摘要:
Solid mesoporous crystalline composition of a pyrophosphate-phosphate of a tetravalent metal, with a high surface area and narrow distribution of the mesopores, having formula (I):M(P.sub.2 O.sub.7).sub.1-z (HPO.sub.4).sub.2z (I)wherein: M is a tetravalent metal and z varies from 0.05 to 0.25.The process for its production is described together with its uses.
摘要翻译:具有式(I):M(P 2 O 7)1-z(HPO 4)2 z(I)的具有高表面积和中孔分布较窄的四价金属焦磷酸盐 - 磷酸盐的固体介孔结晶组合物其中:M为 四价金属和z在0.05至0.25之间变化。 描述其生产过程及其用途。
摘要:
A solid-state sensor for determining the concentration of gases which can react with hydrogen, in particular, of oxygen, which includes a solid-state proton conductor into contact: on the one side, with a reference electrode, constituted in its turn by a metal hydride or a metal alloy, and on the other side with an electrode which catalyses the reaction of the gas to be detected, with said sensor being connected with a power feed system which supplies current or voltage impulses, and with a system which detects the value of potential after each impulse.
摘要:
The invention relates to a zirconium phosphate in particles having sizes comprised within the range of from 1 to 100 .mu.m, a lamellar structure with interlayer distance, in the anhydrous state, comprised within the range of from 7.9 to 8.2 .ANG. and a surface area comprised within the range of from 9 to 20 m.sup.2 /g.The method consists in altering the lamellar structure of a zirconium phosphate with layer structure of alpha type by intercalating into it an organic substance containing a proton-acceptor group and water and by a treatment with ultrasounds, in regenerating the hydrogen form of said zirconium phosphate by an acid and in washing the same with diluted acids and/or water.
摘要:
Ion exchange inorganic films made up of alpha-type or gamma-type layered structure insoluble acid salts of tetravalent metals or their salt forms, or their intercalated forms or their organic derivatives containing polar groups. A process for the preparation of said films.
摘要:
The invention is based on the preparation of an organic solution of preferably phosphonic acids and tetravalent metals salts, preferably of Zr, Ti, Sn and Ce, in organic solvents, which behaves as a solution of layered tetravalent metals salts, preferably phosphate-phosphonates, which are completely insoluble in the known solvents. This peculiarity allows an easy insertion of particles of the above compounds in the pores of porous membranes, in the matrices of those polymers, which are soluble in the same organic solvents, as well as in the membrane/electrode interfaces of fuel cells. The use of tetravalent metals salts, preferably zirconium phosphate-phosphonates, possessing high proton conductivity (in some cases higher than 10−1 S cm−1) allows the preparation of impregnated porous membranes and of nano-polymeric membranes combining good mechanical properties, and/or reduced permeability to gaseous species, with good proton conductivity. These membranes can therefore be employed in fuel cells even at temperatures higher than 80° C. These membranes also possess a high catalytic activity and can therefore be employed in catalytic membrane reactors.
摘要:
This invention is based on the preparation of new solid acid triphosphates with compositions of the general formula M(IV)(HPO4)(H2PO4)2, where M(IV) is a tetravalent metal or a mixture of tetravalent metals. These compounds are insoluble in water the greater part of most organic solvents. They show a high non-water assisted protonic conductivity (about 0.01-0.04 S/cm at 100° C. and a relative humidity lower than 1%). These compounds can be used as proton conduction separators in electrochemical devices, to operate at low relative humidity values, as for example in different fuel cells, protonic pumps for electrochemical hydrogenation and dehydrogenation of organic compounds, or for hydrogen production from hydrogenated organic compounds by electro-reforming, or also for removing hydrogen from equilibrium reactions. These compounds can also be used in electrochemical sensors, in super capacitors and as acid catalysts in non-aqueous or anhydrous gaseous phases.
摘要:
A solid-state sensor device for determining the concentration of gases which can react with hydrogen, in particular oxygen, is disclosed, which is essentially composed of a solid-state protonic conductor put into contact, at one of its sides, with a reference electrode and, at its other side, with a composite electrode (sensor electrode), constituted by a catalytic material into contact with a hydride of a metal or of a metal alloy.
摘要:
A tetravalent metal diphosphonate-phosphite composition definable by the following general formula:M(O.sub.3 P--R--PO.sub.3).sub.1-x (HPO.sub.3).sub.2x (I)is described where:M is a tetravalent metal;x varies from 0.5 to 0.66;R is an organic radical of bivalent aromatic type, carrying side groups which increase its steric hindrance.The composition is in the form of a crystalline solid with a type .alpha. layered structure with the diphosphonic groups positioned to join said layers together by a covalent bond (pillared compounds). It has a B.E.T. surface area from 300 to 500 m.sup.2 /g depending on the nature of R in formula (I), and a porosity in the micropore radius range of less than 20 .ANG. (Angstrom), such micropores contributing to the extent of more than 95% of the total area for the most crystalline materials.
摘要:
Mixed phosphorous or arsenic salts of tetravalent metals are provided having the general formula M(HAO.sub.4).sub.2-x (HAO.sub.3).sub.x.nH.sub.2 O, where M is Zr, Ti or Hf, A is phosphorus or arsenic, x is between 0.05 and 1.95, and n is 0 to 6. The salts are highly stable and have wide potential application in the fields of ion exchange, catalysis, intercalation of molecules, solid electrolytes, and chromatography. The salts are prepared by reacting a halide, oxyhalide, nitrate, sulphate, phosphate or oxide of the tetravalent metal, preferably in an aqueous medium, with at least two oxygenated acids of phosphorus and/or arsenic.
摘要:
Inorganic layers, papers and membranes for ion exchange are made of fibrous thorium acid phosphate with a ratio PO.sub.4 /Th in the solid of about 2.