according to (iii) with a second mixture comprising one or more of C1-C8 alkyl alcohols, C1-C8 alkyl ketones, and C1-C8 alkyl esters, subjecting the mixture to delamination conditions, and obtaining a mixture M2 comprising at least a part of the catalyst coating present in the second solution and one or more film pieces in which at least a part of the catalyst coating has been depleted; (v) separating the one or more film pieces in which at least a part of the catalyst coating has been depleted obtained according to (iv) from at least a part of the catalyst coating present in the second mixture obtained according to (iv), where A2 M ≦A1 M and A2 M is the amount of platinum in one or more film pieces in which the catalyst coating obtained according to (iv) has been depleted, and A1 M is the amount of platinum in one or more catalyst-coated film pieces in which platinum has been depleted obtained according to (ii), separating.

[0017] Preferably, the present invention relates to a recycling process for recovering iridium from a catalyst coating film comprising a fluorocarbon-containing ionomer film and a catalyst coating comprising a polymer and iridium, wherein the process is (i) To provide the catalyst coating film as one or more small pieces, (ii) One or more catalyst-coated film fragments provided in accordance with (i) are brought into contact with a first mixture containing water and a leaching agent, subjected to leaching conditions, and a mixture M1 is obtained containing iridium dissolved in the first mixture and one or more catalyst-coated film fragments from which the iridium has been depleted. (iii) Separating one or more iridium-depleted catalyst coating fragments obtained according to (ii) from the iridium dissolved in the first mixture obtained according to (ii), (iv)(iii) One or more iridium-depleted catalyst coating fragments obtained according to (iv)(iii) are brought into contact with a second mixture containing one or more C1-C8 alkyl alcohols, C1-C8 alkyl ketones, and C1-C8 alkyl esters, subjected to delamination conditions, and a mixture M2 is obtained containing at least a portion of the catalyst coating present in the second solution and one or more film fragments from which at least a portion of the catalyst coating has been depleted. (v) Separating one or more film fragments from which at least a portion of the catalyst coating obtained according to (iv) has been depleted from at least a portion of the catalyst coating present in the second mixture obtained according to (iv), A2 M ≤A1 M A2 M However, the amount of iridium in one or more film fragments that have been depleted of the catalyst coating obtained according to (iv) is A1 M However, the iridium obtained according to (ii) is the amount of iridium in one or more catalyst coating film fragments that have been depleted, and this includes separation.

[0018] In the context of the present invention, it is preferable that the fluorocarbon-containing ionomer film is coated on both sides, with at least one side coated with a catalyst coating. In fact, the other side may be coated with a catalyst coating comprising a polymer and a platinum group metal different from the platinum group metal contained in the other catalyst coating. As a result of the above possibilities, two or more platinum group metals can be recovered in steps (ii) and (iii) of the present invention. For example, platinum and iridium can be recovered in the step if they are present in the catalyst coating.

[0019] In the context of the present invention, preferably, the fluorocarbon-containing ionomer film is a perfluorosulfonic acid (PFSA) ionomer film.

[0020] Preferably, (i) is (i.1) To provide a catalyst coating assembly including a catalyst coating film and a sub-gasket, (i.2) Cutting the catalyst coating assembly into small pieces, (i.3) The fragments obtained according to (i.2) are sorted into at least two different flows to obtain a first flow containing one or more fragments of the catalyst coating film, wherein the one or more fragments have depleted sub-gaskets, and a second flow containing sub-gaskets.

[0021] Step (i.1) is, To provide a membrane electrode assembly comprising a catalyst coating film assembly, one or more gaskets, and one or more gas diffusion layers, wherein one or more gaskets are located on one or more gas diffusion layers, and one or more gas diffusion layers are located on the catalyst coating film assembly. The method may include removing one or more gaskets, followed by removing one or more gas diffusion layers, to obtain a catalyst coating assembly, wherein the assembly includes a catalyst coating and sub-gaskets.

[0022] Preferably, the cutting according to (i.2) is carried out using a cutting device, which is more preferably a rotary knife, a punching tool (e.g., a rotary punch), a guillotine, a four-axis shredder, a one-axis shredder, a two-axis shredder, or a rotor shear, more preferably a rotary knife or a punching tool (e.g., a rotary punch).

[0023] Preferably, the average surface area of ​​the small pieces obtained according to (i.2) is 0.1 to 300 cm². 2 The range, more preferably 0.5 to 25 cm 2 The range, more preferably 0.9 to 5 cm 2 It is within the range of [the specified range].

[0024] Preferably, one or more pieces of the catalyst coating film obtained according to (i.3) do not contain a sub-gasket.

[0025] Preferably, the sorting according to (i.3) is performed manually or automatically.

[0026] Preferably, the sorting according to (i.3) is optical sorting, more preferably the optical sorting is hyperspectral, UV, or VIS sorting or infrared sorting, more preferably near-infrared sorting or mid-infrared sorting. The material may be irradiated with microwave radiation, and sorting may be carried out according to the heat absorbed by particles of different compositions.

[0027] Preferably, the leaching agent included in the first mixture used according to (ii) is selected from the group consisting of a Bronsted acid, a Bronsted base, or a complexing agent.

[0028] Preferred acids include hydrochloric acid, sulfuric acid, nitric acid, or organic acids such as methanesulfonic acid, formic acid, and citric acid.

[0029] Regarding the base, alkali metal hydroxides such as potassium hydroxide and sodium hydroxide, alkaline earth metal hydroxides, alkali metal carbonates, alkaline earth metal carbonates, or alkaline earth metal oxides are preferred.

[0030] With regard to the complexing agent, it is preferably a compound containing one or more of ammonia, an amino group, and a thio group, a crown ether, an amino derivative crown ether, a thio derivative crown ether, a cyclophane, an amino derivative cyclophane, and a thio derivative cyclophane.

[0031] Preferably, the leaching agent contained in the first mixture used according to (ii) is a Bronsted acid or a Bronsted base, more preferably a Bronsted acid.

[0032] Preferably, the leaching agent contained in the first mixture used according to (ii) is hydrochloric acid.

[0033] Preferably, the first mixture consists of a leachate and water, especially when the leachate is nitric acid.

[0034] Preferably, the first mixture used according to (ii) further comprises an oxidizing agent, the oxidizing agent being more preferably one or more of chlorates, perchlorates, hypochlorites, chlorine, bromine, ozone, oxygen, hydrogen peroxide, peroxosulfates, chromates, permanganates, ironates, and Fenton's reagent (hydrogen peroxide and ferrous chlorate), more preferably one or more of chlorates, chlorine, ozone, oxygen, and hydrogen peroxide, more preferably a chlorate such as chlorine (Cl2) or an alkali metal chlorate, more preferably sodium chlorate.

