摘要:
This invention provides metal-rich siliceous compositions and methods of preparing such compositions. The compositions have comprehensibly variable and controllable metal oxide to silica ratios, surface morphology, porosity, and surface area. The method includes preparing a silicic acid, a metal oxide dispersion, and a basic heel solution. The silicic acid and metal oxide dispersion are mixed to create a blend and the blend is controllably added to the basic heel solution to form a siliceous material including colloidal silica-coated metal oxide particles. Factors such as type of silicic acid, concentration and type of metal oxide, and reaction conditions determine properties, including surface morphology and porosity, of the siliceous material
摘要:
The invention relates to crystalline boehmitic aluminas whose crystallites comprise exceptional differences of dimensions in the directions of space 020 and 120. The invention also relates to a method for producing the boehmitic aluminas and to resultant products obtained therefrom by calcination.
摘要:
The present invention relates to spheroidal alumina particles, to catalysts including such particles as a support, and to a method for manufacturing the spheroidal alumina particles that includes the following steps: a) preparing a suspension including water, an acid, and at least one boehmite powder, the ratio of the crystallite sizes of which in directions [020] and [120], obtained by X-ray diffraction using the Scherrer equation, is between 0.7 and 1; b) adding a porogenic agent, a surfactant, and optionally water, or an emulsion including at least one porogenic agent, a surfactant, and water, to the suspension of step a); c) mixing the suspension obtained in step b); d) shaping the spheroidal particles from the suspension obtained in step c) by drop coagulation; e) drying the particles obtained in step d); and f) calcining the particles obtained in step e).
摘要:
1. Process for the adjustment of the structural and/or surface properties of oxidic materials, in which the solvent is removed from solvent-containing inorganic oxide gels, at least 50% by weight of the solvent content of which consists of water, by introducing the solvent-containing inorganic oxide gel into an extraction chamber and passing therethrough an extracting agent which is gaseous under normal conditions (25 degrees C and 1 bar), with the pressure being above the critical pressure of the extracting agent.
摘要:
In einem Verfahren zur Einstellung der Struktur- und/ oder Oberflächeneigenschaften von Oxidgelen werden wasserhaltige Oxidgele mittels bezüglich Druck überkritischem Extraktionsmittel entwässert.
摘要:
Gegenstand der Erfindung sind kristalline böhmitische Tonerden, deren Kristallite ungewöhnliche Differenzen der Abmessungen in den Raumrichtungen 020 und 120 aufweisen, ein Verfahren zur ihrer Herstellung sowie aus diesen durch Calcinieren erhältliche Folgeprodukte enthaltend jeweils metallische oder nichtmetallische Oxide oder Oxidhydrate des Zirkoniums, Titans, Lanthans und/oder Bors.
摘要:
This invention provides metal-rich siliceous compositions and methods of preparing such compositions. The compositions have comprehensibly variable and controllable metal oxide to silica ratios, surface morphology, porosity, and surface area. The method includes preparing a silicic acid, a metal oxide dispersion, and a basic heel solution. The silicic acid and metal oxide dispersion are mixed to create a blend and the blend is controllably added to the basic heel solution to form a siliceous material including colloidal silica-coated metal oxide particles. Factors such as type of silicic acid, concentration and type of metal oxide, and reaction conditions determine properties, including surface morphology and porosity, of the siliceous material.
摘要:
A process for producing nano sized boehmite aluminas which are stable at alkaline pH values wherein an aqueous medium of a peptized boehmite alumina is treated with a water dispersible polycarboxylic acid polymer and optionally with an organic water dispersible base having a molecular weight ranging from 500 to 3000 and having no more than three basic groupings to produce a treated boehmite alumina which forms a stable sol at a pH of greater than 6, the treated boehmite alumina having a dispersed particle size of less than 500 nm in the sol.