CA1218959A - Ion-exchange membrane electrolytic apparatus and process for producing the same - Google Patents
Ion-exchange membrane electrolytic apparatus and process for producing the sameInfo
- Publication number
- CA1218959A CA1218959A CA000406878A CA406878A CA1218959A CA 1218959 A CA1218959 A CA 1218959A CA 000406878 A CA000406878 A CA 000406878A CA 406878 A CA406878 A CA 406878A CA 1218959 A CA1218959 A CA 1218959A
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- Prior art keywords
- ion
- exchange membrane
- cathode
- exchange
- electrolytic apparatus
- Prior art date
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- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B9/00—Cells or assemblies of cells; Constructional parts of cells; Assemblies of constructional parts, e.g. electrode-diaphragm assemblies; Process-related cell features
- C25B9/17—Cells comprising dimensionally-stable non-movable electrodes; Assemblies of constructional parts thereof
- C25B9/19—Cells comprising dimensionally-stable non-movable electrodes; Assemblies of constructional parts thereof with diaphragms
- C25B9/23—Cells comprising dimensionally-stable non-movable electrodes; Assemblies of constructional parts thereof with diaphragms comprising ion-exchange membranes in or on which electrode material is embedded
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B1/00—Electrolytic production of inorganic compounds or non-metals
- C25B1/01—Products
- C25B1/34—Simultaneous production of alkali metal hydroxides and chlorine, oxyacids or salts of chlorine, e.g. by chlor-alkali electrolysis
- C25B1/46—Simultaneous production of alkali metal hydroxides and chlorine, oxyacids or salts of chlorine, e.g. by chlor-alkali electrolysis in diaphragm cells
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Electrolytic Production Of Non-Metals, Compounds, Apparatuses Therefor (AREA)
- Electrodes For Compound Or Non-Metal Manufacture (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
An electrolytic apparatus comprising a cathode and an anode with an ion-exchange membrane positioned therebetween and further wherein at least one of the cathode and anode comprises a gas-liquid permeable porous plate electrode adhered closely to the ion-exchange membrane using a powdery ion-exchange resin and a process of adhering the porous electrode to the membrane by means of a powdery ion-exchange resin under heat and pressure.
An electrolytic apparatus comprising a cathode and an anode with an ion-exchange membrane positioned therebetween and further wherein at least one of the cathode and anode comprises a gas-liquid permeable porous plate electrode adhered closely to the ion-exchange membrane using a powdery ion-exchange resin and a process of adhering the porous electrode to the membrane by means of a powdery ion-exchange resin under heat and pressure.
Description
FIEI,D OF T~IE INVENTION
The present in~en-tion relates to an electrolytic ap-paratus using an ion-~xchange membrane and a process Eor producing the same~
In greater ~etail, the presen-t invention relates to an electrolytic apparatus having an ion~exchange membrane as a solid polymer electrolyte diaghragm, wherein at least one oE -the cathode and the anode composed of a gas~ uid permeable porous plate is adhered closely to the ion-exchange membrane by means of a powdery ion-exchange resin, and a process for producing the same.
BACKGROUND OF THE INVENTION
-Recently achie~ing energy economy or resource economy, such as reduction of electric power consumption or minimization of apparatus size, etc., due to rapid increases in energy cos-t, has become an important problem.
In electrolysis of aqueous solutions of sodium chloride, etc., a cathode and an anode, in the past, have been separated by a space from a diaphragm tllerebetween. As an improvement, it has been proposed to adhere closely the cathode and anode to the cation-exchange membrane, by which electric resistance due to gas generation is reduced to decrease the electrolytic voltage.
Further, various kinds of the so-called solid polymer electrolyte (SPE~ electrolytic processes are known hitherto. For example, Japanese Patent Publication 45557/76 (corresponding to U~S. Patent 3,489,670~ and Japanese Patent Application ~OPI~
787~8/77 (corresponding to U.S. Patent 4,039,409) on electrolysis of water, electrolysis of Glauber's salt, hydrolysis of hydro-chloric acid, and hydrolysis of sodium chloride, etc., are known~
In the electrolytic apparatus for the SPE process, an ion-exchange membrane is used as the electrolyte diaphragm, 1 and stratified cathode an~ anode catalyst materials are held on -the both sides of the diaphragm by being directly bonded thereto, by whi.ch electrolysis is carried ou-t. In such cases an electric current is supplied by contacting a feeder with the electrode catalyst layer~ Accordingly, they have characteristics that the distance between electrodes is reduced to the thickness of the diaphragm and theoretically the electrolytic solution is not present between the electrodes. Accordingly, it is possible to reduce the size of the apparatus to a great extent. Further, 1~0 since loss of electric resistance due to the electrolytic solution between the electrodes and generation of bubbles can be dis~
regarded, at least the corresponding value of the electrolytic voltage can be reduced. Accordingly, the SPE process is an excel-lent electrolytic system for energy economy.
However, in the prior electrode close adhesion processes and SPE processes, since bending or creases gradually occur with the ion-exchange membrane used when electrolysis is continued, a yas such as hydrogen or chlorine, etc~, caused by separation or unevenness of the ion-exchange membrane, accumulates resulting .in an inferior contact of the feeder with the electrode catalys-t layer or irregular distribution of electric current Oll the elec-trolytic surface results. Consequently, a problem arises because the electrolytic voltage rapidly increases.
A technique for solving such a problem involves in-sertion of metal wires or a mesh or a porous plate as a reinforc ing member into the inner part of the ion-exchange membrane, and a polytetrafluoroethylene dispersion is used as an adhesive.
However, insertion of a rein:Eorcing member into the thin ion exchanye membrane gives rise to problems in the production and properties thereof. Further, since adhesion of the electrode to ~L2~ 35~
1 the ion-e~chan~e membrane is still insu~ficien-t, there is the possibility of the separation of the two of them during electro-lysis for a long time, and this resistance due to the adhesive ncreases .
