摘要:
Nanoporous and mesoporous carbon materials are fabricated in a pyrolysis process in which a starting mixture including a carbonizing polymer and a pyrolyzing polymer are employed. In one instance, the carbonizing polymer and pyrolyzing polymer are joined together in the form of a block copolymer. In another instance, the carbonizing polymer is a polyfurfuryl alcohol and the pyrolyzing polymer is polyethylene glycol diacid. These two polymer materials are mixed together and not copolymerized. The pore structure of the material may be controlled by controlling the molecular weight of various of the polymer components.
摘要:
A gas permeable, carbon based, nanocomposite membrane comprises a nanoporous carbon matrix comprising a pyrolyzed polymer, and a plurality of nanoparticles of carbon or an inorganic compound disposed in the matrix. The matrix is prepared by pyrolyzing a polymer, and nanoparticles of the particulate material are disposed in the polymer prior to pyrolysis. The particles may be disposed in a precursor of the polymer, which precursor is subsequently polymerized, or in the polymer itself.
摘要:
The present invention relates to an improved catalyst for the selective synthesis of monomethylamine (MMA) and dimethylamine (DMA) at the expense of trimethylamine (TMA) for a starting feed of methanol and/or dimethyl ether and ammonia. The current industrial catalyst for this process is a standard SiO.sub.2 /Al.sub.2 O.sub.3 material. The present invention combines this standard catalyst with microporous carbon molecular sieves (CMS) to form a composite material (i.e., a CMS/SiO.sub.2 /Al.sub.2 O.sub.3 material) with higher selectivity for the desired products MMA and DMA. The invention also relates to methods of making the improved catalyst and a process of using the improved catalyst material in the production of MMA and DMA.
摘要翻译:本发明涉及用于甲醇和/或二甲醚和氨的起始原料以三甲胺(TMA)为代价选择性合成一甲胺(MMA)和二甲胺(DMA)的改进的催化剂。 目前用于该工艺的工业催化剂是标准的SiO 2 / Al 2 O 3材料。 本发明将该标准催化剂与微孔碳分子筛(CMS)组合以形成对所需产物MMA和DMA具有较高选择性的复合材料(即,CMS / SiO 2 / Al 2 O 3材料)。 本发明还涉及制备改进的催化剂的方法以及在制备MMA和DMA中使用改进的催化剂材料的方法。
摘要:
This invention relates to catalyst supports, methods for making them, and to catalysts prepared therefrom. More particularly, it relates to binary oxidic catalyst support materials comprising titania and zirconia with high porosity and high surface area prepared by either a pH swing technique or a constant pH technique followed by calcination at a temperature below 450.degree. C., with such materials being impregnated with catalytically active metal components.
摘要:
New catalysts comprising molybdenum on supports of defined wide-pore carbons are useful as catalyst for reaction of CO with H.sub.2 for synthesis of hydrocarbons. Catalysts may be made by depositing Mo(CO).sub.6 on the carbon support particles by vapor deposition or solution impregnation. The catalyst may also comprise a second metal, such as rhodium or palladium.
摘要:
A novel supported mesoporous carbon ultrafiltration membrane and process for producing the same. The membranes comprise a mesoporous carbon layer that exists both within and external to the porous support. A liquid polymer precursor composition comprising both carbonizing and noncarbonizing templating polymers is deposited on the porous metal support. The coated support is then heated in an inert-gas atmosphere to pyrolyze the polymeric precursor and form a mesoporous carbon layer on and within the support. The pore-size of the membranes is dependent on the molecular weight of the noncarbonizing templating polymer precursor. The mesoporous carbon layer is stable and can withstand high temperatures and exposure to organic chemicals. Additionally, the porous metal support provides excellent strength properties. The composite structure of the membrane provides novel structural properties and allows for increased operating pressures allowing for greater membrane flow rates. The invention also relates to the use of the novel ultrafiltration membrane to separate macromolecules from solution. An example is shown separating bovine serum albumin from water. The membrane functions by separating and by selective adsorption. Because of the membrane's porous metal support, it is well suited to industrial applications. The unique properties of the supported mesoporous carbon membrane also allow the membrane to be used in transient pressure or temperature swing separations processes. Such processes were not previously possible with existing mesoporous membranes. The present invention, however, possesses the requisite physical properties to perform such novel ultrafiltration processes.
摘要:
Carbogenic molecular sieve devices comprising a porous support (e.g., a metal support) having a carbogenic molecular sieve membrane attached to one or more surfaces of the support so that small pores in the membrane are in communication with larger pores in the support and methods of making the devices.
摘要:
A method for the preparation of a carbon molecular sieve capable of separating acid gases and fluorocarbons of the formula C.sub.a H.sub.b X.sub.c F.sub.d, wherein a is from 1 to about 6, b is from 0 to about 13, c is from 0 to about 13, d is from 1 to about 14, and X is a halogen; on the basis of shape selectivity and size exclusion. A precursor resin is heated at about 0.2.degree. C. per minute to about 500.degree. C. Then the resin is soaked at about 500.degree. C. for about 6 hours in flowing inert gas.
摘要:
Catalytic membranes comprising highly-dispersed, catalytically-active metals in nanoporous carbon membranes and a novel single-phase process to produce the membranes.
摘要:
A beam or flow of a reactive or metastable precursor such as a hydride or organometallic compound is created, and this beam or flow is used to treat (e.g. dope or coat or otherwise modify) a substrate, e.g. an advanced material such as a semiconductor layer, a photovoltaic cell, or a solar cell. The beam or flow can also be directed into a storage zone so that the precursor or precursors can be collected for future use. The beam or flow is created in an apparatus comprising at least three zones. Zone 1 is irradiated with microwave energy to generate a reactive gas rich in free radicals (e.g. rich in H.sup.., CH.sub.3.sup.., etc.) zone 2 (downstream from zone 1) is substantially free of microwave energy and contains a target which is impinged upon by the free radicals and becomes a source of the precursor; zone 3 (downstream from zone 2) is where the precursors are either collected for storage or are used to treat the substrate. In a typical apparatus of this invention, a feed gas such as H.sub.2 or CH.sub.4 is introduced into an elongated tube 50 which communicates with a microwave cavity 57 containing a microwave plasma. A reactive gas containing free radicals (and perhaps some ions) flows from cavity (57 to target 61, where the free radicals react with the target to form the precursor (e.g. a hydride such as silane). When the precursor enters zone 3 it can treat an advanced material 73, e.g. by decomposing into Si+2H.sub.2. The Si is deposited on substrate 73 and the liberated H.sub.2 is pumped away. The pumping system also keeps the interior of the apparatus under subatmospheric pressure, e.g. 0.1 to 10 torr.