EP0126490A1 - Diaphragm based on nickel oxide and process for its manufacture - Google Patents
Diaphragm based on nickel oxide and process for its manufacture Download PDFInfo
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- EP0126490A1 EP0126490A1 EP84105869A EP84105869A EP0126490A1 EP 0126490 A1 EP0126490 A1 EP 0126490A1 EP 84105869 A EP84105869 A EP 84105869A EP 84105869 A EP84105869 A EP 84105869A EP 0126490 A1 EP0126490 A1 EP 0126490A1
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- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B13/00—Diaphragms; Spacing elements
- C25B13/04—Diaphragms; Spacing elements characterised by the material
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- the invention relates to a diaphragm based on nickel oxide for alkaline water electrolysis and to a method for producing the same.
- the alkaline water electrolysis generally takes place at relatively low temperatures (below 90 ° C.), which must be chosen in hot KOH because of the low chemical resistance of the asbestos diaphragms usually used. These low temperatures are both thermodynamically and kinetically disadvantageous an unnecessarily high electrolysis voltage is required, and the whole process appears uneconomical for energy reasons.
- Potassium silicate was added to the KOH electrolyte to reduce asbestos solubility in KOH (RLVic et al in Hydrogen Energy Progress IV, 4th WHE Conference, June 13-17, 1982, California, pp. 129-140). It is clear that this measure is not ultimately satisfactory can be viewed.
- Porous metallic diaphragms made of sintered nickel have also been proposed (P. Perroud, G. Terrier: "Hydrogen Energy System", Proc. 2nd WHE Conference, Zurich 1978, p. 241). These have a very low electrical resistance and are also mechanically stable and inexpensive.
- the major disadvantage, however, is that this diaphragm, like the electrodes, is also electron-conductive and there is too great a risk of short-circuiting in a compact design.
- porous nickel oxide diaphragms have been developed by the applicant (DE-OSes 29 27 566 and 30 31 064), which are produced by oxidation of sintered metal at elevated temperature (DE-OS 29 27 566) or more simply by oxidizing firing a carrier pressed nickel powder layer can be obtained (DE-OS 30 31 064).
- These NiO diaphragms have excellent properties as separators for alkaline water electrolysis.
- Such a reductive attack by hydrogen is not subject to ceramic diaphragms made of thermodynamically stable oxide compounds, such as Zr0 2 , BaTiO 3 , K 2 Ti 6 0 13 etc. (see above), but the manufacture of such diaphragms has the disadvantages mentioned above, in particular very high manufacturing temperatures, and they are attacked in 10 N KOH at elevated temperature with time.
- the "in situ" NiO diaphragm according to DE-OS 30 31 064 is alkali-resistant and its manufacture not only starts from a cheap starting material, but also offers the decisive technological advantage that the exothermic reaction 2 Ni + 0 2 ⁇ 2 Ni0 only expires when the diaphragm is manufactured. This results in a considerable temperature increase locally and the external manufacturing temperature can only be 1000 ° C., which is advantageous. Due to the manufacturing process (oxidizing sintering), there is also no need to maintain an inert atmosphere, which is also a significant relief.
- the invention is therefore based on the object, the reduction stability of the nickel oxide diaphragms to improve under the conditions of alkaline water electrolysis.
- the nickel oxide-based diaphragm according to the invention developed for this purpose is characterized by a content of 0.5 to 10% by weight of titanium (in oxidized form; based on the oxide mass).
- NiO 2 was added to the nickel powder in the preparation of the diaphragm in amounts of 1 to 20% by weight (based on the sum of metallic nickel and titanium dioxide) .
- the grain size of the admixed powder should be approximately comparable or smaller than that of the nickel powder in order to ensure a uniform distribution of the titanium over the oxide mass.
- titanium powder can also be admixed to the nickel powder mass in the manufacture of the diaphragm, or else as a compound, which transform into titanium oxide during the oxidizing sintering treatment. If necessary, a nickel oxide diaphragm which has already been produced can also be impregnated with a titanium compound which is converted into oxidized form by afterburning.
- the assembly was sintered in air at 1050 ° C for about 20 minutes.
- the chemical stability was, however, greatly improved, as can be seen from FIGS. 1 and 2:
- the decrease in oxygen in a pure hydrogen atmosphere at 140 to 170 ° C. can no longer be measured during the first 2000 h, which indicates an enormously increased reduction stability.
- a diaphragm made of pure NiO loses 7% of the oxygen in 2000 hours and even a diaphragm stabilized with A1 2 0 3 additive still loses about 1.5% of the oxygen content in the same time.
- the already excellent chemical stability in hot KOH is further increased: As FIG. 2 shows, the total weight loss after 2000 hours in 10 N KOH at 120 ° C. is only 0.3%.