[0035] Preferably, the first mixture comprises a leaching agent, an oxidizing agent, and water, and more preferably consists of these.

[0036] Preferably, the oxidizing agent is used in stoichiometric excess relative to the metal to be recovered.

[0037] Preferably, when the oxidizing agents are sodium chlorate and metallic platinum, the molar ratio of NaClO3:Pt is in the range of 2:1 to 10:1, more preferably in the range of 4:1 to 8:1. In the context of the present invention, the metal content can be readily determined by ICP or XRF according to the knowledge of those skilled in the art.

[0038] Preferably, the solid content in the first mixture is in the range of 1 to 30% by weight, more preferably 1 to 20% by weight, based on the weight of the first mixture.

[0039] Preferably, the first mixture used according to (ii) contains at least 10% by weight, more preferably 10-80% by weight, more preferably 20-50% by weight, and more preferably 26-36% by weight of the leaching agent, based on the weight of the first mixture.

[0040] Preferably, the first mixture is an aqueous solution.

[0041] Preferably, one or more catalyst-coated film fragments provided according to (i) are brought into contact with a first mixture containing water and a leaching agent, and subjected to leaching conditions according to (ii). The process includes introducing one or more catalyst-coated film fragments provided in accordance with (i) into a reactor unit containing a first mixture, mixing them, and heating the resulting mixture to a temperature in the range of 15 to 200°C, more preferably 20 to 150°C, and more preferably 60 to 100°C.

[0042] Preferably, heating is carried out until the vapor pressure of the first aqueous mixture equals atmospheric pressure. At higher temperatures, the reaction is carried out under pressure. Pressurization may also be advantageous in the case of gaseous reagents, such as ammonia, chlorine, or ozone. Pressurization increases the partial pressure in the gas phase, thereby improving the solubility and reactivity of these gaseous reagents.

[0043] Preferably, the reactor unit does not include a pulverizer or granulator.

[0044] When pressure is applied, the reactor unit used according to (ii) is preferably a pressure reactor unit, more preferably a pressure in the reactor unit in the range of 0.5 to 100 barg, more preferably 5 to 200 barg.

[0045] Alternatively, if the reaction does not take place under pressure, the reactor unit is a stirred-vessel reactor. In particular, although we do not wish to be bound by any theory, stirring generally improves the mixing of the solid, liquid, and gaseous components of a mixture.

[0046] Preferably, in the context of the present invention, heating according to (ii) is carried out under reflux.

[0047] Preferably, heating according to (ii) is carried out for a duration ranging from 0.1 to 50 hours, more preferably from 0.1 to 24 hours, and more preferably from 0.5 to 4 hours. In the context of the present invention, it should be noted that, as is known to those skilled in the art, the duration may vary depending on the size and type of the container. The duration referred to herein is the duration of heating at a given temperature (not the duration of heating or cooling to reach a given temperature).

[0048] For reactions that operate continuously, these times refer to the average residence time in a continuously operating reactor unit (one reactor). If the reactor unit includes at least two reactors in series, these times correspond to the average residence time in each reactor of the reactor cascade.

[0049] Preferably, separation according to (iii) includes passing the M1 obtained according to (ii) through a solid-liquid separation unit, the solid-liquid separation unit being more preferably a sieve or filter, more preferably a sieve.

[0050] Preferably, separation according to (iii) further includes rinsing one or more catalyst coating film fragments on the solid-liquid separation unit with a leaching agent and / or water, more preferably deionized water.

[0051] In the context of the present invention, it should be noted that the rinsing step may be advantageous for removing any potential portions of the first mixture that may remain on the film fragments. This rinsing also ensures that all valuable metals dissolved in the first liquid are recovered.

[0052] Preferably, the metal dissolved in the first mixture obtained according to (iii) is subjected to one or more subsequent processes, such as a wet metallurgy process, to recover the metal as either a pure metal or a metal salt, or a mixture of metal or metal salts.

[0053] Preferably, A1 M <A0 M A1 M This is the amount of metal in one or more catalyst coating film small pieces that have been depleted according to (ii), and A0 M is the amount of metal in the catalyst coating film provided according to (i).

[0054] Preferably, one or more metal-depleted catalyst coating fragments obtained according to (ii) have a reduced amount of metal in the range of 50-100% by weight, more preferably 80-100% by weight, more preferably 90-100% by weight, more preferably 95-100% by weight, and more preferably 98-100% by weight, compared to the catalyst coating provided according to (i).

[0055] Preferably, the second mixture used in (iv) comprises a C1-C8 alkyl alcohol, more preferably a C3-C6 alkyl alcohol.

[0056] Preferably, the second mixture used in (iv) is an aqueous mixture, and more preferably, the second mixture used in (iv) consists of a C1-C8 alkyl alcohol, more preferably a C3-C6 alkyl alcohol, and water.

[0057] In the context of the present invention, the second mixture can at least partially dissolve or swell the coating by weakening it, or eliminate adhesion between the coating and the film.

[0058] Preferably, the C1-C8 alkyl alcohol is one or more of methanol, ethanol, isopropanol, n-propanol, butan-2-ol, isobutanol, and n-butanol, more preferably isopropanol.

[0059] Preferably, the weight ratio of one or more C1-C8 alkyl alcohols, C1-C8 alkyl ketones, and C1-C8 alkyl esters to water in the second mixture used in step (iv) is in the range of 0.1:1 to 1:0, more preferably in the range of 0.1:1 to 1:0.1, and more preferably in the range of 0.2:1 to 1:0.2.

[0060] For compounds containing more than three carbon atoms, the upper limit of the water content is determined by the miscibility of the water in the compound.

[0061] Preferably, one or more metal-depleted catalyst coating film fragments obtained according to (iii) are brought into contact with a second mixture containing one or more C1-C8 alkyl alcohols, C1-C8 alkyl ketones, and C1-C8 alkyl esters, and subjected to delamination conditions according to (iv). The process includes introducing one or more metal-depleted catalyst coating film fragments obtained in accordance with (iii) into a container containing a second mixture, mixing, more preferably shaking, and optionally applying shear force to one or more film fragments by stirring, using a fluid jet, scraping, or brushing.

[0062] Preferably, the separation by (v) involves removing one or more catalyst-coated film fragments from the second mixture.

[0063] Preferably, separation according to (v) includes passing the M2 obtained according to (iv) through a solid-liquid separation unit, the solid-liquid separation unit being more preferably a sieve or filter or a centrifuge or decanter-type centrifuge, more preferably a sieve.

