US4176094A
Expired / Lapsed
US
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Method of making stoichiometric lead and bismuth pyrochlore compounds using an alkaline medium
Assignee: ExxonMobil Technology and Engineering Co
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Filing: 1978-08-31
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Granted: 1979-11-27
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Expires: 1998-08-31
Abstract
Abstract A liquid solution method of preparing electrically conductive pyrochlore compounds having the formula: A2B2O7-y is disclosed wherein A is selected from lead, bismuth and mixtures thereof, B is selected from ruthenium, iridium and mixtures thereof, and 0</=y</=1. The method involves reacting A and B cations to yield a pyrochlore oxide by precipitation of A and B cations from an aqueous solution source of these cations in a liquid alkaline medium having a pH of at least about 13.5 in the presence of an oxygen source sufficient to complete the desired stoichiometry, at a temperature below about 200 DEG C. for a sufficient time for reaction to occur.
Inventors
- 👤 Harold S. Horowitz
- 👤 John M. Longo
- 👤 Joseph T. Lewandowski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 23:10
CPC Classifications
C; C01; C01G; C01G55/00; C25; C25B; C25B11/00; C25B11/04; C25B11/042; C25B11/047; H; H01; H01B; H01B1/00; H01B1/06; H01B1/08; H01M; H01M12/00; H01M12/04; H01M12/06; H01M4/00; H01M4/86; H01M4/90; H01M4/9016
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
101 words
A method of preparing compounds having the formula: A.sub.2 B.sub.2 O.sub.7-y wherein A is selected from the group consisting of lead, bismuth and mixtures thereof, wherein B is selected from the group consisting of ruthenium, iridium and mixtures thereof, wherein y is a value such that O≦y≦1, comprising: reacting A cations and B cations, in approximately stoichiometric amounts, from an aqueous solution source of these cations in a liquid alkaline medium having a pH of at least about 13.5 in the presence of an oxygen source at a temperature below about 200° C. for a sufficient time for reaction to occur.
Claim 2
Independent Claim
101 words
A method of preparing compounds having the formula: A.sub.2 B.sub.2 O.sub.7-y wherein A is selected from the group consisting of lead, bismuth and mixtures thereof, wherein B is selected from the group consisting of ruthenium, iridium and mixtures thereof, wherein y is a value such that O≦y≦1, comprising: reacting A cations and B cations, in approximately stoichiometric amounts, from an aqueous solution source of these cations in a liquid alkaline medium having a pH of at least about 13.5 in the presence of an oxygen source at a temperature below about 200° C. for a sufficient time for reaction to occur.
Claim 3
Dependent Claim
72 words
The method of claim 1 wherein said aqueous solution source contains A source material selected from the group consisting of lead nitrate, lead oxide, lead chloride, lead acetate, lead carbonate, lead citrate, lead oxalate, bismuth nitrate, bismuth oxide, bismuth chloride, bismuth oxalate, bismuth oxychloride and mixtures thereof and B source material selected from the group consisting of ruthenium chloride, ruthenium nitrate, ruthenium nitrosyl nitrite, iridium chloride, iridium hydroxide and iridium oxalic acid.
Claim 4
Dependent Claim
19 words
The method of claim 2 wherein said liquid alkaline medium is an aqueous basic solution of alkali metal hydroxide.
Claim 5
Dependent Claim
30 words
The method of claim 3 wherein said aqueous basic solution contains a base selected from the group consisting of sodium hydroxide, rubidium hydroxide, cesium hydroxide, potassium hydroxide and mixtures thereof.
Claim 6
Dependent Claim
22 words
The method of claim 4 wherein said reacting is performed within the temperature range of about 10° C. to about 100° C.
Claim 7
Dependent Claim
18 words
The method of claim 5 wherein said pH is within the range of about 14 to about 15.5.
Claim 8
Dependent Claim
22 words
The method of claim 6 wherein said reacting is performed within the temperature range of about 50° C. to about 80° C.
Claim 9
Dependent Claim
31 words
The method of claim 1 wherein, during said reacting, sufficient fresh alkaline medium is added to the reaction to retard formation of A cation-rich compound and to facilitate the desired reaction.
Claim 10
Dependent Claim
20 words
The method of claim 1 wherein, after said reacting, the product obtained is subjected to leaking to remove undesired impurities.
Claim 11
Dependent Claim
9 words
The method of claim 1 wherein A is lead.
Claim 12
Dependent Claim
33 words
The method of claim 10 wherein said aqueous solution source contains as A source material lead nitrate and contains B source material selected from the group consisting of ruthenium nitrate and iridium chloride.
Claim 13
Dependent Claim
19 words
The method of claim 11 wherein said reacting alkaline medium is an aqueous basic solution of alkali metal hydroxide.
Claim 14
Dependent Claim
30 words
The method of claim 12 wherein said aqueous basic solution contains a base selected from the group consisting of sodium hydroxide, rubidium hydroxide, cesium hydroxide, potassium hydroxide and mixtures thereof.
Claim 15
Dependent Claim
22 words
The method of claim 13 wherein said reacting is performed within the temperature range of about 10° C. to about 100° C.
Claim 16
Dependent Claim
18 words
The method of claim 14 wherein said pH is within the range of about 14 to about 15.5.
Claim 17
Dependent Claim
22 words
The method of claim 15, wherein said reacting is performed within the temperature range of about 50° C. to about 80° C.
Claim 18
Dependent Claim
31 words
The method of claim 10 wherein, during said reacting, sufficient fresh alkaline medium is added to the reaction to retard formation of A cation-rich compound and to facilitate the desired reaction.
Claim 19
Dependent Claim
20 words
The method of claim 10 wherein, after said reacting, the product obtained is subjected to leaking to remove undesired impurities.
Claim 20
Dependent Claim
9 words
The method of claim 1 wherein A is bismuth.
Claim 21
Dependent Claim
32 words
The method of claim 19 wherein said aqueous solution source contains as A source bismuth nitrate and contains B source material selected from the group consisting of ruthenium nitrate and iridium chloride.
Claim 22
Dependent Claim
19 words
The method of claim 20 wherein said liquid alkaline medium is an aqueous basic solution of alkali metal hydroxide.
Claim 23
Dependent Claim
30 words
The method of claim 21 wherein said aqueous basic solution contains a base selected from the group consisting of sodium hydroxide, rubidium hydroxide, cesium hydroxide, potassium hydroxide and mixtures thereof.
Claim 24
Dependent Claim
22 words
The method of claim 22 wherein said reacting is performed within the temperature range of about 10° C. to about 100° C.
Claim 25
Dependent Claim
18 words
The method of claim 23 wherein said pH is within the range of about 14 to about 15.5.
Claim 26
Dependent Claim
22 words
The method of claim 24 wherein said reacting is performed within the temperature range of about 50° C. to about 80° C.
Claim 27
Dependent Claim
31 words
The method of claim 19 wherein, during said reacting, sufficient fresh alkaline medium is added to the reaction to retard formation of A cation-rich compound and to facilitate the desired reaction.
Claim 28
Dependent Claim
20 words
The method of claim 19 wherein, after said reacting, the product obtained is subjected to leaking to remove undesired impurities.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-11-26 | 1983-05-28 | 1983-11-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-11-26 | 1987-05-28 | 1987-11-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-11-26 | 1991-05-28 | 1991-11-27 | $7700.00 | Window Closed / Lapsed |