- a pure NiO diaphragm loses 0.8%, a BaTi0 3 diaphragm 2% and a diaphragm mixed with 5% Al 2 O 3 8% of the total weight, which is attributable to A1 2 0 3 .
- Example 1 Before the slurrying step, 8% by weight of metallic Ti (based on the powder mixture) of approximately the same grain size as Ni was added to the Ni powder. The subsequent production steps were the same as in Example 1. After the oxidizing sintering, both nickel and titanium were present in oxidic form. This diaphragm had the same properties as that of Example 1 with respect to the reducibility in H 2 atmosphere.
- Example 1 50% TiO 2 was added to the Ni powder before slurrying. Otherwise, the preparation corresponded to that of Example 1.
- the diaphragm produced in this way showed a weight loss of 10% after only 500 hours in 10 N KOH at 120 ° C.
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Abstract
Description
Die Erfindung bezieht sich auf ein Diaphragma auf Nickeloxidbasis für alkalische Wasserelektrolyse sowie auf ein Verfahren zur Herstellung desselben.The invention relates to a diaphragm based on nickel oxide for alkaline water electrolysis and to a method for producing the same.
Die alkalische Wasserelektrolyse erfolgt im allgemeinen bei relativ niedrigen Temperaturen (unter 90 OC)", die wegen der geringen chemischen Beständigkeit der üblicherweise angewandten Asbest-Diaphragmen in heißer KOH gewählt werden müssen. Diese niedrigen Temperaturen sind sowohl thermodynamisch als auch kinetisch nachteilig: Dadurch ist eine unnötig hohe Elektrolysespannung erforderlich, und der ganze Prozeß erscheint aus energetischen Gründen unwirtschaftlich.The alkaline water electrolysis generally takes place at relatively low temperatures (below 90 ° C.), which must be chosen in hot KOH because of the low chemical resistance of the asbestos diaphragms usually used. These low temperatures are both thermodynamically and kinetically disadvantageous an unnecessarily high electrolysis voltage is required, and the whole process appears uneconomical for energy reasons.
Aus diesem Grunde wurden in jüngster Zeit zahlreiche Versuche unternommen, entweder die Asbestbeständigkeit in heißer KOH zu verbessern oder andere Diaphragmamaterialien zu finden.For this reason, numerous attempts have recently been made to either improve asbestos resistance in hot KOH or to find other diaphragm materials.
So wurde dem KOH-Elektrolyten Kaliumsilikat zugesetzt, um die Asbestlöslichkeit in KOH zu vermindern (R.L.Vic et al in Hydrogen Energy Progress IV, 4th WHE Conference, 13-17 Juni 1982, Kalifornien, S. 129 - 140). Es ist klar, daß diese Maßnahme nicht als endgültig befriedigend angesehen werden kann.Potassium silicate was added to the KOH electrolyte to reduce asbestos solubility in KOH (RLVic et al in Hydrogen Energy Progress IV, 4th WHE Conference, June 13-17, 1982, California, pp. 129-140). It is clear that this measure is not ultimately satisfactory can be viewed.
Von den gleichen Autoren wurde auch ein Diaphragma aus teflon-gebundenem Kaliumhexatitanat verwendet, das ursprünglich von Energy Res. Corp. entwickelt worden ist (s. auch M.S. Casper, "Hydrogen Manufacture by Electrolysis, Thermal Decomposition and Unusual Techniques", Noyes Data Corp., Park Ridge, 1978, S. 190). Dieses Diaphragma ist jedoch nicht sonderlich preiswert, und der vom Diaphragma herrührende Spannungsabfall ist mit dem von Asbestdiaphragmen vergleichbar (vgl. M.S. Casper).The same authors also used a teflon-bound potassium hexatitanate diaphragm originally from Energy Res. Corp. has been developed (see also M.S. Casper, "Hydrogen Manufacture by Electrolysis, Thermal Decomposition and Unusual Techniques", Noyes Data Corp., Park Ridge, 1978, p. 190). However, this diaphragm is not particularly inexpensive, and the voltage drop resulting from the diaphragm is comparable to that of asbestos diaphragms (see M.S. Casper).
Im Int.J. Hydrogen Energy 8, (1983), S. 81-83, wird ein anderer Separator für alkalische Wasserelektrolyse beschrieben, der aus mit polysulfongebundener Polyantimonsäure besteht, die als Ionenaustauscher wirkt. Dieser noch in Entwicklung begriffene Separator ist jedoch noch nicht verfügbar. Ein wesentlicher Nachteil desselben ist auf alle Fälle sein hoher elektrischer Membranwiderstand von 1,0 bis 0,8 Ωcm2 bei Zimmertemperatur.In the Int.J. Hydrogen Energy 8, (1983), pp. 81-83, describes another separator for alkaline water electrolysis, which consists of polysulfone-bound polyantimonic acid, which acts as an ion exchanger. This separator, which is still under development, is not yet available. A major disadvantage of the same is its high electrical membrane resistance of 1.0 to 0.8 Ωcm 2 at room temperature in any case.
