Joseph W Lewandowski

US Patent:

42038715, May 20, 1980

Filed:

Nov 1, 1978

Appl. No.:

5/956744

Inventors:

Harold S. Horowitz - Clark NJ
John M. Longo - New Providence NJ
Joseph T. Lewandowski - Middlesex NJ

Assignee:

Exxon Research & Engineering Co. - Florham Park NJ

International Classification:

H01B 108

US Classification:

252518

Abstract:

A liquid solution method of preparing electrically conductive pyrochlore compounds having the formula: A. sub. 2 [B. sub. 2-x A. sub. x ]O. sub. 7-y is disclosed wherein A is selected from lead, bismuth and mixtures thereof, B is selected from ruthenium, iridium and mixtures thereof, 0. ltoreq. times. ltoreq. 1. 0 and 0. ltoreq. y. ltoreq. 1. The method involves reacting A and B cations to yield a pyrochlore oxide by precipitation of A and B cations in a liquid medium having a pH which is equal to or greater than 4. 5, but less than 13. 5, in the presence of an oxygen source at a temperature below about 200. degree. C. for a time sufficient for reaction to occur. In those instances in which amorphous reaction products are obtained, these amorphous reaction products are subsequently heat treated at a temperature of about 200. degree. C. to about 600. degree. C. for a time sufficient to convert amorphous reaction products to crystalline pyrochlore(s).

US Patent:

41295250, Dec 12, 1978

Filed:

Dec 2, 1977

Appl. No.:

5/856648

Inventors:

Harold S. Horowitz - Clark NJ
John M. Longo - New Providence NJ
Joseph T. Lewandowski - Middlesex NJ

Assignee:

Exxon Research & Engineering Co. - Florham Park NJ

International Classification:

C01G 5500

US Classification:

252518

Abstract:

A liquid solution method of preparing electrically conductive pyrochlore compounds of high surface area, having the formula: A. sub. 2 [B. sub. 2-x A. sub. x ]0. sub. 7-y is disclosed wherein A is selected from lead, bismuth and mixtures thereof, B is selected from ruthenium, iridium and mixtures thereof, 0 < x. ltoreq. 1. 0 and 0. ltoreq. y. ltoreq. 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 at a temperature below about 200. degree. C for a sufficient time for reaction to occur.

US Patent:

41927800, Mar 11, 1980

Filed:

Nov 1, 1978

Appl. No.:

5/956743

Inventors:

Harold S. Horowitz - Clark NJ
John M. Longo - New Providence NJ
Joseph T. Lewandowski - Middlesex NJ

Assignee:

Exxon Research & Engineering Co. - Florham Park NJ

International Classification:

H01B 108

US Classification:

252518

Abstract:

A liquid solution method of preparing electrically conductive pyrochlore compounds of high surface area, having the formula: A. sub. 2 [B. sub. 2-x A. sub. x ]O. sub. 7-y is disclosed wherein A is selected from lead, bismuth and mixtures thereof, B is selected from ruthenium, iridium and mixtures thereof, 0

US Patent:

42254698, Sep 30, 1980

Filed:

Nov 1, 1978

Appl. No.:

5/956745

Inventors:

Harold S. Horowitz - Clark NJ
John M. Longo - New Providence NJ
Joseph T. Lewandowski - Middlesex NJ

Assignee:

Exxon Research & Engineering Co. - Florham Park NJ

International Classification:

H01B 106

US Classification:

252518

Abstract:

A method of preparing electrically conductive pyrochlore compounds having the formula: A. sub. 2 [B. sub. 2-x A. sub. x ]0. sub. 7-y is disclosed wherein A is selected from lead, bismuth and mixtures thereof, B is selected from ruthenium, iridium and mixtures thereof, O. ltoreq. x. ltoreq. 1. 0 and 0. ltoreq. y. ltoreq. 1. The method involves reacting A and B cations using at least one solid reactant 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. degree. C. for a sufficient time for reaction to occur.

US Patent:

41637062, Aug 7, 1979

Filed:

Dec 2, 1977

Appl. No.:

5/856628

Inventors:

Harold S. Horowitz - Clark NJ
John M. Longo - New Providence NJ
Joseph T. Lewandowski - Middlesex NJ

Assignee:

Exxon Research & Engineering Co. - Florham Park NJ

International Classification:

C25B 900
C25B 1104
C01G 2900
H01B 108

US Classification:

204242

Abstract:

Novel bismuth-rich pyrochlore-type compounds are described having the formula: Bi. sub. 2 [M. sub. 2-x Bi. sub. x ]O. sub. 7-y wherein M is selected from the group consisting of Ru, Ir and mixtures thereof and wherein x is greater than zero and less than or equal to about 1. 0 and y is greater than or equal to zero and less than or equal to about 1. Electrochemical devices containing these compounds as electrocatalyst materials for oxygen electrodes are also described.

US Patent:

41760948, Nov 27, 1979

Filed:

Aug 31, 1978

Appl. No.:

5/938374

Inventors:

Harold S. Horowitz - Clark NJ
John M. Longo - New Providence NJ
Joseph T. Lewandowski - Middlesex NJ

Assignee:

Exxon Research & Engineering Co. - Florham Park NJ

International Classification:

H01B 108

US Classification:

252518

Abstract:

A liquid solution method of preparing electrically conductive pyrochlore compounds having the formula: A. sub. 2 B. sub. 2 O. sub. 7-y is disclosed wherein A is selected from lead, bismuth and mixtures thereof, B is selected from ruthenium, iridium and mixtures thereof, and 0. ltoreq. y. ltoreq. 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. degree. C. for a sufficient time for reaction to occur.