S~Jl'lMARY OF THE_INVENTION
The present invention provides the ability to overcome the above described problems.
An object of the present invention is to provide an electrolytic apparatus using an ion-exchange membrane, wherein the adhesion between the ion-exchange membrane and the cathode is ex-cellent and operation can be carried out in a stable manner for a long time without deformation of the ion-exchange membrane occur-ring, and a process for prod~cing the same.
In one embodiment, this invention provides an electro-lytic apparatus comprising a cathode and an anode on both sides of an ion-exchange membrane with at least one of the cathode and the anode being composed of a gas-liquid permeable porous plate elec-trode with the porous plate electrode adhering closely to the ion-exchange membrane using a powdery ion-exchange resin as a bonding agent and, in a second embodiment, a process for pro-ducing the electrolyic apparatus.
Since the present invention has such a construction, the above-described object of the present invention is attained and excellent effects are exhibited as described in detail in the following.
Namely, the present invention is based on the discovery that, in producing an electrolytic apparatus by at-kaching a porous plate electrode to an ion-exchange membrane the ion--exchange membrane is firmly bonded to theelectrode, if a powdery ion-exchange resin is used as a bonding agent for the ion-exchange membrane and the electrode.
~2~
1 Thus, according to the present invention, the ion-exchange membrane easily adheres closely and firmly to the porous plate electrode with dimensional stability arising. As the result, separation of the ion-exchange membrane does not occur even if electrolysis is carried out for a long -time~ Further t remar~able effects occur in that occurrence of bending or creases can be prevented without using the above-described reinforcing member and it becomes possible to operate in a stable manner at a low electric voltage for a long time.
DETAILED DESCRIPTION OF THE INVENTION
The ion-exchange resin used as the bonding agent is similar to the resin used for ion-exchange membrane and is one, which does not deteriorate properties of the ion-exchange membrane as an electrolyte. Further, it has an advantage of increasing the electric resistance to a lesser extent.
The ion exchange membrane used in the present invention is not restricted, and it is possible to use various kinds of ion-exchange membranes alone or as a combination thereof depending on the kind of electrolytic reaction.
Fluorine containing cation-exchange membranes having ion-exchan~e groups such as carboxylic acid ~roups, sulfonic acid ~roups, p~osphonic acid groups or phenolic hydro~yl groups, etc., are preferred for carr~ing out electrolysis of saline solutions, and other suitable ion-exchange membranes which can be used are described in U.S. Patents 3,134,697, 3,297,482, 3,341,366, 3,432,353, 3,442,825, 3,489,670 and 4,039,409.
The electrode used in the present invention should be composed of a gas-liquid permeable porous plate so that it can adhere closely to the ion-exchange membrane. It is preferred for both the cathode and the anode to adhere closely to the ion-~2~ g 1 exchange membrane~ but even one only of the cathode and the anodemaYbe adhered closely thereto. The porous plate electrode may have various shapes. For example, nets, woven materials, lattices, perforated plates, sintered porous materials, spray coa-ted porous materials and porous materials obtained by leaching out metal portions thereof, etc., can be used as they are or as electrode substrates, which are coated with an electrode active substance.
Further, it is preferred for the porous plate electrode to have a porosity of about 10 to 99% and an opening size of about 1~ to 5 mm, preferably 100~ to 1 mm, so as to facilitate passage of the electrolytic solution and removal of gases generated but so as not to cause deformation of the ion-exchange membrane by projection into the openings.
Suitable porous plate elec~rodes can be produced using various known materials by various known processes depending on the the electrolytic reaction for which the electrodes are to to used.
For example, in electrolysis of a saline solution, it is possible to use, as the cathodes, porous plates composed of iron, nickel, titanium, æirconium, niobium or alloys comprising them as a main component, such as Ti-Ta, Ti Ta-Nb etc., alloys, platinum metals such as Pt, Ru, Ir, Rh or Pd, or oxides thereof sueh as Ru02, IrO2, etc.; other metals or metal compounds such as W03, MoO2, etc.; and earbon or combinations thereof; or porous plates composed of iron, nickel or titanium, etc., which are covered with a eathode active material using known means such as a thermal decomposition process, a powder sintering process, a plating process or a spray coating process, etc. For example, flame plasma spraying.
Further, it is possible to use, as the anodes, porous plates composed of platium metals such as platinum, ruthenium, 1 palladium, iridium, rhodium, etc., or oxides thereof such as Ru02, PdO, IrO2, Rh2O3, etc.; other metals such as titanium, tantalum, tin or cobalt, etc., or oxides thereof such as TiO2, Ta2O5, SnO2~
etc.; or combinations thereof, such as RuO2-TiO2, RuO2-IrO2-Ta2O5, RuO2-SnO2-TiO2, Pt--SnO2, etc.; or porous plates composed of titanium tantalum, zirconium or electrically conductive oxides thereof such as TiO where 0<x<0.5, which are covered with an
The present in~en-tion relates to an electrolytic ap-paratus using an ion-~xchange membrane and a process Eor producing the same~
In greater ~etail, the presen-t invention relates to an electrolytic apparatus having an ion~exchange membrane as a solid polymer electrolyte diaghragm, wherein at least one oE -the cathode and the anode composed of a gas~ uid permeable porous plate is adhered closely to the ion-exchange membrane by means of a powdery ion-exchange resin, and a process for producing the same.
BACKGROUND OF THE INVENTION
-Recently achie~ing energy economy or resource economy, such as reduction of electric power consumption or minimization of apparatus size, etc., due to rapid increases in energy cos-t, has become an important problem.
