Abstract:
A process for making non-porous, dense, silica particles having a diameter of about 3 to 1000 microns, a nitrogen B.E.T. surface area less than about 1 m2/g, a total impurity content of less than about 50 ppm and a metal impurity content of less than about 15 ppm from an aqueous dispersion of fumed silica. The particles are converted into porous particles and sintered in an atmosphere having a water partial pressure of from about 0.2 to about 0.8 atmosphere for temperatures below about 1200 °C.
Abstract:
A process is described for producing a powder batch comprises a plurality of particles, wherein the particles include (a) a first catalytically active component comprising at least one transition metal or a compound thereof; (b) a second component different from said first component and capable of removing oxygen from, or releasing oxygen to, an exhaust gas stream; and (c) a third component different from said first and second components and comprising a refractory support. The process comprises providing a precursor medium comprising a liquid vehicle and a precursor to al least one of said components (a) to (c) and heating droplets of said precursor medium carried in a gas stream to remove at least part of the liquid vehicle and chemically convert said precursor to said at least one component.
Abstract:
A carbon black having a combination of properties with values in ranges selected to promote high conductivity, high hydrophobicity, and reduced outgassing in lead acid batteries while maintaining high charge acceptance and cycleability. The carbon black has a Brunauer-Emmett-Teller (BET) surface area ranging from 100 m 2 /g to 1100 m 2 /g combined with one or more properties, e.g., a surface energy (SE) of 10 mJ/m 2 or less, and/or a Raman microcrystalline planar size (L a ) of at least 22 Å, e.g., ranging from 22 Å to 50 Å. In some cases, the carbon black has a statistical thickness surface area (STSA) of at least 100 m 2 /g, e.g., ranging from 100 m 2 /g to 600 m 2 /g.
Abstract:
A catalyst composition comprises a particulate support and catalyst nanoparticles on the particulate support. The catalyst nanoparticles comprise an alloy of platinum and palladium in an atomic ratio of from about 25:75 to about 75:25 and are present in a concentration of between about 3 and about 10 wt% weight percent of the catalyst composition. The catalyst composition has an X- ray diffraction pattern that is substantially free of the (311) diffraction peak assignable to Pt x Pd 1-x , where 0.25 ≤ x ≤ 0.75.
Abstract translation:催化剂组合物包含颗粒载体和颗粒载体上的催化剂纳米颗粒。 催化剂纳米颗粒包含原子比为约25:75至约75:25的铂和钯的合金,并且以催化剂组合物的约3重量%至约10重量%的浓度存在。 催化剂组合物具有基本上不含可分配给PtxPd1-x的(311)衍射峰的X射线衍射图,其中0.25 = x = 0.75。