High surface area dual promoted iron/managanese spinel compositions
AssigneeExxon Research & Engineering Co.
InventorsRocco A. Fiato, Stuart L. Soled
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Abstract
Slurried, high surface area, Cu and Group IA or IIA dual metal promoted Mn-Fe spinels which are fully reduced and carburized provide exceptionally high catalytic activity and selectivity in the conversion ofCo/H.sub.2 to alpha-olefins, particularly when reduced and carbided in-situ. These copper and Group IA or IIA metal promoted iron-manganese catalysts maintain good activity and selectively under low pressure reaction conditions.
Claims16
A composition of matter comprising an unsupported, Group IA or IIA metal and copper promoted, single phase, iron-manganese spinel, said spinel exhibiting a powder X-ray diffraction pattern substantially isostructural with Fe.sub.3 O.sub.4, and possessing a BET surface area greater than 30 M.sup.2 /g and an iron-manganese atomic ratio greater than about 2:1.
A process for producing a composition of matter comprising an unsupported, single phase, Group IA or IIA metal and copper promoted iron-manganese spinel, said spinel exhibiting a powder X-ray diffraction pattern substantially isostructural with Fe.sub.3 O.sub.4, and possessing a BET surface area greater than 30 M.sup.2 /g and an iron-manganese atomic ratio greater than about 2:1 comprising the steps of (a) evaporating a liquid solution comprising a mixture of iron and manganese salts of at least one alpha-hydroxy aliphatic carboxylic acid, wherein the molar ratio of total moles of said acid to total moles of said iron and manganese, taken as free metals, is about 1:1, or above, and wherein the atomic ratio of iron:manganese, taken as the free metals in said mixture, is greater than 2 to 1, yielding an amorphous residue;
- (b) calcining said residue at elevated temperature for a time sufficient to yield an iron-manganese spinel, exhibiting only one spinel phase, isostructural with Fe.sub.3 O.sub.4, as determined by powder X-ray diffractometry;
- (c) impregnating the composition of (b) with a solution of a copper salt and a salt of a Group IA or IIA metal;
- and (d) drying the resulting impregnate.
A composition of matter comprising, a single phase, copper and Group IA or IIA metal promoted iron-manganese spinel produced by a process comprising the steps of (a) evaporating a liquid solution comprising a mixture of iron and manganese salts of at least one alpha-hydroxy aliphatic carboxylic acid, wherein the molar ratio of total moles of said acid to total moles of said iron and manganese, taken as free metals, is about 1:1, or above, and wherein the atomic ratio of iron:manganese, taken as the free metals in said mixture, is greater than 2 to 1, yielding an amorphous residue;
- (b) calcining said residue at elevated temperature for a time sufficient to yield a spinel;
- (c) impregnating the composition of (b) with a solution of a copper salt and a salt of a Group IA or IIA metal;
- and (d) drying the resulting impregnate.
Dependencies are inferred from the claim text.