In electrolysis of aqueous solutions of sodium chloride, etc., a cathode and an anode, in the past, have been separated by a space from a diaphragm tllerebetween. As an improvement, it has been proposed to adhere closely the cathode and anode to the cation-exchange membrane, by which electric resistance due to gas generation is reduced to decrease the electrolytic voltage.
Further, various kinds of the so-called solid polymer electrolyte (SPE~ electrolytic processes are known hitherto. For example, Japanese Patent Publication 45557/76 (corresponding to U~S. Patent 3,489,670~ and Japanese Patent Application ~OPI~
787~8/77 (corresponding to U.S. Patent 4,039,409) on electrolysis of water, electrolysis of Glauber's salt, hydrolysis of hydro-chloric acid, and hydrolysis of sodium chloride, etc., are known~
In the electrolytic apparatus for the SPE process, an ion-exchange membrane is used as the electrolyte diaphragm, 1 and stratified cathode an~ anode catalyst materials are held on -the both sides of the diaphragm by being directly bonded thereto, by whi.ch electrolysis is carried ou-t. In such cases an electric current is supplied by contacting a feeder with the electrode catalyst layer~ Accordingly, they have characteristics that the distance between electrodes is reduced to the thickness of the diaphragm and theoretically the electrolytic solution is not present between the electrodes. Accordingly, it is possible to reduce the size of the apparatus to a great extent. Further, 1~0 since loss of electric resistance due to the electrolytic solution between the electrodes and generation of bubbles can be dis~
regarded, at least the corresponding value of the electrolytic voltage can be reduced. Accordingly, the SPE process is an excel-lent electrolytic system for energy economy.
However, in the prior electrode close adhesion processes and SPE processes, since bending or creases gradually occur with the ion-exchange membrane used when electrolysis is continued, a yas such as hydrogen or chlorine, etc~, caused by separation or unevenness of the ion-exchange membrane, accumulates resulting .in an inferior contact of the feeder with the electrode catalys-t layer or irregular distribution of electric current Oll the elec-trolytic surface results. Consequently, a problem arises because the electrolytic voltage rapidly increases.
A technique for solving such a problem involves in-sertion of metal wires or a mesh or a porous plate as a reinforc ing member into the inner part of the ion-exchange membrane, and a polytetrafluoroethylene dispersion is used as an adhesive.
However, insertion of a rein:Eorcing member into the thin ion exchanye membrane gives rise to problems in the production and properties thereof. Further, since adhesion of the electrode to ~L2~ 35~
1 the ion-e~chan~e membrane is still insu~ficien-t, there is the possibility of the separation of the two of them during electro-lysis for a long time, and this resistance due to the adhesive ncreases .
S~Jl'lMARY OF THE_INVENTION
The present invention provides the ability to overcome the above described problems.
An object of the present invention is to provide an electrolytic apparatus using an ion-exchange membrane, wherein the adhesion between the ion-exchange membrane and the cathode is ex-cellent and operation can be carried out in a stable manner for a long time without deformation of the ion-exchange membrane occur-ring, and a process for prod~cing the same.
In one embodiment, this invention provides an electro-lytic apparatus comprising a cathode and an anode on both sides of an ion-exchange membrane with at least one of the cathode and the anode being composed of a gas-liquid permeable porous plate elec-trode with the porous plate electrode adhering closely to the ion-exchange membrane using a powdery ion-exchange resin as a bonding agent and, in a second embodiment, a process for pro-ducing the electrolyic apparatus.
Since the present invention has such a construction, the above-described object of the present invention is attained and excellent effects are exhibited as described in detail in the following.
Namely, the present invention is based on the discovery that, in producing an electrolytic apparatus by at-kaching a porous plate electrode to an ion-exchange membrane the ion--exchange membrane is firmly bonded to theelectrode, if a powdery ion-exchange resin is used as a bonding agent for the ion-exchange membrane and the electrode.
~2~
1 Thus, according to the present invention, the ion-exchange membrane easily adheres closely and firmly to the porous plate electrode with dimensional stability arising. As the result, separation of the ion-exchange membrane does not occur even if electrolysis is carried out for a long -time~ Further t remar~able effects occur in that occurrence of bending or creases can be prevented without using the above-described reinforcing member and it becomes possible to operate in a stable manner at a low electric voltage for a long time.
DETAILED DESCRIPTION OF THE INVENTION
The ion-exchange resin used as the bonding agent is similar to the resin used for ion-exchange membrane and is one, which does not deteriorate properties of the ion-exchange membrane as an electrolyte. Further, it has an advantage of increasing the electric resistance to a lesser extent.
The ion exchange membrane used in the present invention is not restricted, and it is possible to use various kinds of ion-exchange membranes alone or as a combination thereof depending on the kind of electrolytic reaction.
Fluorine containing cation-exchange membranes having ion-exchan~e groups such as carboxylic acid ~roups, sulfonic acid ~roups, p~osphonic acid groups or phenolic hydro~yl groups, etc., are preferred for carr~ing out electrolysis of saline solutions, and other suitable ion-exchange membranes which can be used are described in U.S. Patents 3,134,697, 3,297,482, 3,341,366, 3,432,353, 3,442,825, 3,489,670 and 4,039,409.
The electrode used in the present invention should be composed of a gas-liquid permeable porous plate so that it can adhere closely to the ion-exchange membrane. It is preferred for both the cathode and the anode to adhere closely to the ion-~2~ g 1 exchange membrane~ but even one only of the cathode and the anodemaYbe adhered closely thereto. The porous plate electrode may have various shapes. For example, nets, woven materials, lattices, perforated plates, sintered porous materials, spray coa-ted porous materials and porous materials obtained by leaching out metal portions thereof, etc., can be used as they are or as electrode substrates, which are coated with an electrode active substance.
