Abstract: An improved process for calcination and activation of a catalyst containing mixed oxides of vanadium and phosphorus (V/P/O) comprising the steps of calcining a hydrated V/P/O or V/P/O- SiO.sub.2 catalyst precursor at a temperature range of 375.degree. to 400.degree. C. for sufficient time to dehydrate said catalyst precursor while simultaneously and continuously controlling the oxygen level such as to maintain the Vox in the range of 3.825 to 4.175; and then activating the dehydrated catalyst precursor by further heating at a range of 340.degree. to 500.degree. C. in the presence of a gaseous atmosphere containing n-butane at a partial pressure not exceeding 0.20 atm while simultaneously and continuously controlling the oxygen level such as to maintain the Vox in the range of 3.95 to 4.15. Such a V/P/O catalyst is useful in the preparation of maleic anhydride from n-butane.

Abstract: An improved process for selective vapor phase oxidation of n-butane to maleic anhydride involving the use of a recirculating solids reactor having a reaction zone and a catalyst regeneration zone wherein n-butane is converted to maleic acid in the reaction zone by use of a vanadium/phosphorous oxide (V/P/O) catalyst in oxidized form and the reduced vanadium/phosphorous oxide catalyst is regenerated by contact with oxygen in the regeneration zone. Replenishment of the inherent catalyst losses associated with the catalyst recycling process is accomplished by adding to the catalyst in the regeneration zone vanadium/phosphorous oxide catalyst precursor at a rate of addition that effectuates in situ calcination and activation of the vanadium/phosphorous oxide catalyst precursor while simultaneously maintaining the desired operating temperature of the n-butane to maleic anhydride conversion reaction. Such a process is useful in maintaining the high operating capacity of the reactor over an extended period of time.

Abstract: An improved process for preparing a superconducting composition having the formula M.sub.W A.sub.E Cu.sub.V O.sub.K wherein M is selected from the group consisting of Bi, Tl, Y, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm Yb and Lu; A is at least one alkaline earth metal selected from the group consisting of Ba, Ca and Sr; x is at least 6; w is at least 1; z is at least 2 and v is at least 1; said composition having a superconducting transition temperature of above 77K, preferably above about 90 K; said process consisting essentially of (a) forming a suspension having an M:A:Cu atomic ratio of w:z:v by mixing A(OH).sub.2, AO or AO.sub.2 and M.sub.2 O.sub.3 with an aqueous solution of cupric carboxylate or cupric nitrate at a temperature from about 50.degree. C. to about 100.degree. C., or mixing A(OH).sub.2 with an aqueous solution of Cu carboxylate, nitrate or a mixture thereof and M carboxylate, nitrate or a mixture thereof at a temperature from about 50.degree. C. to about 100.degree. C.

Abstract: There is disclosed an improved process for preparing a superconducting composition having the formula M.sub.w A.sub.z Cu.sub.v O.sub.x wherein M is selected from the group consisting if Bi, Tl, Y, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm Yb and Lu; A is at least one alkaline earth metal selected from the group consisting of Ba, Ca and Sr; x is at least 6; w is at least 1; z is at least 2 and v is at least 1; said composition having a superconducting transition temperature of above 77 K, preferably above about 90 K; said process consisting essentially of (a) forming a suspension having an M:A:Cu atomic ratio of w:z:v by mixing A(OH).sub.2, AO or AO.sub.2 and M.sub.2 O.sub.3 with an aqueous solution of cupric carboxylate or cupric nitrate at a temperature from about 50.degree. C. to about 100.degree. C., or mixing A(OH).sub.2 with an aqueous solution of Cu carboxylate, nitrate or a mixture thereof and M carboxylate, nitrate or a mixture thereof at a temperature from about 50.degree. C. to about 100.degree. C.

Abstract: A process for preparing the superconductive material MBa.sub.2 Cu.sub.3 O.sub.x, M being, inter alia, yttrium and x being from about 6.5-7 and a precursor material MBa.sub.2 Cu.sub.3 O.sub.y, y being from about 6-6.5, by controlled heating and cooling in a controlled atmosphere.

Abstract: A method of preparing electrically conductive pyrochlore compounds of high surface area and unagglomerated form, having the formulaA.sub.2 [B.sub.2-x A.sub.x ]O.sub.7-yis 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 (1) synthesizing the pyrochlores in an aqueous alkaline reaction medium having a pH of at least about 12.0 and in the presence of an oxygen source (2) displacing the reaction medium with water, (3) atomizing the resultant slurry and (4) freeze drying the resultant product. The pyrochlore compounds thus prepared have a variety of applications including use as oxygen electrodes in electro-chemical devices.

Abstract: A method for electrocatalytically reacting various oxidizable organic compounds by introducing current by means of an anode into an electrolyte of a cell containing the oxidizable organic compound. The anode comprises an electrocatalyst material which has at least one compound of the formula:A.sub.2 [B.sub.2-x B'.sub.x ]O.sub.7-ywherein A is selected from any of the pyrochlore structure metal cations in a group consisting of: Pb, Bi, and Tl, wherein B' is selected from any of the pyrochlore structure metal cations in a group consisting of Pb, Bi, Tl, and Sn; wherein B is a pyrochlore structure metal cation at least a major portion of which is selected from a group consisting of at least one of: Ru, Rh, Ir, and Os, wherein y is equal to or greater than zero and equal to or less than one; and wherein x is equal to or less than one and equal to or greater than zero.