Es wurden daher weitere Diaphragmen mit geringerem elektrischen Widerstand hergestellt, wie z.B. ein Diaphragma aus gesinterter Oxidkeramik (J. Fischer, H. Hofmann, G. Luft, H. Wendt:
- Seminar "Hydrogen as Energy Vector", Commission Europ. Comm., 3-4. Oct. 1978, Brüssel, S. 277 - 290). Dieses Diaphragma zeichnet sich zwar durch sehr gute Widerstandswerte aus (0,027 bis 0,27Ωcm2 bei 25 °C), die Herstellung ist jedoch nicht einfach und umfaßt
- i) die Erzeugung eines geeigneten Oxidmaterials, wie Zr02, BaTi03, K2Ti6013 usw., das als Hauptkomponente der porösen Schicht wirksam ist; und
- ii) ein Zusammensintern der Pulver bei hohen Temperaturen zwischen 1300 bis 1700 °C.
- Seminar "Hydrogen as Energy Vector", Commission Europ. Comm., 3-4. Oct. 1978, Brussels, pp. 277-290). This diaphragm is characterized by a lot good resistance values (0.027 to 0.27Ωcm 2 at 25 ° C), but the production is not easy and comprehensive
- i) the production of a suitable oxide material, such as Zr0 2 , BaTi0 3 , K 2 Ti 6 0 13 etc., which is effective as the main component of the porous layer; and
- ii) sintering the powders together at high temperatures between 1300 and 1700 ° C.
Ferner wurden poröse metallische Diaphragmen aus gesintertem Nickel vorgeschlagen (P. Perroud, G. Terrier: "Hydrogen Energy System", Proc. 2nd WHE Conference, Zürich 1978, S. 241). Diese haben einen sehr geringen elektrischen Widerstand und sind auch mechanisch stabil und preisgünstig. Der große Nachteil besteht allerdings darin, daß dieses Diaphragma ebenso wie die Elektroden auch elektronenleitend ist und bei kompakter Bauweise eine zu große Kurzschlußgefahr besteht.Porous metallic diaphragms made of sintered nickel have also been proposed (P. Perroud, G. Terrier: "Hydrogen Energy System", Proc. 2nd WHE Conference, Zurich 1978, p. 241). These have a very low electrical resistance and are also mechanically stable and inexpensive. The major disadvantage, however, is that this diaphragm, like the electrodes, is also electron-conductive and there is too great a risk of short-circuiting in a compact design.
Um diese störende Elektronenleitfähigkeit zu vermeiden, wurden von der Anmelderin poröse Nickeloxiddiaphragmen entwickelt (DE-OSen 29 27 566 und 30 31 064), die durch Oxidation von Sintermetall bei erhöhter Temperatur (DE-OS 29 27 566) oder einfacher durch oxidierendes Brennen einer auf einen Träger gepreßten Nickelpulverschicht (DE-OS 30 31 064) erhalten werden. Diese NiO-Diaphragmen besitzen hervorragende Eigenschaften als Separatoren für die alkalische Wasserelektrolyse.In order to avoid this disruptive electron conductivity, porous nickel oxide diaphragms have been developed by the applicant (DE-OSes 29 27 566 and 30 31 064), which are produced by oxidation of sintered metal at elevated temperature (DE-OS 29 27 566) or more simply by oxidizing firing a carrier pressed nickel powder layer can be obtained (DE-OS 30 31 064). These NiO diaphragms have excellent properties as separators for alkaline water electrolysis.
Die nach dem vereinfachten Herstellungsverfahren erhaltenen Diaphragmen wurden seitdem wiederholt bei den verschiedensten Elektrolyseversuchen angewandt und haben sich sehr gut bewährt. So wurde ihre Langzeitstabilität bei der alkalischen Wasserelektrolyse überprüft, wobei der bisher längste Versuch über 8000 Stunden(bei 120 °C) dauerte. Auch nach dieser Zeit waren die Diaphragmen noch intakt. Thermodynamische überlegungen legen allerdings die Vermutung nahe, daß diese Diaphragmen nach einer gewissen hinreichend langen Zeit auf der kathodischen Seite entweder durch die Kathode selbst oder durch den entstandenen Wasserstoff zu metallischem Nickel reduziert werden können. Diesem thermodynamisch bedingten Effekt steht nur eine kinetisch bedingte Hemmung entgegen, die nach einer bisher unbekannten Zeit nachlassen muß. Diese kann für die Zwecke einer Wasserelektrolyse durchaus hinreichen, es verbleibt jedoch eine gewisse'Unsicherheit.The after the simplified manufacturing process The diaphragms obtained have since been used repeatedly in a wide variety of electrolysis experiments and have proven themselves very well. Their long-term stability in alkaline water electrolysis was checked, the longest test to date lasting over 8000 hours (at 120 ° C). Even after this time, the diaphragms were still intact. Thermodynamic considerations suggest, however, that these diaphragms can be reduced to metallic nickel after a certain long enough time on the cathodic side either by the cathode itself or by the hydrogen formed. This thermodynamic effect is only opposed by a kinetic inhibition, which has to subside after a previously unknown time. This may be sufficient for the purposes of water electrolysis, but there remains a certain degree of uncertainty.