Further, it is preferred for the porous plate electrode to have a porosity of about 10 to 99% and an opening size of about 1~ to 5 mm, preferably 100~ to 1 mm, so as to facilitate passage of the electrolytic solution and removal of gases generated but so as not to cause deformation of the ion-exchange membrane by projection into the openings.
Suitable porous plate elec~rodes can be produced using various known materials by various known processes depending on the the electrolytic reaction for which the electrodes are to to used.
For example, in electrolysis of a saline solution, it is possible to use, as the cathodes, porous plates composed of iron, nickel, titanium, æirconium, niobium or alloys comprising them as a main component, such as Ti-Ta, Ti Ta-Nb etc., alloys, platinum metals such as Pt, Ru, Ir, Rh or Pd, or oxides thereof sueh as Ru02, IrO2, etc.; other metals or metal compounds such as W03, MoO2, etc.; and earbon or combinations thereof; or porous plates composed of iron, nickel or titanium, etc., which are covered with a eathode active material using known means such as a thermal decomposition process, a powder sintering process, a plating process or a spray coating process, etc. For example, flame plasma spraying.
Further, it is possible to use, as the anodes, porous plates composed of platium metals such as platinum, ruthenium, 1 palladium, iridium, rhodium, etc., or oxides thereof such as Ru02, PdO, IrO2, Rh2O3, etc.; other metals such as titanium, tantalum, tin or cobalt, etc., or oxides thereof such as TiO2, Ta2O5, SnO2~
etc.; or combinations thereof, such as RuO2-TiO2, RuO2-IrO2-Ta2O5, RuO2-SnO2-TiO2, Pt--SnO2, etc.; or porous plates composed of titanium tantalum, zirconium or electrically conductive oxides thereof such as TiO where 0<x<0.5, which are covered with an
2-x anode active substance using known means such as a thermal de-composition process, a sintering process, a plating process or a spray coating process, etc, as described in U.S. Patents
3,711,385, 3,632,498, etcO
The resulting porous plate electrode is adhered closely to the above-described ion-exchange membrane using a powdery ion exchange resin.
Examples of powdery ion-exchange resins which can be used include known resins having sulfonic acid groups, sulfonamide groups or carboxylic acid groups, etc. as ion-exchange groups, and the resins used in producing the membranes in the documents referred to above can be employed in a powdery form. However, it is preferred to use the same ion-exchange resin as the ion-exchange membrane having an ion-exchange capacity of about 0Ol to 3 milliequivalents per gram of the dry resin, in order to improve the close adhesion of the ion-exchange membrane to the electrode without deteriorating the elec-trolytic ability thereof. For example, in case of using Nafion ~120 or #110 (Nafion is a trademark of E.I. du Pont de Nemours Co., Inc.~
as the ion-exchange men~rane, it is preferred to use a powder of the same resin as descxibed above or available powdery ion-exchange resin such as Nafion #501 or #511.
Although the paxticle si2e of the powdery ion-exchange resin may be suita~ly selected, it is preferred for the average particle size to be equal to or less than the average open-ing size of the porous pla-te electrode. Generally, powdery ion-exchange resins having an average particle size of about 0.5 to 1 n~ are used. When the ion-exchange resin powder with such a particle size is used as the bonding agent, it easily permeates into openings of the porous plate electrocle upon heat ~rea-~ment under pressure and becomes impregnated therein or used therein by which ~le ion-exchange memhrane is aclhered firmly and closely to the porous plate electrodeO
Various rQeans can be utilized for bonding the porous plate electrode to ~he ion-exchange membrane using the pow~ery ion-exchan~e resin. The simplest process comprises applying a powder of the ion~exchange resin to a surface of the porous plate electrode or the ion~-exchange membrane in a unifo~m thickness, and pressing both of them simultaneously alon~ ~`7i~h a h~al~lng of t~e boncling faces from, prefera~)ly, the ~lec~rocle ~:ide to fuse ~he ion~exchange resin. I~ is preerrecl :E~or ~..he hea~ing temperatiur2 to be çlbOUt 80 to 3~30C and J.he bonding pressure to be ~out 10 to 1000 l~J/cl-n~. rrhe hea~ txea~nent under pressure can be carxi.ec~ out in ~he air or, i~ ~esired, in a~ inert 39~
1 atmosphere such.as of ni.trogen or argon, etc. Further~ it is also possible to use a process w~ich comprises previously impreg-nat~ng the surface of the porous plate electrode to be ~onded wîth. the powdery ion-exchange resi:n by mechanical introduction under pressure or hy applying a liquid dispersion of a powdery ion-exchange resin and, if desired, fusing by heating to form a bonding agent layer on the surface of the porous plate electrode f and bonding the ion~exchange membrane thereto under pressure with heat. Further, it is possible to use a process which comprises attaching a powdery ion exchan~e resin as a bonding agent to a side or both sides of the ion exchange membrane during production thereof, and bonding the porous plate electrode to the ion~
exchange membrane under pressure with heat, This latter process provides the advantages that the adhesion of t.he ;on~exchange resin to the ion-exchange membrane and the adhesion of the ion-exchange resin to .he porous plate elec~rode can be carried out under optimum conditions, respectivel,v.
~ here a porous plate electrode which is covered with an electrode active substance is used as an electrically conductive porous electrode substrate, it is possible to use a process which comprises bonding closely the ion;exchange membrane to the elec-txically conductive porous electrode substrate using the powdery ion-exchange resin employing the above-described process, and therea~ter coating the electrode substrate with t~e electrode active substance. In this process, coating with the electrode catalyst substance must b~ conducted under conditions where the ion-exchange membrane is not broken, such as by using a sputtering process, a plating process or an evaporation process, etc~
3~
35~
1 Further, the process accordiny -to the present invention can be employed not only in the c~se of providing a porous in~c~ive layer between the ion-exchange membrane and the electrode but also in production of other analogous electrolytic cells.