[0064] Optionally, the process (v) after, - Rinse one or more of the obtained catalyst-coated film fragments with water, preferably deionized water, -The process further includes passing one or more rinsed catalyst-coated film fragments suspended in water through a stirring unit, more preferably a blade granulator or rotor stator, to a subsequent delamination step to obtain at least a portion of the remaining catalyst coating and one or more film fragments from which at least a portion of the catalyst coating has been depleted.

[0065] Preferably, separating according to (v) is The method further comprises rinsing one or more catalyst-coated film fragments with a third mixture containing one or more C1-C8 alkyl alcohols, C1-C8 alkyl ketones, and C1-C8 alkyl esters.

[0066] Preferably, the third mixture used for rinsing according to (v) is the same as the second mixture used in (iv). The third mixture is preferably an aqueous mixture, more preferably an aqueous solution of a C1-C8 alkyl alcohol and water, and more preferably an aqueous solution of isopropanol and water.

[0067] Preferably, this process further comprises rinsing one or more catalyst-coated film fragments with a third mixture containing a C1-C8 alkyl alcohol, and subsequently rinsing the one or more catalyst-coated film fragments with water, more preferably deionized water.

[0068] Preferably, the process of the present invention is (vi) Further comprising drying one or more film fragments from which at least a portion of the catalyst coating obtained according to (v) has been depleted.

[0069] Preferably, drying according to (vi) is carried out at a temperature of 25 to 250°C, depending on the reagent used, as is well known to those skilled in the art. Drying can be carried out under reduced pressure.

[0070] Preferably, the platinum group metal content in one or more film fragments obtained according to (v), more preferably (iv), is reduced by 80-100%, more preferably 90-100%, more preferably 95-100%, and more preferably 98-100% compared to the platinum group metal content of the catalyst coating film.

[0071] Preferably, one or more dried film fragments obtained according to (vi) are introduced into a container having an aqueous mixture having a pH in the range of 0 to 6.5, more preferably 1 to 3, to obtain a mixture. The process further includes heating the mixture to a temperature in the range of 20 to 100°C. This step is thought to restore the proton conductivity of the film.

[0072] Preferably, the process is (vii)(v) Further includes recovering the polymer contained in at least a portion of the catalyst coating obtained according to (vii)(v).

[0073] Preferably, the polymer is recovered according to (vii). (v) The method involves passing at least a portion of the catalyst coating present in the second mixture obtained according to (v) through a separation unit to obtain a polymer, more preferably the polymer being an ionomer, more preferably a fluorine-containing ionomer.

[0074] Preferably, the separation unit is a filter, a centrifuge, or a decanter.

[0075] The present invention further comprises a unit for carrying out the process according to the present invention, A reactor unit for subjecting one or more catalyst-coated film fragments to leaching conditions together with a first mixture, A means for introducing the catalyst coating film as one or more small pieces, Means for introducing the first mixture, Means for removing M1 from the reactor unit, Separation unit and A means for introducing M1 into the separation unit, A container for subjecting one or more catalyst coating film fragments with depleted metals to delamination conditions, A means for introducing one or more catalyst coating film fragments with depleted metals into a container, Means for introducing a second mixture into a container, Means for removing M2 from the container, The present invention relates to a unit comprising means for separating at least a portion of the catalyst coating present in a second mixture from one or more film fragments from which at least a portion of the catalyst coating has been depleted.

[0076] In the context of the present invention, it should be noted that a reactor unit for subjecting one or more catalyst-coated film fragments to leaching conditions together with a first mixture is different from a container for subjecting one or more metal-depleted catalyst-coated film fragments to delamination conditions. Similarly, the means used in the reactor unit are different from the means used in the container.

[0077] Preferably, the reactor unit does not include a pulverizer or granulator.

[0078] The present invention further comprises a process for producing a catalyst coating film, preferably for a fuel cell. The present invention relates to a process that includes using a metal obtained according to a recycling process, more preferably a platinum group metal, more preferably platinum or iridium.

[0079] In the context of the present invention, since the process avoids high-temperature treatment, residual polymers can be recovered and used in different applications, namely, applications including the manufacture of new fuel cell or electrolytic cell membranes for chlor-alkali electrolysis, or the manufacture of breathable waterproof coatings.

[0080] The present invention further comprises a process for producing a catalyst coating film, preferably for a fuel cell. The present invention relates to a process that includes using a polymer, more preferably an ionomer, obtained according to a recycling process according to the present invention. The polymer obtained according to a recycling process according to the present invention can be used as a mixture with an initial polymer material.

[0081] The present invention further comprises a process for producing a catalyst coating film, preferably for a fuel cell. The present invention relates to a process that includes using one or more membrane fragments obtained according to a recycling process.

[0082] The present invention further comprises a process for producing a catalyst coating film, preferably for a fuel cell. The following - A metal obtained according to the recycling process according to the present invention, preferably a platinum group metal, more preferably platinum or iridium, - A polymer obtained according to the recycling process of the present invention, preferably an ionomer, and -The present invention relates to a process that includes using one or more membrane fragments obtained according to a recycling process according to the present invention.

[0083] The present invention further relates to a process for producing a catalyst coating film for fuel cells, (a) To perform a process according to the present invention to obtain a metal, preferably a platinum group metal, more preferably platinum or iridium, a polymer, preferably an ionomer, and one or more film fragments, (b) relating to a process to obtain a catalyst coating film for a fuel cell, comprising using one or more of the metals, polymers and film fragments obtained in accordance with (a).

[0084] The present invention further relates to the use of one or more of the following for producing catalyst coating films for fuel cells: metals obtained according to the present invention, preferably platinum group metals, more preferably platinum or iridium; polymers obtained according to the present invention, preferably ionomers; and one or more film fragments obtained according to the present invention. [Modes for carrying out the invention]