Daß diese Bedenken zurecht bestehen, zeigt folgender Versuch:
- Ein gemäß der DE-OS 30 31 064 hergestelltes Diaphragma wurde bei 200 °C einer Wasserstoffatmosphäre ausgesetzt. Dabei wurde eine allmähliche Reduktion des NiO zu Ni beobachtet, die nach
- 1500 Stunden sprunghaft zunahm, so daß nach
- 2000 Stunden das gesamte NiO vollständig reduziert war.
- A diaphragm manufactured according to DE-OS 30 31 064 was exposed to a hydrogen atmosphere at 200 ° C. A gradual reduction of the NiO to Ni was observed
- 1500 hours increased by leaps and bounds, so that after
- 2000 hours the total NiO was completely reduced.
Im Temperaturbereich von 140 bis 170 °C verläuft diese Reduktion zwar bedeutend langsamer, sie ist jedoch auch hier merklich, wie aus Fig. 1 zu erkennen ist: Nach 2000 Stunden sind vom-Diaphragma 7 % des im NiO enthaltenen Sauerstoffs entfernt. (Die Stabilisierung findet nach ca. 4500 h statt, wobei ca. 10 % des Sauerstoffs entfernt werden).In the temperature range from 140 to 170 ° C., this reduction proceeds significantly more slowly, but it is also noticeable here, as can be seen from FIG. 1: after 2000 hours, 7% of the oxygen contained in the NiO is removed from the diaphragm. (The stabilization takes place after approx. 4500 h, whereby approx. 10% of the oxygen is removed).
Einen solchen reduktiven Angriff durch Wasserstoff unterliegen keramische Diaphragmen aus thermodynamisch stabilen Oxidverbindungen, wie z.B. Zr02, BaTiO3, K2Ti6013 usw. (s.o.) zwar nicht, die Herstellung solcher Diaphragmen ist jedoch mit den bereits oben erwähnten Nachteilen, insbesondere sehr hohen Herstellungstemperaturen, verbunden, und sie werden in 10 N KOH bei erhöhter Temperatur mit der Zeit angegriffen.Such a reductive attack by hydrogen is not subject to ceramic diaphragms made of thermodynamically stable oxide compounds, such as Zr0 2 , BaTiO 3 , K 2 Ti 6 0 13 etc. (see above), but the manufacture of such diaphragms has the disadvantages mentioned above, in particular very high manufacturing temperatures, and they are attacked in 10 N KOH at elevated temperature with time.
Das "in situ" erzeugte NiO-Diaphragma gemäß der DE-OS 30 31 064 ist dagegen laugebeständig und seine Herstellung geht nicht nur von einer billigen Ausgangssubstanz aus, sondern bietet auch den entscheidenden technologischen Vorteil, daß die exotherme Reaktion 2 Ni + 02 → 2 Ni0 erst bei der Herstellung des Diaphragmas abläuft. Dadurch kommt es lokal zu einer beträchtlichen Temperaturerhöhung und die äußere Herstellungstemperatur kann lediglich bei 1000 °C liegen, was vorteilhaft ist. Dabei entfällt ferner - bedingt durch den Herstellungsprozeß (oxidierende Sinterung) - die Notwendigkeit, eine inerte Atmosphäre aufrechtzuerhalten, was ebenfalls eine deutliche Erleichterung bedeutet.The "in situ" NiO diaphragm according to DE-OS 30 31 064, on the other hand, is alkali-resistant and its manufacture not only starts from a cheap starting material, but also offers the decisive technological advantage that the exothermic reaction 2 Ni + 0 2 → 2 Ni0 only expires when the diaphragm is manufactured. This results in a considerable temperature increase locally and the external manufacturing temperature can only be 1000 ° C., which is advantageous. Due to the manufacturing process (oxidizing sintering), there is also no need to maintain an inert atmosphere, which is also a significant relief.