The present inven-tion i5 illustrated below by reference to the following examples, but the present inven-tion is not to be construed to be limited by these examples.
To a 20 mesh ~mesh spacing: about 0.7 mm) nickel net having a wire diameter of 0.5 mm and an area of abou-t 50 cm , a nickel powder having an average particle size of 100~ was applied by sintering for 10 minutes at 900C in a H2 atmosphere to produce a porous plate cathode wherein a porous layer having a thickness of about 200~ and a porosity of about 80% was formed on a face to which an ion-exchange membrane was adhered.
On the other hand, a commercially available ion-exchange resin (ion-exchange capaci-ty: about 0,8 milliequivalent/l g of dry resin) ~Nafion ~501) was powdered to an average particle si~e of 70~. The above-described cathode porous layer was sufficiently impregnated with the resulting powder, and further a small amount, e.g., about 5 g/m2, of the same powder was applied thereto. A
cation-exchange membrane of Nafion #120 was put on the processed layer, and adhesion of the ion-exchange membrane and the nickel porous cathode was carried out by pressing at a temperature of 250C under a pressure of 10 kg/cm2.
_g IJsing all expansion mesh having a thickness of 2 mm as an anode, an electrolytic cell ~7as constructed by placing the anode at a distance of 3 mm from the ion~exchange membrane.
For the purpose of comparison, an electrolytic cell was used wherein the above-described cathode wi~hout the ion-exchanc3e ~embrane bonded thereto w~s placed at a distance of 1. 5 mm.
As a result o~ electrolysis at 40C by supplyin~ a 10% a~ue-ous solution of NaOH -to the cathode chamber and the anode cha~ er, respectively, ~he electrol~tic voltage ~7ith the cathode bonded to the ion-exchange membrane accordillg to the present invention was abou-t 200 mV lower than that with the cathode not bonded ~o the ion exchange membrane. Further, separation of the ion-exchanye me~brane from the cathode was not observed after ~lectrolysis had been carr:ied out ~or 15 about 1000 hours, and thus operation ~ould be continued in a stable ma~ner~
EX~LE 2 To a rolled ~itanium mesh having a thic}3ness o 0.1 mm and an opening ratio o~ 60%, a titanium powd~r haviny an 20 . average particle size of about 50,u was applied to form a porous- layer, and the layer was sintexed at 1100C for 20 minutes in a vacuum ~10 5 Torr) to produce a por~us plate having a thic]~ess of about ~0~ and a porosity of about 80%.
This porous plate was covered with a compound oxide o~ Ru ~5 aIlcl ~l'i in a metal raJcio o~ 60:~0 ~y ~eiyh-t us:i.ng a c:on ventional ~he.rmal d~comlposition p.rocess to pxoduce a pc~rous plate ano~
~ l~xl::, th~ S~ Ce 0:E ~ht~ a~ove described porolls ano;~e W~IS i-lnpr~nated Wi~l ~?owclered Nafion i~500 (ion exchange 3~ capacit~y of a'oollt 0.~ rnilliequival~nts~l g of dry leS.i;l) .'~'2,~
having an average particle size of 20~ or less, and a Nafion #315 ion-exchange membrane was bonded to the above-described sur~ace at 250C by pressing at a pressure of 20 kg/cm~.
Platinum black (specific surface area 30 m2/g) and a polytetrafluoroethylene dispersion were blended in a ratio by weight of 100:30. The mixture was applied to the other sur~ace of the a~o~e-described ion-exchange membrane to form a cathode layer, and an electrolytic cell was constructed using it.
For the purpose of comparison, an electrolytic cell which was constructed in the same manner, except that the anode was bonded direc-tly to the ion exchange membrane without using the ion-exchange resin powder was used.
As a result of electrolysis at 80C by supplying a
The resulting porous plate electrode is adhered closely to the above-described ion-exchange membrane using a powdery ion exchange resin.
Examples of powdery ion-exchange resins which can be used include known resins having sulfonic acid groups, sulfonamide groups or carboxylic acid groups, etc. as ion-exchange groups, and the resins used in producing the membranes in the documents referred to above can be employed in a powdery form. However, it is preferred to use the same ion-exchange resin as the ion-exchange membrane having an ion-exchange capacity of about 0Ol to 3 milliequivalents per gram of the dry resin, in order to improve the close adhesion of the ion-exchange membrane to the electrode without deteriorating the elec-trolytic ability thereof. For example, in case of using Nafion ~120 or #110 (Nafion is a trademark of E.I. du Pont de Nemours Co., Inc.~
as the ion-exchange men~rane, it is preferred to use a powder of the same resin as descxibed above or available powdery ion-exchange resin such as Nafion #501 or #511.