[0085] The present invention is further illustrated by the following set of embodiments, and by combinations of embodiments arising from dependencies and reverse references as shown. In particular, it should be noted that in each instance where the scope of an embodiment is referred to, for example, in the context of terms such as “any one process of Embodiments 1 to 3,” all embodiments within this scope are expressly disclosed to those skilled in the art, i.e., the expression of this term is understood to those skilled in the art to be synonymous with “any one process of Embodiments 1, 2, and 3.” Furthermore, it should be clearly noted that the following set of embodiments represents a suitably structured portion of a general description covering preferred aspects of the present invention, and therefore suitably supports, but does not represent, the claims of the present invention. 1. A recycling process for recovering metal from a catalyst coating film comprising a fluorocarbon-containing ionomer film and a catalyst coating containing a polymer and a metal, wherein the metal is selected from the group consisting of platinum group metals, gold, silver, copper, nickel, cobalt, rare earth metals, gallium, indium, germanium, two or more alloys thereof, and two or more mixtures thereof, and the process is: (i) To provide the catalyst coating film as one or more small pieces, (ii) One or more catalyst-coated film fragments provided in accordance with (i) are brought into contact with a first mixture containing water and a leaching agent, subjected to leaching conditions, and a mixture M1 is obtained containing metal dissolved in the first mixture and one or more catalyst-coated film fragments from which the metal has been depleted. (iii) Separating one or more catalyst coating film fragments obtained according to (ii) from the metal dissolved in the first mixture obtained according to (ii), (iv)(iii) The metal-depleted catalyst coating fragments obtained according to (iv)(iii) are brought into contact with a second mixture containing one or more C1-C8 alkyl alcohols, C1-C8 alkyl ketones, and C1-C8 alkyl esters, subjected to delamination conditions, and a mixture M2 is obtained, which contains at least a portion of the catalyst coating present in the second mixture and one or more film fragments from which at least a portion of the catalyst coating has been depleted. (v) Separating one or more film fragments from which at least a portion of the catalyst coating obtained according to (iv) has been depleted from at least a portion of the catalyst coating present in the second mixture obtained according to (iv), A2 M ≤A1 M A2 M However, the amount of metal in one or more film fragments that have been depleted of the catalyst coating obtained according to (iv) is A1 M However, the process includes separating the metal obtained according to (ii) the amount of metal in one or more catalyst coating film fragments that have been depleted. 2. The process according to Embodiment 1, wherein the polymer contained in the catalyst coating is an ionomer, more preferably a fluorocarbon-containing ionomer, and more preferably a perfluorosulfonic acid (PFSA) ionomer. 3. The process according to Embodiment 1 or 2, wherein the metal included in the catalyst coating is selected from the group consisting of platinum, iridium, rhodium, osmium, palladium, ruthenium, gold, silver, copper, nickel, cobalt, lanthanum, scandium, yttrium, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, two or more alloys thereof, and two or more mixtures thereof; preferably, the metal included in the catalyst coating is selected from the group consisting of platinum, iridium, rhodium, palladium, ruthenium, gold, silver, copper, nickel, cobalt, two or more alloys thereof, and two or more mixtures thereof; more preferably, the metal included in the catalyst coating is selected from the group consisting of platinum, iridium, rhodium, palladium, ruthenium, gold, silver, copper, nickel, cobalt, two or more alloys thereof, and two or more mixtures thereof. 4. The process according to Embodiment 3, wherein the metal contained in the catalyst coating is selected from the group consisting of platinum group metals, their alloys, and mixtures thereof, more preferably a platinum group metal, more preferably platinum, iridium, their alloys, and mixtures thereof, and more preferably platinum or iridium. 5. The process according to any one of Embodiments 1 to 4, wherein both sides of the fluorocarbon-containing ionomer film are coated, and at least one side is coated with a catalyst coating. 6. The process according to any one of Embodiments 1 to 5, wherein the fluorocarbon-containing ionomer film is a perfluorosulfonic acid (PFSA) ionomer film. 7. (i) is, (i.1) To provide a catalyst coating assembly including a catalyst coating film and a sub-gasket, (i.2) Cutting the catalyst coating assembly into small pieces, The process according to any one of Embodiments 1 to 6, comprising sorting the fragments obtained according to (i.3)(i.2) into at least two different flows to obtain a first flow containing one or more fragments of the catalyst coating film, wherein the one or more fragments have depleted subgaskets, and a second flow containing subgaskets. The leaching agent contained in the first mixture used in accordance with 8.(ii) is selected from the group consisting of a Bronsted acid, a Bronsted base, or a complexing agent. The acid is preferably hydrochloric acid, sulfuric acid, nitric acid, or an organic acid. The base is preferably an alkali metal hydroxide, an alkaline earth metal hydroxide, an alkali metal carbonate, an alkaline earth metal carbonate, or an alkaline earth metal oxide. The complexing agent is preferably a compound containing one or more of ammonia, an amino group, and a thio group, a crown ether, an amino derivative crown ether, a thio derivative crown ether, a cyclophane, an amino derivative cyclophane, and a thio derivative cyclophane. The process according to any one of Embodiments 1 to 7, preferably the leaching agent contained in the first mixture used according to (ii) is a Bronsted acid or a Bronsted base, more preferably a Bronsted acid. The process according to any one of Embodiments 1 to 8, wherein the first mixture used in accordance with 9.(ii) further comprises an oxidizing agent, the oxidizing agent preferably one or more of chlorates, perchlorates, hypochlorites, chlorine, bromine, ozone, oxygen, hydrogen peroxide, peroxosulfates, chromates, permanganates, ferrates, and Fenton's reagent (hydrogen peroxide and ferrous phosphate), preferably one or more of chlorates, chlorine, ozone, oxygen, and hydrogen peroxide, and more preferably chlorine (Cl2) or a chlorate. The process according to any one of Embodiments 1 to 9, wherein the first mixture used in accordance with 10.(ii) comprises at least 10% by weight, preferably 10 to 80% by weight, more preferably 20 to 50% by weight, and more preferably 26 to 36% by weight of the first mixture, in the form of a leaching agent. 11. One or more catalyst-coated film fragments provided in accordance with (i) are brought into contact with a first mixture containing water and a leaching agent, and subjected to leaching conditions in accordance with (ii). The process according to any one of Embodiments 1 to 10, comprising introducing one or more catalyst-coated film fragments provided in accordance with (i) into a reactor unit containing a first mixture, mixing them, and heating the resulting mixture to a temperature in the range of 15 to 200°C, preferably in the range of 20 to 150°C, more preferably in the range of 60 to 100°C. The process according to Embodiment 11, wherein heating in accordance with 12.(ii) is performed under reflux. The process according to Embodiment 11 or 12, wherein heating in accordance with 13.(ii) is carried out for a duration ranging from 0.1 to 50 hours, preferably from 0.1 to 24 hours, and more preferably from 0.5 to 4 hours. The process according to any one of Embodiments 1 to 13, wherein the separation according to (iii) comprises passing the M1 obtained according to (ii) through a solid-liquid separation unit, the solid-liquid separation unit being preferably a sieve or filter, more preferably a sieve. The process according to Embodiment 14, further comprising rinsing one or more catalyst coating film fragments on the solid-liquid separation unit with water, preferably deionized water, in accordance with 15.(iii). The process according to any one of Embodiments 1 to 15, wherein the second mixture used in 16.(iv) comprises a C1-C8 alkyl alcohol, preferably a C3-C6 alkyl alcohol. 17. The process according to any one of Embodiments 1 to 16, wherein the C1-C8 alkyl alcohol is one or more of methanol, ethanol, isopropanol, n-propanol, butan-2-ol, isobutanol, and n-butanol, preferably isopropanol. The process according to any one of Embodiments 1 to 17, wherein the weight ratio of one or more C1-C8 alkyl alcohols, C1-C8 alkyl ketones and C1-C8 alkyl esters to water in the second mixture used in 18.(iv) is in the range of 0.1:1 to 1:0, preferably in the range of 0.1:1 to 1:0.1, and more preferably in the range of 0.2:1 to 1:0.2. 19. Contacting one or more metal-depleted catalyst coating film fragments obtained according to (iii) with a second mixture containing one or more C1-C8 alkyl alcohols, C1-C8 alkyl ketones, and C1-C8 alkyl esters, and subjecting them to delamination conditions according to (iv), The process according to any one of Embodiments 1 to 18, comprising introducing one or more metal-depleted catalyst coating film fragments obtained according to (iii) into a container containing a second mixture, mixing, preferably shaking, and optionally applying a shear force to one or more film fragments by stirring, using a fluid jet, scraping, or brushing. The process according to any one of Embodiments 1 to 19, wherein separation according to 20.(v) includes removing one or more catalyst coating fragments from the second mixture. The process according to any one of Embodiments 1 to 20, further comprising rinsing one or more catalyst-coated film fragments with a third mixture comprising one or more C1-C8 alkyl alcohols, C1-C8 alkyl ketones, and C1-C8 alkyl esters, in accordance with 21.(v). twenty two. The process according to any one of Embodiments 1 to 21, further comprising drying one or more film fragments from which at least a portion of the catalyst coating obtained according to (vi)(v) has been depleted. 23. (vi) The dried film fragments obtained in accordance with (vi) are introduced into a container having an aqueous mixture having a pH in the range of 0 to 6.5, preferably 1 to 3, to obtain the mixture. The process according to Embodiment 22, further comprising heating the mixture to a temperature in the range of 20 to 100°C. twenty four. The process according to any one of Embodiments 1 to 23, further comprising recovering the polymer contained in at least a portion of the catalyst coating obtained according to (vii)(v). 25.(iv) The polymer can be recovered according to the following procedure. The process according to Embodiment 24, comprising passing at least a portion of the catalyst coating present in the second mixture obtained according to (v) through a separation unit to obtain a polymer, preferably a polymer which is an ionomer, more preferably a fluorine-containing ionomer. 26. A unit for carrying out the process described in any one of Embodiments 1 to 25, A reactor unit for subjecting one or more catalyst-coated film fragments to leaching conditions together with a first mixture, A means for introducing the catalyst coating film as one or more small pieces, Means for introducing the first mixture, Means for removing M1 from the reactor unit, Separation unit and A means for introducing M1 into the separation unit, A container for subjecting one or more catalyst coating film fragments with depleted metals to delamination conditions, A means for introducing one or more catalyst coating film fragments with depleted metals into a container, Means for introducing a second mixture into a container, Means for removing M2 from the container, A unit comprising means for separating at least a portion of the catalyst coating present in a second mixture from one or more film fragments from which at least a portion of the catalyst coating has been depleted. 27. A process for producing a catalyst coating film for fuel cells, A process comprising using a metal obtained according to any one of the recycling processes described in Embodiments 1 to 25, preferably a platinum group metal, more preferably platinum or iridium. 28. A process for producing a catalyst coating film for fuel cells, A process comprising using a polymer, preferably an ionomer, obtained according to any one of the recycling processes described in Embodiments 1 to 25. 29. A process for producing a catalyst coating film for fuel cells, A process comprising using one or more membrane fragments obtained according to the recycling process described in any one of Embodiments 1 to 25. 30. A process for producing a catalyst coating film for fuel cells, - A metal obtained according to the recycling process described in any one of Embodiments 1 to 25, preferably a platinum group metal, more preferably platinum or iridium, - A polymer, preferably an ionomer, obtained according to the recycling process described in any one of Embodiments 1 to 25, and A process comprising using one or more membrane fragments obtained according to the recycling process described in any one of Embodiments 1 to 25. 31. A process for producing a catalyst coating film for fuel cells, (a) Performing the process described in any one of Embodiments 1 to 25 to obtain a metal, preferably a platinum group metal, more preferably platinum or iridium, a polymer, preferably an ionomer, and one or more film fragments, (b) A process comprising using one or more of the metal, polymer and one or more film fragments obtained according to (a) in order to obtain a catalyst coating film for a fuel cell. 32. Use of one or more of the following for producing a catalyst coating film for a fuel cell: a metal obtained according to any one of Embodiments 1 to 25, preferably a platinum group metal, more preferably platinum or iridium; a polymer obtained according to any one of Embodiments 1 to 25, preferably an ionomer; and one or more film fragments obtained according to any one of Embodiments 1 to 25.