Der Erfindung liegt daher die Aufgabe zugrunde, die Reduktionsstabilität der Nickeloxiddiaphragmen unter den Bedingungen der alkalischen Wasserelektrolyse zu verbessern.The invention is therefore based on the object, the reduction stability of the nickel oxide diaphragms to improve under the conditions of alkaline water electrolysis.
Das zu diesem Zweck entwickelte erfindungsgemäße Diaphragma auf Nickeloxidbasis ist gekennzeichnet durch einen Gehalt an 0,5 bis 10 Gew.% Titan (in oxidierter Form; bezogen auf die Oxidmasse).The nickel oxide-based diaphragm according to the invention developed for this purpose is characterized by a content of 0.5 to 10% by weight of titanium (in oxidized form; based on the oxide mass).
Es hat sich nämlich überraschend gezeigt, daß die Reduktionsstabilität der NiO-Diaphragmen außergewöhnlich erhöht war, wenn dem Nickelpulver bei der Herstellung des Diaphragmas TiO2 in Mengen von 1 bis 20 Gew.% (bezogen auf die Summe von metallischem Nickel und Titandioxid) zugesetzt wurde. Besonders zweckmäßig war eine Titanbeimischung von 2 bis 10 Gew.%, insbesondere von 5 Gew.% (jeweils Titanoxid, bezogen auf die Summe von metallischem Nickel und TiG2).It has surprisingly been found that the reduction stability of the NiO diaphragms was exceptionally increased if TiO 2 was added to the nickel powder in the preparation of the diaphragm in amounts of 1 to 20% by weight (based on the sum of metallic nickel and titanium dioxide) . A titanium admixture of 2 to 10% by weight, in particular 5% by weight (in each case titanium oxide, based on the sum of metallic nickel and TiG 2 ) was particularly expedient.
Die Korngröße des zugemischten Pulvers sollte mit der des Nickelpulvers etwa vergleichbar oder kleiner sein, um eine gleichmäßige Verteilung des Titans über die Oxidmasse zu gewährleisten.The grain size of the admixed powder should be approximately comparable or smaller than that of the nickel powder in order to ensure a uniform distribution of the titanium over the oxide mass.
An Stelle von Titanoxid kann der Nickelpulvermasse bei der Herstellung des Diaphragmas auch Titan in metallischer Form oder auch als Verbindung zugemischt werden, die bei der oxidierenden Sinterbehandlung in Titanoxid übergehen. Gegebenenfalls kann auch ein bereits erzeugtes Nickeloxiddiaphragma mit einer Titanverbindung imprägniert werden, die durch Nachbrennen in oxidierte Form umgewandelt wird.Instead of titanium oxide, titanium powder can also be admixed to the nickel powder mass in the manufacture of the diaphragm, or else as a compound, which transform into titanium oxide during the oxidizing sintering treatment. If necessary, a nickel oxide diaphragm which has already been produced can also be impregnated with a titanium compound which is converted into oxidized form by afterburning.
Nachfolgend wird die Erfindung anhand von Beispielen näher erläutert, wobei auf die angefügten Zeichnungen Bezug genommen wird; es zeigen:
- Figur 1 Kurven für die Reduktionsanfälligkeit von Nickeloxiddiaphragmen in Wasserstoffatmosphäre bei Temperaturen von 140 bis 170 °C;
- Figur 2 Kurven für den Langzeitgewichtsverlust von keramischen Diaphragmen in 10 N KOH bei 120 °C und
- Figur 3 ein Fließbild, daß die einzelnen Verfahrensschritte bei einer Herstellung von erfindungsgemäßen Nickeloxiddiaphragmen wiedergibt.
- Figure 1 curves for the susceptibility to reduction of nickel oxide diaphragms in water atmosphere at temperatures from 140 to 170 ° C;
- Figure 2 curves for the long-term weight loss of ceramic diaphragms in 10 N KOH at 120 ° C and
- Figure 3 is a flow chart that shows the individual process steps in the manufacture of nickel oxide diaphragms according to the invention.
Es wurde ein keramisches Diaphragma auf NiO-Basis gemäß der DE-OS 30 31 064 unter Zusatz von TiO2 hergestellt. Diese Herstellung umfaßt die in Fig. 3 angegebenen Einzelschritte:
- Handelsübliches Carbonylnickelpulver (INCO-255; Korngröße 2 bis 3 µm) wurde
mit 10 Gew.% (bezogen auf die Pulvermischung, d.h. Ni + Ti02) handelsüblichem TiO2 der Fa. Merck gemischt und die Mischung in Aceton aufgeschlämmt auf eine glatte Oberfläche gleichmäßig verteilt. Nach Verdampfen des Suspensionsmittels wurde die so entstandene Schicht auf ein Ni-Netz (Drahtstärke 0,2 mm,Maschenweite 0,25 mm) kalt aufgewalzt. Die Verfahrensweise wurde wiederholt, um die zweite Seite des Nickelnetzes ebenfalls mit einer Pulverschicht zu versehen. - Die gleichmäßig verteilte Pulverschicht kann im übrigen auch ohne jedes Suspensionsmittel nach herkömmlichem Verfahren erhalten werden.