Although the paxticle si2e of the powdery ion-exchange resin may be suita~ly selected, it is preferred for the average particle size to be equal to or less than the average open-ing size of the porous pla-te electrode. Generally, powdery ion-exchange resins having an average particle size of about 0.5 to 1 n~ are used. When the ion-exchange resin powder with such a particle size is used as the bonding agent, it easily permeates into openings of the porous plate electrocle upon heat ~rea-~ment under pressure and becomes impregnated therein or used therein by which ~le ion-exchange memhrane is aclhered firmly and closely to the porous plate electrodeO
Various rQeans can be utilized for bonding the porous plate electrode to ~he ion-exchange membrane using the pow~ery ion-exchan~e resin. The simplest process comprises applying a powder of the ion~exchange resin to a surface of the porous plate electrode or the ion~-exchange membrane in a unifo~m thickness, and pressing both of them simultaneously alon~ ~`7i~h a h~al~lng of t~e boncling faces from, prefera~)ly, the ~lec~rocle ~:ide to fuse ~he ion~exchange resin. I~ is preerrecl :E~or ~..he hea~ing temperatiur2 to be çlbOUt 80 to 3~30C and J.he bonding pressure to be ~out 10 to 1000 l~J/cl-n~. rrhe hea~ txea~nent under pressure can be carxi.ec~ out in ~he air or, i~ ~esired, in a~ inert 39~
1 atmosphere such.as of ni.trogen or argon, etc. Further~ it is also possible to use a process w~ich comprises previously impreg-nat~ng the surface of the porous plate electrode to be ~onded wîth. the powdery ion-exchange resi:n by mechanical introduction under pressure or hy applying a liquid dispersion of a powdery ion-exchange resin and, if desired, fusing by heating to form a bonding agent layer on the surface of the porous plate electrode f and bonding the ion~exchange membrane thereto under pressure with heat. Further, it is possible to use a process which comprises attaching a powdery ion exchan~e resin as a bonding agent to a side or both sides of the ion exchange membrane during production thereof, and bonding the porous plate electrode to the ion~
exchange membrane under pressure with heat, This latter process provides the advantages that the adhesion of t.he ;on~exchange resin to the ion-exchange membrane and the adhesion of the ion-exchange resin to .he porous plate elec~rode can be carried out under optimum conditions, respectivel,v.
~ here a porous plate electrode which is covered with an electrode active substance is used as an electrically conductive porous electrode substrate, it is possible to use a process which comprises bonding closely the ion;exchange membrane to the elec-txically conductive porous electrode substrate using the powdery ion-exchange resin employing the above-described process, and therea~ter coating the electrode substrate with t~e electrode active substance. In this process, coating with the electrode catalyst substance must b~ conducted under conditions where the ion-exchange membrane is not broken, such as by using a sputtering process, a plating process or an evaporation process, etc~
3~
35~
1 Further, the process accordiny -to the present invention can be employed not only in the c~se of providing a porous in~c~ive layer between the ion-exchange membrane and the electrode but also in production of other analogous electrolytic cells.
The present inven-tion i5 illustrated below by reference to the following examples, but the present inven-tion is not to be construed to be limited by these examples.
To a 20 mesh ~mesh spacing: about 0.7 mm) nickel net having a wire diameter of 0.5 mm and an area of abou-t 50 cm , a nickel powder having an average particle size of 100~ was applied by sintering for 10 minutes at 900C in a H2 atmosphere to produce a porous plate cathode wherein a porous layer having a thickness of about 200~ and a porosity of about 80% was formed on a face to which an ion-exchange membrane was adhered.
On the other hand, a commercially available ion-exchange resin (ion-exchange capaci-ty: about 0,8 milliequivalent/l g of dry resin) ~Nafion ~501) was powdered to an average particle si~e of 70~. The above-described cathode porous layer was sufficiently impregnated with the resulting powder, and further a small amount, e.g., about 5 g/m2, of the same powder was applied thereto. A
cation-exchange membrane of Nafion #120 was put on the processed layer, and adhesion of the ion-exchange membrane and the nickel porous cathode was carried out by pressing at a temperature of 250C under a pressure of 10 kg/cm2.
_g IJsing all expansion mesh having a thickness of 2 mm as an anode, an electrolytic cell ~7as constructed by placing the anode at a distance of 3 mm from the ion~exchange membrane.
For the purpose of comparison, an electrolytic cell was used wherein the above-described cathode wi~hout the ion-exchanc3e ~embrane bonded thereto w~s placed at a distance of 1. 5 mm.
As a result o~ electrolysis at 40C by supplyin~ a 10% a~ue-ous solution of NaOH -to the cathode chamber and the anode cha~ er, respectively, ~he electrol~tic voltage ~7ith the cathode bonded to the ion-exchange membrane accordillg to the present invention was abou-t 200 mV lower than that with the cathode not bonded ~o the ion exchange membrane. Further, separation of the ion-exchanye me~brane from the cathode was not observed after ~lectrolysis had been carr:ied out ~or 15 about 1000 hours, and thus operation ~ould be continued in a stable ma~ner~
EX~LE 2 To a rolled ~itanium mesh having a thic}3ness o 0.1 mm and an opening ratio o~ 60%, a titanium powd~r haviny an 20 . average particle size of about 50,u was applied to form a porous- layer, and the layer was sintexed at 1100C for 20 minutes in a vacuum ~10 5 Torr) to produce a por~us plate having a thic]~ess of about ~0~ and a porosity of about 80%.
This porous plate was covered with a compound oxide o~ Ru ~5 aIlcl ~l'i in a metal raJcio o~ 60:~0 ~y ~eiyh-t us:i.ng a c:on ventional ~he.rmal d~comlposition p.rocess to pxoduce a pc~rous plate ano~
~ l~xl::, th~ S~ Ce 0:E ~ht~ a~ove described porolls ano;~e W~IS i-lnpr~nated Wi~l ~?owclered Nafion i~500 (ion exchange 3~ capacit~y of a'oollt 0.~ rnilliequival~nts~l g of dry leS.i;l) .'~'2,~
having an average particle size of 20~ or less, and a Nafion #315 ion-exchange membrane was bonded to the above-described sur~ace at 250C by pressing at a pressure of 20 kg/cm~.
Platinum black (specific surface area 30 m2/g) and a polytetrafluoroethylene dispersion were blended in a ratio by weight of 100:30. The mixture was applied to the other sur~ace of the a~o~e-described ion-exchange membrane to form a cathode layer, and an electrolytic cell was constructed using it.
For the purpose of comparison, an electrolytic cell which was constructed in the same manner, except that the anode was bonded direc-tly to the ion exchange membrane without using the ion-exchange resin powder was used.