[0086] It should be clearly noted that the above-described set of embodiments represents a well-structured portion of a general description relating to preferred embodiments of the present invention, and therefore adequately supports, but does not represent, the claims of the present invention.

[0087] In the context of this invention, when the term "film" is used, it refers to a solid film, as opposed to a dissolved or diluted state. Due to the action of the second mixture, the film can absorb a considerable amount of the liquid or a portion of the liquid through this swelling. However, the shape of the film does not change much, except for its dimensions. In this respect, the behavior of coating polymers is quite different, as they partially dissolve and swell to the point where the coating shape is lost and a mass of swollen polymer is formed. This different behavior is a result of either a higher degree of polymerization and / or crosslinking in film polymers compared to coating polymers.

[0088] In the context of this invention, the term "platinum group metals" is well known in the art and refers to metals selected from the group consisting of platinum, iridium, palladium, rhodium, osmium, and ruthenium.

[0089] In the context of the present invention, the term "rare earth metal" is well known in the art and refers to a metal selected from the group consisting of lanthanum, scandium, yttrium, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium.

[0090] In the context of this invention, the term “one or pieces” referring to the film / coating film does not refer to any powder, as disclosed in prior art such as International Publication No. 2010 / 132156(A2). In fact, in International Publication No. 2010 / 132156(A2), the film is pulverized, which is disadvantageous because it is not possible to later separate the small film particles from the coating polymer. The advantage of retaining the film as pieces (rather than as powder) is that they can be more easily separated from the coating polymer gel. Another disadvantage of the process in International Publication No. 2010 / 132156(A2) is that even if the two leaching steps are performed sequentially, it is not possible to recover a portion of the catalyst coating and separate it from the film pieces, as in step (iv) of this invention. At best, it would be possible to recover even more platinum group metals.

[0091] In the context of the present invention, the term “exfoliation conditions” refers to the conditions necessary for exfoliating a given coated sample in a solvent, i.e., the conditions necessary to remove at least a portion of the coating. Such conditions may include simply immersing the sample in the solvent, or mixing, preferably shaking, and optionally applying shear force to the sample by stirring, preferably using a fluid jet, scraping, or brushing.