- Commercial carbonyl nickel powder (INCO-255; particle size 2 to 3 µm) was mixed with 10% by weight (based on the powder mixture, ie Ni + Ti0 2 ) of commercially available TiO 2 from Merck and the mixture was slurried in acetone evenly on a smooth surface distributed. After the suspension medium had evaporated, the layer formed in this way was cold-rolled onto a Ni mesh (wire thickness 0.2 mm, mesh size 0.25 mm). The procedure was repeated to also provide the second side of the nickel mesh with a powder layer. - The evenly distributed powder layer can also be obtained without any suspending agent by conventional methods.
Schließlich wurde die Anordnung ca. 20 Minuten lang in Luft bei 1050 °C gesintert.Finally, the assembly was sintered in air at 1050 ° C for about 20 minutes.
Die vorteilhaften physikalischen Eigenschaften des so entstandenen Diaphragmas, wie elektrischer Widerstand, mechanische Stabilität, Porosität oder Dicke waren im Vergleich zu denjenigen von Diaphragmen gemäß der DE-OS 30 31 064 keinesfalls verschlechtert.The advantageous physical properties of the diaphragm thus formed, such as electrical resistance, mechanical stability, porosity or thickness, were in no way deteriorated compared to those of diaphragms according to DE-OS 30 31 064.
Die chemische Stabilität war jedoch sehr stark verbessert, wie aus Fig. 1 und 2 ersichtlich ist: Die Sauerstoffabnahme in reiner Wasserstoffatmosphäre bei 140 bis 170 °C ist nicht mehr meßbar während der ersten 2000 h, was auf eine enorm erhöhte Reduktionsstabilität hindeutet. Im Vergleich dazu verliert z.B. ein Diaphragma aus reinem NiO in 2000 Std. 7 % des Sauerstoffs und sogar ein mit A1203-Zusatz stabilisiertes Diaphragma verliert in der gleichen Zeit immer noch ca. 1,5 % des Sauerstoffgehaltes. Analog dazu ist auch die bereits an sich ausgezeichnete chemische Stabilität in heißer KOH weiter erhöht: Wie Fig.2 zeigt, beträgt der Gesamtgewichtsverlust nach 2000 Stunden in 10 N KOH bei 120 °C nur 0,3 %. Im Vergleich dazu verliert ein reines NiO-Diaphragma 0,8 %, ein BaTi03-Diaphragma 2 % und ein mit 5 % Al2O3 gemischtes Diaphragma 8 % des Gesamtgewichtes, was dem A1203 zuzuschreiben ist.The chemical stability was, however, greatly improved, as can be seen from FIGS. 1 and 2: The decrease in oxygen in a pure hydrogen atmosphere at 140 to 170 ° C. can no longer be measured during the first 2000 h, which indicates an enormously increased reduction stability. In comparison, for example, a diaphragm made of pure NiO loses 7% of the oxygen in 2000 hours and even a diaphragm stabilized with
Diese positive Wirkung der Zugabe von Titanoxid macht sich bereits ab 1 bis 2 Gew.% TiO2 bemerkbar.This positive effect of the addition of titanium oxide is noticeable from 1 to 2% by weight of TiO 2 .
Dem Ni-Pulver wurden vor dem Aufschlämmschritt 8 Gew.% metallisches Ti (bezogen auf die Pulvermischung) von annähernd gleicher Korngröße wie Ni zugegeben. Die nachfolgenden Hertellungsschritte waren die gleichen wie in Beispiel 1. Nach der oxidierenden Sinterung lagen sowohl Nickel als auch Titan in oxidischer Form vor. Dieses Diaphragma besaß die gleichen Eigenschaften wie das von Beispiel 1 in Bezug auf die Reduzierbarkeit in H2-Atmosphäre.Before the slurrying step, 8% by weight of metallic Ti (based on the powder mixture) of approximately the same grain size as Ni was added to the Ni powder. The subsequent production steps were the same as in Example 1. After the oxidizing sintering, both nickel and titanium were present in oxidic form. This diaphragm had the same properties as that of Example 1 with respect to the reducibility in H 2 atmosphere.
