摘要:
Mixed oxide active catalysts having the formula:A.sub.a Mo.sub.c W.sub.d Co.sub.e B.sub.b O.sub.xwherein:A is at least one of the metals nickel, manganese and/or lead;B is at least one of the metals iron, bismuth, chromium and/or thallium;a is the sum of the values indicating the amounts present of each of the metals A, and is a number ranging from greater than or equal to 0 to about 4;c and d are numbers each equal to or greater than 0 and ranging to 12, with the sum c+d being about 12;e is a number ranging from about 8 to about 12;b is the sum of the values indicating the amounts present of each of the metals B, and is a number ranging from greater than 0 to about 1.5 [(c+d)-(a+e)]; andx is a number satisfying all unbalanced valences,are prepared by, in a first stage, intimately admixing in aqueous phase the salts of all metals to comprise such active catalyst, with the salts of molybdenum and/or tungsten being ammonium salts and at least one salt of at least one of the metals A and B being a nitrate; and, in a second stage, drying and calcining. In the process, the problems of ammonium nitrate formation are avoided by, in the first stage, acidifying an aqueous solution comprising the ammonium salts of molybdenum and/or tungsten to a pH ranging from about 0.5 to 3, separating the molybdic and/or tungstic acid precipitates which thereby form and preparing an aqueous suspension thereof, and then admixing therewith aqueous solutions of the metal salts of the remaining metals comprising the catalyst.
摘要:
A composite base metal oxide catalyst of improved high temperature stability is provided by prereacting a selected base metal oxide catalyst or its precursor compounds with a selected refractory high-surface-area spinel or its precursor compounds to form a crystalline solid solution of the catalyst and the spinel. This solid solution has the properties of good catalytic activity and high temperature structural and surface area stability. An example of such a composite catalyst is CuCr2O4 in solid solution with NiAl2O4.
摘要翻译:通过将所选择的基体金属氧化物催化剂或其前体化合物与选定的耐火高表面积尖晶石或其前体化合物预反应以形成催化剂的结晶固溶体和 尖晶石 该固溶体具有良好的催化活性和高温结构和表面积稳定性。 这种复合催化剂的实例是具有NiAl 2 O 4的固溶体中的CuCr 2 O 4。
摘要:
A process for the preparation of hydrogenation catalysts by contacting a carbonaceous material with a water in oil emulsion containing a salt of a hydrogenating metal, converting said salt to a hydroxide or sulfide and subsequently removing the water.
摘要:
The catalyst comprises a physical particle-form mixture of a Component A, a Component B, and a Component C, said Component A comprising at least one Group VIII noble metal, preferably platinum, deposed on a solid catalyst support material providing acidic catalytic sites, said Component B comprising a small amount of a non-noble metal of Group VIII selected from cobalt, nickel, and mixtures thereof, preferably cobalt, on a solid catalyst support material providing acidic catalytic sites, said Component C comprising a small amount of gallium deposed on a solid catalyst support material providing acidic catalytic sites, and said catalyst having been prepared by thoroughly and intimately blending finely-divided particles of said Components A, B, and C to provide a thoroughly-blended composite.The catalyst can be employed suitably in a hydrocarbon conversion process. In particular, the catalyst can be employed in a process for the reforming of a hydrocarbon stream, which process comprises contacting said stream in a reforming zone under reforming conditions and in the presence of hydrogen with said catalyst. The process can be used advantageously to reform a hydrocarbon stream that contains up to 80 ppm sulfur.
摘要:
Dehydrocyclizable hydrocarbons are converted to aromatics by contacting them at dehydrocyclization conditions with an acidic multimetallic catalytic composite comprising a combination of catalytically effective amounts of a platinum group component, a bismuth component, a cobalt component, and a halogen component with a porous carrier material. The platinum group, bismuth, cobalt and halogen components are present in the multimetallic catalyst in amounts respectively, calculated on an elemental basis, corresponding to about 0.01 to about 2 wt. % platinum group metal, about 0.05 to about 5 wt. % cobalt, about 0.01 to about 5 wt. % bismuth, and about 0.1 to about 3.5 wt. % halogen. Moreover, the catalytically active sites induced by these metallic components are uniformly dispersed throughout the porous carrier material and these metallic components are present in the catalyst in carefully controlled oxidation states such that substantially all of the platinum group component is in the elemental metallic state, substantially all of the bismuth component is preferably in an oxidation state above that of the elemental metal, and substantially all of the catalytically available cobalt component is present in the elemental metallic state or in a state which is reducible to the elemental metallic state under dehydrocyclization conditions, or in a mixture of these states. A specific example of dehydrocyclization method disclosed herein is a method for converting a feed mixture of n-hexane and n-heptane to a product mixture of benzene and toluene which involves contacting the feed mixture and a hydrogen stream with the acidic multimetallic catalyst disclosed herein at dehydrocyclization conditions.