[0092] In the context of the present invention, the phrase "X is one or more of A, B, and C" (where X is a given feature, and each of A, B, and C represents a specific realization of that feature) should be understood as disclosing that X is either A, or B, or C, or A and B, or A and C, or B and C, or A and B and C. In this regard, those skilled in the art should note that the above abstract terms can be translated into concrete examples. For example, X may be a chemical element, and A, B, and C may be specific elements such as Li, Na, and K, or X may be a temperature, and A, B, and C may be specific temperatures such as 10°C, 20°C, and 30°C. In this regard, those skilled in the art should further note that the above terms may be extended to less specific descriptions of the feature (for example, "X is one or more of A and B" discloses that X is either A, B, or A and B), or to more specific descriptions of the feature (for example, "X is one or more of A, B, C, and D" discloses that X is either A, B, C, or D, or A and B, or A and C, or A and D, or B and C, or B and D, or C and D, or A and B and C, or B and C and D, or A and B and C and D).

[0093] The present invention will be further explained by the following examples. [Examples]

[0094] Composition of the catalyst coating film (CCM) used in the examples: In the following examples, a carbon capture device (CCM) consisting of a perfluorosulfonic acid (PFSA) polymer film* (Nafion® PFSA film, commercially available and purchased from Chemors) coated on both sides with a Pt-containing carbon-based catalyst, with perfluorosulfonic acid (PFSA) polymer as the binder, was used, and carbon black was used as an additive. The film thickness was 10 micrometers, and the coating film thickness was 25 micrometers, meaning the total thickness of the coatings on both sides was 15 micrometers.

[0095] The catalyst coating film is composed of 45.5% by weight of F, 0.8% by weight of S, and 10.9% by weight of Pt, with a surface specific weight of 4.2 mg / cm³. 2 That was the case.

[0096] * The perfluorosulfonic acid (PFSA) polymer (ionomer) film was produced by free radical-initiated copolymerization of perfluorovinyl ethersulfonyl fluoride comonomer and tetrafluoroethylene (TFE), giving a poly(tetrafluoroethylene) skeleton with perfluoroether pendant side chains terminated by sulfonic acid groups.

[0097] analysis: 1. Determination of F content Elemental analysis of fluorine was performed in accordance with DIN EN 14582:2016-12 for sample preparation for total fluorine content measurement. The detection method was ion-selective electrode measurement.

[0098] 2. Determination of S content Sulfur was measured by catalytic combustion of the sample in an inert gas / oxygen atmosphere, which converted the sulfur into a mixture of SO2 and SO3. The formed SO3 was then reduced to SO2 with copper granules. After drying and separating the combustion gases, sulfur was detected and quantified as SO2 by thermal conductivity or IR spectrometer.

[0099] 3. Determination of platinum group metal content The platinum group metals, particularly Pt, in the obtained sample solution were determined by optical emission spectroscopy using an inductively coupled plasma (ICP-OES). Subsequently, Pt was determined using ICP-OES Agilent 5100 SVDV.

[0100] 4. Calculation of Pt leaching efficiency The Pt leaching efficiency is calculated using the following formula:

[0101]

number

[0102] Example 1: Recycling process according to the present invention - Platinum group metal leaching and subsequent delamination 1. Cutting and sorting A catalyst coating film attached to a sub-gasket was prepared. Generally, the catalyst coating film is attached to the sub-gasket with a welded rim, as can be seen in Figure 1. This assembly was subjected to a cutting process to obtain small pieces of approximately 20 × 20 mm. This process was carried out manually using a cutting device, i.e., scissors. The obtained pieces were manually sorted to separate the pieces of the sub-gasket from the pieces of the catalyst coating film and the pieces of the welded rim.

[0103] 2.Platinum group metal leaching 100 g of an acidic aqueous solution containing hydrochloric acid (HCl: 33 wt% based on the weight of the solution + water: 67 wt% based on the weight of the solution) was introduced into a 250 mL round-bottom flask equipped with a stirrer and reflux condenser. 0.25 g of sodium chlorate was added to this solution as an oxidizing agent. Next, 2.0844 g of CCM was cut into pieces of approximately 20 × 20 mm obtained according to 1 and added to the flask. The suspension was placed in an oil bath and heated to 80°C for 35 minutes with stirring. The suspension was maintained at 80°C for a total of 9.5 hours, and additional portions of 0.25 g of sodium chlorate were added after 3.5 hours and 4.5 hours to obtain a total amount of added sodium chlorate of 0.75 g (corresponding to a molar ratio of approximately 6:1 NaClO3:Pt). The Pt leaching efficiency after 4.5 hours, obtained from the Pt content of the leached membrane pieces measured by XRF using the formula shown in Analysis 4 above, was 98.8%. After leaching, the membrane fragments were separated by sieving. The membrane fragments were further rinsed with deionized water. Samples of the membrane fragments were taken and analyzed for residual Pt by ICP-OES (see Analysis 3 above in this specification). The residual Pt content on the membrane fragments was 0.09% by weight based on the weight of the sample tested.

[0104] The Pt leaching efficiency was calculated according to the formula disclosed in Analysis 4. In this specification, it was 99.3%.

[0105] 3. Delamination Subsequently, the separated and washed membrane fragments (1.2915 g) obtained according to step 2 were suspended in a mixture of isopropanol and water (30 wt% isopropanol + 70 wt% water). This suspension was shaken in a shaker at room temperature (approximately 20°C) for 15 minutes. The membrane fragments were removed from the suspension. Any adhering coating residue was removed by gently scraping with a spatula. Finally, each membrane fragment was rinsed first with the isopropanol / water mixture and then with pure water. The rinsed membrane fragments were suspended with clamps and dried in ambient air. The resulting solvent containing the separated coating was centrifuged at 5000 rpm for 30 minutes (using a Universal 320 R centrifuge from Andreas Hettich GmbH & Co.KG) to obtain two phases: a clear solvent phase and a gel-like precipitate. The two phases were separated by decantation. The gel-like precipitate was first dried in ambient air for several days until the isopropanol had completely evaporated, and then dried in a circulating air oven at 80°C for 32 hours.

[0106] The clear solvent was evaporated to dryness using a rotary evaporator, and the residue was dried overnight in a circulating air oven at 80°C.

[0107] This resulted in the recovery of 0.4197g of uncoated film containing no Pt, 0.6313g of coating containing 0.16% Pt, and 0.2405g of dissolved polymer, which corresponds to a total Pt recovery rate of 99.4%, and this is in good agreement with the value obtained from the leached film sample mentioned above.

[0108] The recovered dried film fragments contained 66% by weight of F and 3.0% by weight of S.

