| 摘要 |
#CMT# #/CMT# Strip-like or sheet-like valve metal and valve metal suboxide structures have a transverse dimension of 5-100 nm. #CMT# : #/CMT# An independent claim is included for a process of reducing valve metal oxides using the vapor of reducing metals at reduction temperature to form lamellar nanosize structures, where the reduced valve metal oxide is frozen before thermal decomposition of lamellar structure and transformation into coarsened structures. #CMT#USE : #/CMT# Strip-like or sheet-like valve metal and valve metal suboxide structures in the form of surface strip structures, foils, or wires (claimed), useful as catalysts, support materials for catalysts, in the field of membrane and filter technology, in medical sector as implant material, as storage materials in secondary batteries, and as anode material of capacitors. #CMT#ADVANTAGE : #/CMT# After the oxides of the reducing metals have been leached out, the now free-standing lamellar structures of the valve metals remain geometrically stable since they are well sintered to the adjacent, differently oriented lamellar structures via the end parts of the individual layers. The original (polycrystalline) valve metal oxide particle is converted into an aggregated valve metal particle whose primary particles comprise layer structure groups of differing orientation and which are sintered to one another. Thus, a stable interpenetrating structure of metal and flat pores is formed. #CMT#INORGANIC CHEMISTRY : #/CMT# Preferred Component: The valve metal suboxide structure has a formula of NbO x. x : greater than 0.7, but less than 1.3. Preferred Process: Oxides of Al, Hf, Ti, Zr, V, Mo, W, preferably Nb, and/or Ta and their mixed oxides are used as oxides to be reduced. #CMT#METALLURGY : #/CMT# Preferred Component: The valve metal and valve metal suboxide structures have a sheet- or layer-like primary structure in the form of powders. The strips or lamellae are aligned parallel in groups. The valve metal structures comprise titanium (Ti), zirconium (Zr), vanadium (V), molybdenum (Mo), tungsten (W), hafnium (Hf), aluminum (Al), or preferably niobium (Nb), tantalum (Ta), or their alloys. The valve metal and valve metal suboxide structures comprise reducing metal(s) (10-500 ppm). Preferred Parameter: The valve metal structures in the form of foils or wires have strips, which have width of 5-100 nm and a strip spacing of 1-2 times the strip width. The transverse dimension or strip width is 8-50 nm. Preferred Process: Reduction is carried out at an inert gas pressure of less than 0.2 bar and vapor pressure of the reducing metal of 10 -> 2>-0.4 bar. The reduction product is cooled below 100[deg] C, within minutes immediately after the reduction is complete. Lithium, aluminum, calcium, and/or preferably magnesium are used as reducing metal. |