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-yis 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.

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-yis 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).

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-yis disclosed wherein A is selected from lead, bismuth and mixtures thereof, B is selected from ruthenium, iridium and mixtures thereof, 0<.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 from an aqueous solution source of these cations in a liquid alkaline medium having a pH of at least about 10.0 in the presence of an oxygen source, and in the presence of a reaction-enhancing anodic potential, at a temperature below about 200.degree. C. for a sufficient time for reaction to occur.

Abstract: A liquid solution method of preparing electrically conductive pyrochlore compounds having the formula:A.sub.2 B.sub.2 O.sub.7-yis 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.

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-ywherein 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 1.0. Electrochemical devices containing these compounds as electrocatalyst materials for oxygen electrodes are also described.

Abstract: An electrochemical device is described which has an oxygen electrode which contains a pyrochlore type electrocatalyst material. This electrocatalyst material is one or more electrically conductive pyrochlore compounds selected from the compounds of the following formula:A.sub.2 B.sub.2 O.sub.7-y (1)wherein A is any of the known pyrochlore structure metal cations, B is a pyrochlore structure metal cation at least a major portion of which is selected from the group consisting of one or more of Ru, Rh, Ir, Os, Pt, Ru-Pb mixtures and Ir-Pb mixtures, and wherein O.ltoreq.y.ltoreq.1.0. Desirably, A is a pyrochlore structure metal cation at least a major portion of which is selected from the group consisting of one or more of Pb, Bi and T1. A preferred group of pyrochlore compounds which are included in the above formula are those having the following formula:Pb.sub.2 [M.sub.2-x Pb.sub.x ]O.sub.7-y (2)wherein M is selected from the group consisting of Ru and Ir, wherein O.ltoreq.X.ltoreq.1.2 and O.ltoreq.y.ltoreq.1.

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-yis 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.

Abstract: Novel lead-rich pyrochlore type compounds are described having the formula:Pb.sub.2 [M.sub.2-x Pb.sub.x ]O.sub.7-ywherein M is selected from the group consisting of Ru, Ir and mixtures thereof and wherein x is greater than 0 and less than or equal to about 1.2 and y is greater than or equal to 0 and less than or equal to about 1.0. A method of synthesizing these compounds is also described. The method involves the solid state reaction of a lead source and a ruthenium source and/or an iridium source at temperatures below about 600.degree. C in an oxygen-containing environment.

Abstract: Mixed metal oxides of the formula CaMn.sub.3 O.sub.6, CaMn.sub.4 O.sub.8 and CaMn.sub.7 O.sub.12 are disclosed. They are useful in electrochemical processes. CaMn.sub.3 O.sub.6 is a mixed valence composition whose formula may be written as Ca[Mn.sub.2.sup.3+ Mn.sup.4+ ]O.sub.6. The compound is stable in H.sub.2 to about 400.degree. C. and in oxygen to approximately 925.degree. C. CaMn.sub.4 O.sub.8 is also a mixed valence composition whose formula may be written Ca[Mn.sub.2.sup.3+ Mn.sub.2.sup.4+ ]O.sub.8. This compound is stable in H.sub.2 to about 250.degree. C. and in O.sub.2 to about 900.degree. C. CaMn.sub.7 O.sub.12 is a mixed valence composition whose formula may be written as Ca[Mn.sup.4+ Mn.sub.6.sup.3+ ]O.sub.12. The compound is stable in H.sub.2 to about 500.degree. C. and in oxygen to approximately 950.degree. C.

Abstract: A process for the preparation of high surface area mixed metal oxides by decomposition of solid solutions of carbonates possessing the calcite structure. Oxide compounds comprising mixtures of Ca, Mn, Fe, Co, Ni, Zn, Cd and Mg can be prepared by this method. For example, CaMnO.sub.3 with a surface area of 11 m.sup.2 /g useful as a battery cathode, has been prepared by the instant method, that is, by decomposition of a CaMn(CO.sub.3).sub.2 precursor.The mixed metal carbonate solid solutions which are used as precursors for the preparation of the mixed metal oxides are themselves prepared by the precipitation from solution of the appropriate metal ions by the addition of an excess of a carbonate ion source (such as (NH.sub.4).sub.2 CO.sub.3). The metal-ion ratio in this solution is adjusted so that the resulting precipitate has the same stoichiometry as the desired oxide.

Abstract: A new low temperature layered manganese compound of the formula Ca.sub.2 Mn.sub.3 O.sub.8 has unexpectedly been synthesized in pure form. The unit cell dimensions of this new compound have been determined by X-ray diffraction and reveal that the compound is monoclinic with lattice parameters of a=11.02 A, b=5.85 A, c=4.94 A, .alpha.=90.degree., .beta.=109.80.degree., .gamma.=90.degree.. The structure consists of pseudohexagonal Mn.sup.4+ sheets with similar oxygen sheets on either side, giving a distorted octahedral coordination to the Mn.sup.4+. Every fourth Mn.sup.4+ is missing in these layers, so their composition is Mn.sub.3 O.sub.8 with chains of coordination octahedra linked by common edges (rutile type arrangement). The Ca ions are situated between the Mn.sub.3 O.sub.8 layers.This new Ca.sub.2 Mn.sub.3 O.sub.