[0109] Comparative Example 1: Recycling process not according to the present invention - Platinum group metal leaching after delamination 1. Cutting and sorting Four catalyst coatings were prepared, attached to the subgasket. Generally, the catalyst coatings are attached to the subgasket with welded rims, as can be seen in Figure 1. These assemblies were subjected to a manual cutting process to remove the subgaskets from the catalyst coatings. The area of ​​the resulting catalyst coatings was approximately 250 cm². 2 The total mass of these membranes was 4.4900 g.

[0110] 2. Delamination The obtained films (4.4900 g) were treated with 300 g of a mixture of isopropanol and water (30 wt% isopropanol + 70 wt% water) in a shaking bath at room temperature (approximately 20°C) for 20 minutes. Each film was removed from the suspension, and any adhering coating residue was removed from the film by gently scraping with a spatula. Finally, each film was rinsed first with the isopropanol / water mixture, and then with pure water. The rinsed films were suspended with clamps and dried in ambient air to obtain a total dry mass of 1.0808 g of exfoliated film.

[0111] The resulting solvent, containing the separated coating, was centrifuged at 5000 rpm for 30 minutes (using a Universal 320 R centrifuge from Andreas Hettich GmbH & Co.KG) to obtain two phases: a clear solvent phase and a gel-like precipitate. Both phases were separated by decantation. The gel-like precipitate was transferred to a round-bottom flask, and the solvent was completely evaporated in a rotary evaporator at 70°C under vacuum to obtain 2.3264 g of dry residue. The difference of 1.0828 g between the feed mass and the mass of the coating and film corresponds to the polymer fraction dissolved in the solvent. The recovered dry film contained 66.5% by weight of F and 2.4% by weight of S.

[0112] 3.Platinum group metal leaching Next, 2.3264 g of the dried coating was treated with 149 g of an acidic aqueous solution containing hydrochloric acid (HCl: 33% by weight based on the weight of the solution + water: 67% by weight based on the weight of the solution) and 1.65 g of sodium chlorate (approximately 6:1 molar ratio NaClO3:Pt equivalent) at 80°C for 6.5 hours. The reaction mixture was filtered, and the solid residue was rinsed with 10% hydrochloric acid, and then with water until the washing water was neutral. The solid residue was dried overnight in a circulating air oven at 80°C. The dried residue had a mass of 1.8700 g and a residual Pt content of 0.63%.

[0113] The overall Pt leaching efficiency was calculated according to the formula disclosed in Analysis 4. This corresponded to a total leaching efficiency of 97.6%. [Brief explanation of the drawing]

[0114] [Figure 1] This shows the catalyst coating attached to the sub-gasket using a recycled welded rim. [Figure 2] A schematic membrane electrode assembly is shown, including a catalyst coating (CCM) having a sub-gasket (not shown) covered by a gas diffusion layer, the gas diffusion layer (4) being covered by a flow field plate (3), a metal sheet (2), and a metal grid (1). The gas diffusion layer, as well as the flow field plate, metal sheet, and metal grid, are easily removable. [Figure 3]This is a schematic diagram of the process according to an embodiment of the present invention. One or more catalyst coating films P(CCM) as small pieces are introduced into a reactor unit RU together with a first mixture M(L) containing water and a leaching agent. M(L) and P(CCM) are brought into contact in the RU and subjected to leaching conditions to obtain a mixture M1 containing metal dissolved in the first mixture and one or more catalyst coating film pieces from which the metal has been depleted. M1 is introduced into a separation unit SU, preferably a solid-liquid separation unit, to obtain one or more catalyst coating film pieces from which the metal has been depleted as a flow F(p) and metal dissolved in the first mixture as a flow F(mt). Furthermore, F(p) is introduced into a container CR together with a second mixture M(D) containing one or more C1-C8 alkyl alcohols, C1-C8 alkyl ketones, and C1-C8 alkyl esters, and subjected to delamination conditions to obtain a mixture M2 containing at least a portion of the catalyst coating present in the second mixture and one or more film pieces from which at least a portion of the catalyst coating has been depleted. M2 is removed from CR. M2 is passed through a solid-liquid separation unit SLU to obtain F(mb), i.e., one or more film fragments from which at least a portion of the catalyst coating has been depleted are separated, and F(pol), i.e., at least a portion of the catalyst coating present in the second mixture is separated, such that A2M ≤ A1M, where A2M is the amount of metal in the one or more film fragments from which the catalyst coating has been depleted obtained in CR, and A1M is the amount of metal in the one or more metal-depleted catalyst coating film fragments obtained in RU. This process may further include using one or more of F(mt), F(pol), and F(mb) to produce one or more catalyst coating films, thereby closing the loop.

[0115] References - International Publication No. 2006 / 073840(A1) - International Publication No. 2010 / 132156(A1) - International Publication No. 2015 / 010793(A2) - International Publication No. 2016 / 156815(A1) - European Patent No. 3000902(B1) - European Patent No. 3957759(A1) - European Patent No. 2036153(B1) - International Publication No. 2010 / 132156(A2)

Claims

1. A recycling process for recovering a metal from a catalyst coating film comprising a fluorocarbon-containing ionomer film and a catalyst coating containing a polymer and a metal, wherein the metal is selected from the group consisting of platinum group metals, gold, silver, copper, nickel, cobalt, rare earth metals, gallium, indium, germanium, two or more alloys thereof, and two or more mixtures thereof, and the process is, (i) To provide the catalyst coating film as one or more small pieces, (ii) The one or more catalyst-coated film pieces provided in accordance with (i) are brought into contact with a first mixture containing water and a leaching agent, subjected to leaching conditions, and a mixture M1 is obtained, which contains the metal dissolved in the first mixture and one or more catalyst-coated film pieces from which the metal has been depleted. (iii) Separating the one or more catalyst coating film fragments obtained according to (iii) from the metal dissolved in the first mixture obtained according to (ii), (iv)(iii) The one or more catalyst coating film small pieces from which the metal has been depleted, obtained according to (iv)(iii), C １ ~C ８ Alkyl alcohol, C １ ~C ８ Alkyl ketones, and C １ ~C ８ The process involves contacting a second mixture containing one or more alkyl esters with a mixture of catalysts, subjecting it to delamination conditions, and obtaining a mixture M2 containing at least a portion of the catalyst coating present in the second mixture and one or more small film fragments from which the at least portion of the catalyst coating has been depleted. Separating at least a part of the one or more membrane pieces in which at least a part of the catalyst coating obtained according to (v)(iv) has been depleted from at least a part of the catalyst coating present in the second mixture obtained according to (iv), which is A2 Ｍ ≤ A1 Ｍ where A2 Ｍ is the amount of the metal in the one or more membrane pieces in which the catalyst coating obtained according to (iv) has been depleted, and A1 Ｍ is the amount of the metal in the one or more catalyst-coated membrane pieces in which the metal obtained according to (ii) has been depleted, the separating, and a process.