As a result of electrolysis at 80C by supplying a
4 N aqueous solution of NaCl to the anode chamber and a 20% aqueous solution of NaOH to the cathode chamber, opera-tion in a stable manner can be carried out according to the present invention at an average electrolytic voltage of 3.3 V for 1000 hours or more, and separation of the anode from the ion~exchange membrane was not observed at all. In the comparison electrolysis, separation of the anode from the ion-exchange membrane occurred to result in a .rapid increase of the electrolytic voltage of 1.0 V or more after 15 m:in~ltes f.t:om the e:l.e~i;.rolysis operati.on was startecl.
~lP~ 3 r~ a -~ ss o~ a~ou-~ ~. mm m~ Mo~ .roc~ u~ o~no ~ d. L-tdo 3 ~
.rolled to prepare a ~orous plate havj.ng a thickness of 3~ 0~3 ~ lcl ~ po~ o~ g0%. It 1,~7a~ ~o~ced ~`7i ~h p ,~
in a thickness of about 1~ using a thermal decompositi.on process to produce a cathode. Then the surface thereof was impregnated with a powder of an ion-exchange resin (Nafion #501~ having an average particle size of 50~ in a thickness of about 0.2 mm. An a~uminium foil was put on the resulting porous cathode, and the assembly pressed at a temperature of 300C under a pressure of 200 kg/m2 in a nitrogen atmosphere. When the aluminum foil was removed, a uniform layer of the ion-exchange resin which adhered closely to one side of the nickel porous cathode pla~e was formed.
Then, to the resulting membrane layer, an ion~exchange membrane (Naflon ~31~) was adhered by pressing at 250C
under 150 kg/m2.
A Ti mesh coated with a compound oxide of ~uo2:Tio2 - 1:1 by weight was used as an anode, which was placed at a distance of 2 mm from the ion-exchange membrane to construct an electrolytic cell. ~hen electrolysis was carrie~ out under the same condition as in ~xample ~, operati.on in a stable manner c~n be carried out at an electrolytic voltage of about 3~3 V for 1000 hours or more, and separation of the nickel porous cathode ~rom the ion-e.xchange membrane was not observed.
While the invention has been described in detail and with re:Eerence to spec.i.~ic er~bodlmen~s ~hereof, it will be appare~lt to one sl~illed in the art ~hat various chan~es and snodi~`icaclo.lls cag~ e .made therein wi~hout departing ~xom the ~iri~ co~
:.
)~
~lP~ 3 r~ a -~ ss o~ a~ou-~ ~. mm m~ Mo~ .roc~ u~ o~no ~ d. L-tdo 3 ~
.rolled to prepare a ~orous plate havj.ng a thickness of 3~ 0~3 ~ lcl ~ po~ o~ g0%. It 1,~7a~ ~o~ced ~`7i ~h p ,~
in a thickness of about 1~ using a thermal decompositi.on process to produce a cathode. Then the surface thereof was impregnated with a powder of an ion-exchange resin (Nafion #501~ having an average particle size of 50~ in a thickness of about 0.2 mm. An a~uminium foil was put on the resulting porous cathode, and the assembly pressed at a temperature of 300C under a pressure of 200 kg/m2 in a nitrogen atmosphere. When the aluminum foil was removed, a uniform layer of the ion-exchange resin which adhered closely to one side of the nickel porous cathode pla~e was formed.
Then, to the resulting membrane layer, an ion~exchange membrane (Naflon ~31~) was adhered by pressing at 250C
under 150 kg/m2.
A Ti mesh coated with a compound oxide of ~uo2:Tio2 - 1:1 by weight was used as an anode, which was placed at a distance of 2 mm from the ion-exchange membrane to construct an electrolytic cell. ~hen electrolysis was carrie~ out under the same condition as in ~xample ~, operati.on in a stable manner c~n be carried out at an electrolytic voltage of about 3~3 V for 1000 hours or more, and separation of the nickel porous cathode ~rom the ion-e.xchange membrane was not observed.
While the invention has been described in detail and with re:Eerence to spec.i.~ic er~bodlmen~s ~hereof, it will be appare~lt to one sl~illed in the art ~hat various chan~es and snodi~`icaclo.lls cag~ e .made therein wi~hout departing ~xom the ~iri~ co~
:.
)~
Claims (11)
1. An electrolytic apparatus comprising a cathode and an anode with an ion-exchange membrane positioned therebetween and further wherein at least one of said cathode and anode comprises a gas-liquid permeable porous plate electrode adhered closely to said ion-exchange membrane using an ion-exchange resin that is in the form of powder prior to use as a bonding agent.
2. The electrolytic apparatus according to claim 1, wherein the ion-exchange membrane and the ion-exchange resin powder each have an ion-exchange capacity of about 0.1 to 3 milliequivalents per gram of dry resin.
3. The electrolytic apparatus according to claim 1, wherein the cathode comprises the gas-liquid permeable porous plate electrode adhered closely to the ion-exchange membrane using the ion-exchange resin.
4. The electrolytic apparatus according to claim 1, wherein at least the cathode comprises the porous plate electrode adhered closely to the ion-exchange membrane and is prepared by (1) sintering a nickel powder, or (2) applying a nickel powder to a nickel porous material by sintering.
5. The electrolytic apparatus according to claim 3, wherein the cathode was prepared by (1) sintering a nickel powder, or (2) applying a nickel powder to a nickel porous material by sintering.
6. The electrolytic apparatus according to claim 1 or 3, wherein the cathode comprises the porous plate electrode adhered closely to the ion-exchange membrane and is prepared by (1) plating a nickel porous material with a platinum metal, or (2) plating a nickel-powder-sintered product with a platinum metal.
7. The electrolytic apparatus according to claim 4 or 5, wherein the cathode was prepared by (1) plating a nickel porous material with a platinum metal, or (2) plating a nickel powder-sintered product with a platinum metal.
