摘要:
Compositions having a host phase of a niobate or tantalate of a divalent or trivalent metal and containing vanadium from one atom present to the limit of solid solubility in the host phase. Host phases of the rutile, columbite and trirutile structure are disclosed. The compositions are useful in the partial oxidation and ammoxidation of lower alkanes.
摘要:
Mixed oxides of bismuth with other metals of the perovskite structure and having vacant lattice sites in the same lattice positions occupied by bismuth are disclosed as partial oxidation and ammoxidation catalysts. Such oxides are used as catalysts in the improved method of oxidizing an acyclic hydrocarbon of 1-10 carbons having at most one olefinic unsaturation by reacting the acyclic hydrocarbon in the vapor phase with oxygen in the presence of the solid catalyst to form products having carbon, hydrogen and oxygen.
摘要:
Catalyst of cuprous chloride, as a first layer, on a carrier of particles of pyrogenic anhydrous silica or titania, or alpha-alumina produced from pyrogenic gamma-alumina, having as a second layer an alkali metal chloride especially KCl, and preferably also a rare earth metal chloride; especially LaCl.sub.3 ; formed by impregnation using non-aqueous solvents, especially CuCl in acetonitrile followed by KCl/LaCl.sub.3 in formic acid. The catalyst is effective at desirable reaction rates at temperatures well below 400.degree. C., such as 200.degree.-300.degree. C. and even below 200.degree. C., under certain conditions, for oxyhydrochlorination of organic materials such as methane; and is also effective for production of chlorine by the Deacon process at relatively low temperatures. Problems due to catalyst volatility and melting are substantially mitigated.
摘要:
This invention provides an apparatus and method whereby variable amounts of adsorbent are dosed over a porous sample to measure the equilibrium amount adsorbed by a sample over more than two orders of magnitude in pressure. The apparatus fills a fixed volume to variable pressures of adsorbent and/or provides multiple doses of adsorbent from a fixed volume in order to change the amount of gas to which the sample is exposed. Thus, a sample is exposed to doses of adsorbent that span over an order of magnitude in amount.The improved apparatus employs substantially larger capacity tubing and valves (diameters greater than 0.25 inch ID) than those that have been employed in prior apparatuses for the measurement of adsorption by porous solids. Further, the improved apparatus employs a vacuum system capable of substantially lower pressures than those conventionally employed for the measurement of adsorption by porous solids. These innovations allow for a sample to be evacuated efficiently to lower pressures than in prior apparatuses employed for the measurement of equilibrium adsorption by porous solids.The amount adsorbed is measured after sufficient time is allowed for equilibrium to be achieved (as determined by the changes in adsorbent pressure with time). This time between equilibrium measurements varies throughout a series of measurements.The disclosed adsorption apparatus and method allow for variations in the amount of adsorbent exposed to the sample for variable periods of time. This enables more efficient measurement of adsorption on porous solids over more than two orders of magnitude in pressure.