摘要:
There are provided oxidation catalysts having a specific surface ranging m 12 to 100 m.sup.2 /g and containing as their main constituent either an oxide of cobalt or an oxide of bismuth. The catalysts further contain a promoter in the form of a rare earth oxide or thorium oxide, and they may also contain at least one oxide of manganese, iron, magnesium, chromium or niobium. Such catalytic compositions can be used for the oxidation of ammonia in a solid bed or in a fluidized bed.
摘要:
The invention relates to a novel catalyst for the selective hydrogenation of unsaturated hydrocarbons. It is characterized in that the catalyst contains a group VIII metal deposited on a support previously modified by an element chosen from within group IIIA constituted by gallium and indium.
摘要:
A catalyst composition useful for the oxidation of olefins, particularly the vapor phase oxidation of isobutylene and/or tertiary butyl alcohol to produce methacrolein, consists essentially of the combination of oxides of molybdenum, cobalt, iron, bismuth, thallium, antimony, silicon, and nickel, along with one or more members of the groups consisting of the alkali metals, the alkaline earth metals, the rare earth metals including lanthanum, tungsten, and mixtures thereof. The catalyst has a BET surface area within the range of about 0.5-10 m.sup.2 /gm and preferably within the range of about 2-6 m.sup.2 /gm. Preferably, the catalyst has no more than about 3% of the surface area associated with pores smaller than about 100 A.degree.. The catalyst is heated during its preparation to a temperature above 525.degree. C., preferably above 550.degree. C., most preferably to about 600.degree. C., for a time sufficient to achieve the desired surface area and pore size distribution and thereby to improve selectivity to methacrolein.
摘要:
New heteronuclear noble metal cluster complexes have been discovered and synthesized for the first time. These complexes are (pyridine).sub.2 Pt[Ir.sub.6 (CO).sub.15 ], (pyridine).sub.2 Pt[Ir.sub.2 (CO).sub.7 ], (pyridine).sub.3 Pt[Ru.sub.3 (CO).sub.12 ], ((C.sub.6 H.sub.5).sub.3 P).sub.2 Pt[Ir(CO).sub.3 P (C.sub.6 H.sub.5).sub.3 ].sub.2, ((C.sub.6 H.sub.5).sub.3 P).sub.2 Rh(CO)[Ir(CO).sub.4 ], and (pyridine).sub.2 Pt[Rh(CO).sub.2 (P(C.sub.6 H.sub.5).sub.3).sub.2 ].sub.2.These new heteronuclear noble metal cluster complexes are useful as supported mixed noble metal catalyst precursors. These new cluster complexes, of known stoichiometry, are deposited on anhydrous refractory inorganic oxide or carbon supports and then reduced resulting in the formation of a supported heteronuclear noble metal catalyst having the same metals stoichiometry as the starting cluster complexes. In this way, precise control can be exercised over the ratio and distribution of multiple metal components in a mixed noble metal catalyst. The usage of preformed heteronuclear noble metal cluster complexes as supported mixed metal catalyst precursors maximizes surface alloy formation and also yields unique mixed-metal cluster structures on the support surface.
摘要:
Dehydrogenatable hydrocarbons are dehydrogenated by contacting them, at dehydrogenation conditions, with a catalytic composite comprising a combination of catalytically effective amounts of a platinum or palladium component, a rhodium component and a cobalt component with a porous carrier material. A specific example of the nonacidic catalytic composite disclosed herein is a combination of a platinum or palladium component, a rhodium component, a cobalt component, and an alkali or alkaline earth component with a porous carrier material in amounts sufficient to result in a composite containing about 0.01 to about 2 wt. % platinum or palladium, about 0.01 to about 2 wt. % rhodium, about 0.05 to about 5 wt. % cobalt and about 0.1 to about 5 wt. % alkali metal or alkaline earth metal. A preferred modifying component for the disclosed catalytic composites is a Group IVA metallic component.