8. The electrolytic apparatus according to claim 1, wherein the anode comprises the gas-liquid permeable porous plate electrode adhered closely to the ion-exchange membrane by using the ion-exchange resin.
9. The electrolytic apparatus according to claim 1 or 8, wherein at least the anode comprises the porous plate electrode adhered closely to the ion-exchange membrane and is prepared by sintering a titanium powder or by applying a titanium powder to a titanium porous material by sintering, and wherein said porous plate further is coated with a melt oxide electrode catalyst.
10. A process for bonding an electrode and a membrane in an electrolytic apparatus having a cathode and an anode with an ion-exchange membrane positioned therebetween, which comprises:
forming a gas-liquid permeable porous plate electrode as at least one of the cathode or the anode;
adhering said porous plate electrode to the ion-exchange membrane by using a powdery ion-exchange resin under pressure with heat.
forming a gas-liquid permeable porous plate electrode as at least one of the cathode or the anode;
adhering said porous plate electrode to the ion-exchange membrane by using a powdery ion-exchange resin under pressure with heat.
11. A process according to claim 10, wherein said process comprises adhering an ion-exchange membrane to an electrically conductive porous material as an electrode substrate using said powdery ion-exchange resin by pressing with heat, and coating said electrode substrate with a gas-liquid permeable electrode active material.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56113053A JPS5816082A (en) | 1981-07-21 | 1981-07-21 | Electrolytic device using ion exchange membrane and production thereof |
| JP113053/81 | 1981-07-21 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1218959A true CA1218959A (en) | 1987-03-10 |
Family
ID=14602297
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000406878A Expired CA1218959A (en) | 1981-07-21 | 1982-07-08 | Ion-exchange membrane electrolytic apparatus and process for producing the same |
Country Status (10)
| Country | Link |
|---|---|
| JP (1) | JPS5816082A (en) |
| KR (1) | KR850001181B1 (en) |
| CA (1) | CA1218959A (en) |
| DE (1) | DE3226347C2 (en) |
| FR (1) | FR2510143B1 (en) |
| GB (1) | GB2103658B (en) |
| IT (1) | IT1189321B (en) |
| MY (1) | MY8600256A (en) |
| PH (1) | PH17767A (en) |
| SE (1) | SE453203B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59159991A (en) * | 1983-03-03 | 1984-09-10 | Japan Storage Battery Co Ltd | Method for joining ion exchange membrane to electrode as one body |
| WO2020152208A1 (en) | 2019-01-24 | 2020-07-30 | Atotech Deutschland Gmbh | Membrane anode system for electrolytic zinc-nickel alloy deposition |
| WO2023117404A2 (en) * | 2021-12-22 | 2023-06-29 | Paul Francis Geary | Flow through electrode assembly and stack |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS526374A (en) * | 1975-07-07 | 1977-01-18 | Tokuyama Soda Co Ltd | Anode structure for electrolysis |
| DE2640097A1 (en) * | 1976-09-06 | 1978-05-11 | Tokuyama Soda Kk | Diaphragm for electrolysis of alkali metal halide - comprises a body of high polymer contg. fluorine and sulphonyl and carboxyl gps. |
| JPS5620178A (en) * | 1979-07-30 | 1981-02-25 | Asahi Glass Co Ltd | Closely sticking method for ion exchange membrane and electrode |
| IT1122385B (en) * | 1979-08-01 | 1986-04-23 | Oronzio De Nora Impianti | ELECTRODE FOR SOLID ELECTROLYTE ELECTROCHEMICAL CELLS |
| NL8100168A (en) * | 1980-02-11 | 1981-09-01 | Ppg Industries Inc | SOLID POLYMERIC ELECTROLITE AND METHOD FOR MANUFACTURING THAT. |
| BR8202395A (en) * | 1981-05-01 | 1983-04-12 | Du Pont | MEMBRANE COMPOSITE SET / ELECTROCHEM CELL ELECTRODE AND ELECTROLYSIS PROCESS |
-
1981
- 1981-07-21 JP JP56113053A patent/JPS5816082A/en active Granted
-
1982
- 1982-07-08 CA CA000406878A patent/CA1218959A/en not_active Expired
- 1982-07-14 DE DE3226347A patent/DE3226347C2/en not_active Expired
- 1982-07-15 GB GB08220604A patent/GB2103658B/en not_active Expired
- 1982-07-16 PH PH27579A patent/PH17767A/en unknown
- 1982-07-19 IT IT48840/82A patent/IT1189321B/en active
- 1982-07-20 SE SE8204406A patent/SE453203B/en not_active IP Right Cessation
- 1982-07-21 FR FR828212760A patent/FR2510143B1/en not_active Expired
- 1982-07-21 KR KR8203256A patent/KR850001181B1/en active
-
1986
- 1986-12-30 MY MY256/86A patent/MY8600256A/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| DE3226347C2 (en) | 1987-04-30 |
| IT8248840A0 (en) | 1982-07-19 |
| PH17767A (en) | 1984-12-06 |
| FR2510143B1 (en) | 1989-04-21 |
| MY8600256A (en) | 1986-12-31 |
| JPS5816082A (en) | 1983-01-29 |
| SE8204406D0 (en) | 1982-07-20 |
| JPS614915B2 (en) | 1986-02-14 |
| KR840000671A (en) | 1984-02-25 |
| KR850001181B1 (en) | 1985-08-19 |
| GB2103658B (en) | 1985-01-30 |
| SE453203B (en) | 1988-01-18 |
| SE8204406L (en) | 1983-01-22 |
| GB2103658A (en) | 1983-02-23 |
| IT1189321B (en) | 1988-02-04 |
| FR2510143A1 (en) | 1983-01-28 |
| DE3226347A1 (en) | 1983-02-10 |
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