Zum Ni-Pulver wurden vor dem Aufschlämmen 50 % TiO2 zugegeben. Im übrigen entsprach die Herstellung derjenigen von Beispiel 1. Das so hergestellte Diaphragma zeigte in 10 N KOH bei 120 °C bereits nach 500 Stunden einen Gewichtsverlust von insgesamt 10 %.50% TiO 2 was added to the Ni powder before slurrying. Otherwise, the preparation corresponded to that of Example 1. The diaphragm produced in this way showed a weight loss of 10% after only 500 hours in 10 N KOH at 120 ° C.
Daraufhin wurde dieser Versuch abgebrochen und festgestellt, daß mit einer solchen Ti02-Beimischung erzeugte NiO-Diaphragmen für die alkalische Wasserelektrolyse ungeeignet sind, auch wenn die Reduktionseigenschaften (gemessen als Gewichtsabnahme in Wasserstoffatmosphäre bei 140 bis 170 °C) sehr gut sind und denjenigen eines Diaphragmas gemäß Beispiel 1 nicht nachstehen.Thereupon, this experiment was stopped and it was found that NiO diaphragms produced with such a TiO 2 admixture are unsuitable for alkaline water electrolysis, even if the reduction properties (measured as weight loss in a hydrogen atmosphere at 140 to 170 ° C) are very good and one Do not lag behind the diaphragm according to Example 1.
Diese negative Wirkung einer zu hohen Ti02-Zugabe macht sich bereits ab 20 Gew.% Ti02 (entspricht 10 Gew.% Ti, bezogen auf die oxidierte Masse) bemerkbar.This negative effect of an excessively high addition of Ti0 2 is noticeable even from 20% by weight of Ti0 2 (corresponds to 10% by weight of Ti, based on the oxidized mass).
Claims (5)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AT84105869T ATE31432T1 (en) | 1983-05-24 | 1984-05-23 | NICKEL OXIDE BASED DIAPHRAGM AND METHOD OF MAKING THE SAME. |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE3318758A DE3318758C2 (en) | 1983-05-24 | 1983-05-24 | Nickel oxide based diaphragm and method of making the same |
DE3318758 | 1983-05-24 |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0126490A1 true EP0126490A1 (en) | 1984-11-28 |
EP0126490B1 EP0126490B1 (en) | 1987-12-16 |
Family
ID=6199718
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP84105869A Expired EP0126490B1 (en) | 1983-05-24 | 1984-05-23 | Diaphragm based on nickel oxide and process for its manufacture |
Country Status (9)
Country | Link |
---|---|
US (1) | US4559124A (en) |
EP (1) | EP0126490B1 (en) |
JP (1) | JPS59229489A (en) |
AT (1) | ATE31432T1 (en) |
BR (1) | BR8402480A (en) |
CA (1) | CA1254857A (en) |
DE (2) | DE3318758C2 (en) |
NO (1) | NO161628C (en) |
ZA (1) | ZA843921B (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0339728A1 (en) * | 1988-04-23 | 1989-11-02 | Metallgesellschaft Ag | Process and apparatus for manufacturing diaphragms |
WO2021043578A1 (en) | 2019-09-05 | 2021-03-11 | Thyssenkrupp Uhde Chlorine Engineers Gmbh | Cross-flow water electrolysis |
Families Citing this family (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3424203A1 (en) * | 1984-06-30 | 1986-01-16 | Kernforschungsanlage Jülich GmbH, 5170 Jülich | DIAPHRAGMA FOR ALKALINE ELECTROLYSIS AND METHOD FOR PRODUCING THE SAME |
DE8517106U1 (en) * | 1985-06-12 | 1985-08-01 | Kernforschungsanlage Jülich GmbH, 5170 Jülich | Diaphragm for alkaline electrolysis |
US7329332B2 (en) * | 2004-08-25 | 2008-02-12 | Ppg Industries Ohio, Inc. | Diaphragm for electrolytic cell |
US7618527B2 (en) * | 2005-08-31 | 2009-11-17 | Ppg Industries Ohio, Inc. | Method of operating a diaphragm electrolytic cell |
US8460536B2 (en) * | 2006-01-19 | 2013-06-11 | Eagle Controlled 2 Ohio Spinco, Inc. | Diaphragm for electrolytic cell |
CN102400139A (en) * | 2010-09-15 | 2012-04-04 | 鸿富锦精密工业(深圳)有限公司 | Film coated piece and manufacturing method thereof |