2. The process according to claim 1, wherein the polymer contained in the catalyst coating is an ionomer, preferably a fluorocarbon-containing ionomer, and more preferably a perfluorosulfonic acid ionomer.

3. The process according to claim 1 or 2, wherein the metal contained in the catalyst coating is selected from the group consisting of platinum group metals, their alloys, and mixtures thereof, more preferably a platinum group metal, more preferably platinum, iridium, their alloys, and mixtures thereof, and more preferably platinum or iridium.

4. (i) is, (i.1) To provide a catalyst coating assembly including a catalyst coating film and a sub-gasket, (i.2) Cutting the catalyst coating assembly into small pieces, The process according to any one of claims 1 to 3, comprising: (i.3) sorting the small pieces obtained in accordance with (i.2) into at least two different flows to obtain a first flow containing one or more small pieces of the catalyst coating film, wherein the one or more small pieces have depleted subgaskets; and a second flow containing the subgaskets.

5. The leaching agent contained in the first mixture used in accordance with (ii) is selected from the group consisting of a Bronsted acid, a Bronsted base, or a complexing agent. The acid is preferably hydrochloric acid, sulfuric acid, nitric acid, or an organic acid. The base is preferably an alkali metal hydroxide, an alkaline earth metal hydroxide, an alkali metal carbonate, an alkaline earth metal carbonate, or an alkaline earth metal oxide. The complexing agent is preferably a compound containing one or more of ammonia, an amino group, and a thio group, a crown ether, an amino derivative crown ether, a thio derivative crown ether, a cyclophane, an amino derivative cyclophane, and a thio derivative cyclophane. Preferably, the process according to any one of claims 1 to 4, wherein the leaching agent contained in the first mixture used according to (ii) is a Bronsted acid or a Bronsted base, more preferably a Bronsted acid.

6. The process according to any one of claims 1 to 5, wherein the first mixture used in accordance with (ii) further comprises an oxidizing agent, the oxidizing agent preferably one or more of chlorates, perchlorates, hypochlorites, chlorine, bromine, ozone, oxygen, hydrogen peroxide, peroxosulfates, chromates, permanganates, ironates and Fenton's reagent, preferably one or more of chlorates, chlorine, ozone, oxygen and hydrogen peroxide, and more preferably chlorine or a chlorate.

7. The process according to any one of claims 1 to 6, wherein the first mixture used in accordance with (ii) comprises, based on the weight of the first mixture, at least 10% by weight, preferably 10 to 80% by weight, more preferably 20 to 50% by weight, and more preferably 26 to 36% by weight of the leaching agent.

8. (i) The one or more catalyst-coated film pieces provided in accordance with (i) are brought into contact with the first mixture containing water and a leaching agent, and subjected to leaching conditions in accordance with (ii), (i) includes introducing one or more catalyst-coated film pieces provided in accordance with (i) into a reactor unit containing the first mixture, mixing them, and heating the resulting mixture to a temperature in the range of 15 to 200°C, preferably 20 to 150°C, more preferably 60 to 100°C. Preferably, the process according to any one of claims 1 to 7, wherein heating according to (ii) is carried out under reflux.

9. Separation according to (iii) includes passing the M1 obtained according to (ii) through a solid-liquid separation unit, wherein the solid-liquid separation unit is preferably a sieve or filter, more preferably a sieve. Preferably, the process according to any one of claims 1 to 8 further comprises separating according to (iii) by rinsing the one or more catalyst coating film fragments on the solid-liquid separation unit with the leaching agent and / or water, more preferably deionized water.

10. The one or more catalyst coating film fragments obtained according to (iii) in which the metal has been depleted, C １ ~C ８ Alkyl alcohol, C １ ~C ８ Alkyl ketones, and C １ ~C ８ Contacting with a second mixture containing one or more alkyl esters and subjecting to delamination conditions according to (iv) is The process according to any one of claims 1 to 9, comprising introducing one or more metal-depleted catalyst coating film fragments obtained according to (iii) into a container containing the second mixture, mixing, preferably shaking, and optionally applying a shear force to the one or more film fragments by stirring, preferably using a fluid jet, scraping, or brushing.

11. C to water in the second mixture used in (iv) １ ~C ８ Alkyl alcohol, C １ ~C ８ Alkyl ketones and C １ ~C ８ The process according to any one of claims 1 to 10, wherein the weight ratio of one or more alkyl esters is in the range of 0.1:1 to 1:0, preferably in the range of 0.1:1 to 1:0.1, and more preferably in the range of 0.2:1 to 1:0.

2.

12. (vi) The further step includes drying one or more film fragments from which at least a portion of the catalyst coating obtained according to (v) has been depleted. The process described above is preferably, The process according to any one of claims 1 to 11, comprising: introducing one or more dried film fragments obtained according to (vi) into a container having an aqueous mixture having a pH in the range of 0 to 6.5, preferably 1 to 3, to obtain a mixture; and heating the mixture to a temperature in the range of 20 to 100°C.

13. (vii)(v) Further includes recovering the polymer contained in at least a portion of the catalyst coating obtained according to (v), Preferably, the polymer is recovered according to (vii). The process according to any one of claims 1 to 12, comprising passing at least a portion of the catalyst coating present in the second mixture obtained according to (v) through a separation unit to obtain the polymer, more preferably the polymer being an ionomer, more preferably a fluorine-containing ionomer.

14. A unit for carrying out the process described in any one of claims 1 to 13, A reactor unit for subjecting one or more catalyst-coated film fragments together with the first mixture to leaching conditions, Means for introducing the catalyst coating film as one or more small pieces, Means for introducing the first mixture, Means for removing M1 from the reactor unit, Separation unit and Means for introducing M1 into the separation unit, A container for subjecting one or more catalyst coating film small pieces, from which the aforementioned metal has been depleted, to delamination conditions, A means for introducing one or more catalyst coating film fragments, from which the metal has been depleted, into the container, Means for introducing the second mixture into the container, Means for removing M2 from the container, A unit comprising means for separating at least a portion of the catalyst coating present in the second mixture from one or more film fragments from which at least a portion of the catalyst coating has been depleted.

15. A process for fabricating catalyst coating films for fuel cells, (a) Perform the process described in any one of claims 1 to 13, Metals, preferably platinum group metals, more preferably platinum or iridium, Polymers, preferably ionomers, and Obtaining one or more membrane fragments, (b) A process to obtain a catalyst coating film for a fuel cell, comprising using the metal obtained according to (a), the polymer and one or more film fragments.

Images