Ligated platinum group metal catalyst complex and improved process for catalytically converting alkanes to esters and derivatives thereof
OwnerRoy A. Periana, Douglas J. Taube +2inventors
InventorsRoy A. Periana, Douglas J. Taube, Scott Gamble, Henry Taube
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Abstract
This invention is an improved process for the selective oxidation of lower alkane starting materials (such as methane) into esters and, optionally, into various derivatives (such as methanol) in oxidizing acidic media using a stable platinum group metal ligand catalyst complex at elevated temperatures and to a class of novel platinum group metal ligand complexes employed bidiazine ligands, which are sufficiently stable in the oxidizing acidic media at elevated temperatures to be effective catalysts in the alkane conversion reaction.
Claims46
A process for partial oxidation of a lower alkane to form an ester which comprises contacting the lower alkane, an oxidizing agent, a strong acid and a catalyst comprising a catalytic amount of a platinum group metal stabilized with a heteroatom-containing ligand, which forms a mono-dentate or poly-dentate ligand complex with the platinum group metal, said complex being stable in the strong acid for at least about ten minutes at temperatures of about 180° C. and said contacting occurring at esterification conditions to produce a lower alkyl ester of the acid or protonated alcohol in a molar amount greater than the molar amount of catalytic metal present.
A catalyst composition comprising a catalytically active platinum group metal/ligand complex of the formula MLmXn wherein M is a platinum group metal, L is a bidiazine ligand, optionally substituted with one or more hydrocarbyl groups or substituted hydrocarbyl groups, or a substituent selected from —SO3H and fluoride or chloride or any mixture thereof, X is an oxidation resistant anion selected from halide, hydroxide, sulfate, bisulfate, nitrate and phosphate, m is 1 or 2 and n an integer of from 1 to 8.
In a process for the conversion of a lower alkane feed stream into comparatively higher molecular weight hydrocarbons, wherein the lower alkane feed stream is catalytically oxidized with an oxidizing agent in acidic media to produce an ester and the ester so obtained is then reacted with a nucleophile to yield a functionalized intermediate followed by catalytic conversion of the functionalized intermediate to a higher molecular weight hydrocarbon, the improvement which comprises employing a catalyst in the catalytic oxidation comprising a catalytic amount of a platinum group metal stabilized with a heteroatom-containing ligand which forms a mono-dentate or poly-dentate ligand complex with the platinum group metal, said complex being stable in the acidic media for at least about ten minutes at temperatures of about 180° C.
Dependencies are inferred from the claim text.