ITMI20131804A1 (en) * | 2013-10-30 | 2015-05-01 | Intecna S R L | PROCESS AND APPARATUS FOR THE CONTINUOUS PRODUCTION OF FERRATI ALKALINI, IN PARTICULAR OF FERRATO DI SODIO |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
AT343146B (en) * | 1974-05-24 | 1978-05-10 | Ici Ltd | ELECTROCHEMICAL DIAPHRAGIC CELL AND METHOD FOR THE PRODUCTION THEREOF |
DE2927566A1 (en) * | 1979-07-07 | 1981-01-08 | Kernforschungsanlage Juelich | DIAPHRAGMA FOR ALKALINE WATER ELECTROLYSIS AND METHOD FOR PRODUCING THE SAME AND THE USE THEREOF |
DE3031064A1 (en) * | 1980-08-16 | 1982-03-04 | Kernforschungsanlage Jülich GmbH, 5170 Jülich | POROESES OXIDE DIAPHRAGMA FOR ALKALINE ELECTROLYSIS, THEIR PRODUCTION AND USE |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
IT1002909B (en) * | 1973-02-17 | 1976-05-20 | Deutsche Automobilgesellsch | MEMBRANE FOR THE SEPARATION OF HYDRO GENO FROM MIXTURES OF GAS CONTAINING HYDROGEN |
IT1115372B (en) * | 1977-07-15 | 1986-02-03 | Oronzio De Nora Impianti | TWO-STAGE CERAMIC MEMBRANES FOR ELECTROLYTIC CELLS |
US4394224A (en) * | 1980-04-24 | 1983-07-19 | British Aerospace Public Limited Company | Treatment of titanium prior to bonding |
DE3108255C2 (en) * | 1981-03-05 | 1986-05-07 | Kernforschungsanlage Jülich GmbH, 5170 Jülich | Assembly unit for electrolysis cells for alkaline water electrolysis and process for producing the same |
DE3109183C2 (en) * | 1981-03-11 | 1983-05-11 | BOMIN Bochumer Mineralöl GmbH & Co, 4630 Bochum | Highly porous electrode hot-pressed from nickel powder for alkaline water electrolysers |
-
1983
- 1983-05-24 DE DE3318758A patent/DE3318758C2/en not_active Expired
-
1984
- 1984-05-23 AT AT84105869T patent/ATE31432T1/en not_active IP Right Cessation
- 1984-05-23 EP EP84105869A patent/EP0126490B1/en not_active Expired
- 1984-05-23 BR BR8402480A patent/BR8402480A/en not_active IP Right Cessation
- 1984-05-23 DE DE8484105869T patent/DE3468129D1/en not_active Expired
- 1984-05-23 CA CA000454981A patent/CA1254857A/en not_active Expired
- 1984-05-23 NO NO842048A patent/NO161628C/en unknown
- 1984-05-24 US US06/613,877 patent/US4559124A/en not_active Expired - Fee Related
- 1984-05-24 ZA ZA843921A patent/ZA843921B/en unknown
- 1984-05-24 JP JP59103772A patent/JPS59229489A/en active Pending
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
AT343146B (en) * | 1974-05-24 | 1978-05-10 | Ici Ltd | ELECTROCHEMICAL DIAPHRAGIC CELL AND METHOD FOR THE PRODUCTION THEREOF |
DE2927566A1 (en) * | 1979-07-07 | 1981-01-08 | Kernforschungsanlage Juelich | DIAPHRAGMA FOR ALKALINE WATER ELECTROLYSIS AND METHOD FOR PRODUCING THE SAME AND THE USE THEREOF |
DE3031064A1 (en) * | 1980-08-16 | 1982-03-04 | Kernforschungsanlage Jülich GmbH, 5170 Jülich | POROESES OXIDE DIAPHRAGMA FOR ALKALINE ELECTROLYSIS, THEIR PRODUCTION AND USE |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0339728A1 (en) * | 1988-04-23 | 1989-11-02 | Metallgesellschaft Ag | Process and apparatus for manufacturing diaphragms |
DE3813743A1 (en) * | 1988-04-23 | 1989-11-02 | Metallgesellschaft Ag | METHOD AND DEVICE FOR PRODUCING DIAPHRAGMS |
WO2021043578A1 (en) | 2019-09-05 | 2021-03-11 | Thyssenkrupp Uhde Chlorine Engineers Gmbh | Cross-flow water electrolysis |
Also Published As
Publication number | Publication date |
---|---|
NO161628B (en) | 1989-05-29 |
EP0126490B1 (en) | 1987-12-16 |
NO161628C (en) | 1989-09-06 |
NO842048L (en) | 1984-11-26 |
US4559124A (en) | 1985-12-17 |
DE3318758A1 (en) | 1984-11-29 |
CA1254857A (en) | 1989-05-30 |
ATE31432T1 (en) | 1988-01-15 |
JPS59229489A (en) | 1984-12-22 |
DE3468129D1 (en) | 1988-01-28 |
ZA843921B (en) | 1986-01-29 |
BR8402480A (en) | 1985-04-02 |
DE3318758C2 (en) | 1985-06-13 |
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