摘要:
Generally, the present invention relates to improvements in metal utilization in supported, metal-containing catalysts. For example, the present invention relates to methods for directing and/or controlling metal deposition onto surfaces of porous substrates. The present invention also relates to methods for preparing catalysts in which a first metal is deposited onto a support (e.g., a porous carbon support) to provide one or more regions of a first metal at the surface of the support, and a second metal is deposited at the surface of the one or more regions of the first metal. The invention further relates to use of catalysts prepared as detailed herein in catalytic oxidation reactions, such as oxidation of a substrate selected from the group consisting of N-(phosphonomethyl)iminodiacetic acid or a salt thereof, formaldehyde, and/or formic acid.
摘要:
This invention relates to the use of a supplemental promoter in conjunction with a noble-metal-containing catalyst comprising a carbon support in catalyzing liquid phase oxidation reactions, a process for making of an improved catalyst comprising such a supplemental promoter, and an improved catalyst comprising such a supplemental promoter. In a particularly preferred embodiment, a supplemental promoter (most preferably bismuth or tellurium) is used in conjunction with a noble-metal-containing catalyst comprising a carbon support in a liquid phase oxidation process wherein N-(phosphonomethyl)iminodiacetic acid (i.e., “PMIDA”) or a salt thereof is oxidized to form N-(phosphonomethyl)glycine (i.e., “glyphosate”) or a salt thereof. The benefits of such a process include increased oxidation of the formaldehyde and formic acid by-products, and, consequently, decreased final concentrations of those by-products as well as other undesirable by-products, most notably N-methyl-N-(phosphonomethyl)glycine (i.e., “NMG”).
摘要:
This invention relates to the use of a supplemental promoter in conjunction with a noble-metal-containing catalyst comprising a carbon support in catalyzing liquid phase oxidation reactions, a process for making of an improved catalyst comprising such a supplemental promoter, and an improved catalyst comprising such a supplemental promoter. In a particularly preferred embodiment, a supplemental promoter (most preferably bismuth or tellurium) is used in conjunction with a noble-metal-containing catalyst comprising a carbon support in a liquid phase oxidation process wherein N-(phosphonomethyl)iminodiacetic acid (i.e., “PMIDA”) or a salt thereof is oxidized to form N-(phosphonomethyl)glycine (i.e., “glyphosate”) or a salt thereof. The benefits of such a process include increased oxidation of the formaldehyde and formic acid by-products, and, consequently, decreased final concentrations of those by-products as well as other undesirable by-products, most notably N-methyl-N-(phosphonomethyl)glycine (i.e., “NMG”).
摘要:
This invention relates to an improved catalyst, comprising a carbon support having a noble metal at its surface, for use in catalyzing liquid phase oxidation reactions, especially in an acidic oxidative environment and in the presence of solvents, reactants, intermediates, or products which solubilize noble metals; a process for the preparation of the improved catalyst; a liquid phase oxidation process using such a catalyst wherein the catalyst exhibits improved resistance to noble metal leaching, particularly in acidic oxidative environments and in the presence of solvents, reactants, intermediates, or products which solubilize noble metals; and a liquid phase oxidation process in which N-(phosphonomethyl)iminodiacetic acid (i.e., “PMIDA”) or a salt thereof is oxidized to form N-(phosphonomethyl)glycine (i.e., “glyphosate”) or a salt thereof using such a catalyst wherein the oxidation of the formaldehyde and formic acid by-products into carbon dioxide and water is increased.
摘要:
This invention relates to the use of a supplemental promoter in conjunction with a noble-metal-containing catalyst comprising a carbon support in catalyzing liquid phase oxidation reactions, a process for making of an improved catalyst comprising such a supplemental promoter, and an improved catalyst comprising such a supplemental promoter. In a particularly preferred embodiment, a supplemental promoter (most preferably bismuth or tellurium) is used in conjunction with a noble-metal-containing catalyst comprising a carbon support in a liquid phase oxidation process wherein N-(phosphonomethyl) iminodiacetic acid (i.e., “PMIDA”) or a salt thereof is oxidized to form N-(phosphonomethyl) glycine (i.e., “glyphosate”) or a salt thereof. The benefits of such a process include increased oxidation of the formaldehyde and formic acid by-products, and, consequently, decreased final concentrations of those by-products as well as other undesirable by-products, most notably N-methyl-N-(phosphonomethyl) glycine (i.e., “NMG”).
摘要:
This invention relates to the field of heterogeneous catalysis, and more particularly to oxidation catalysts including carbon supports having deposited thereon a noble metal and one or more optional promoters and to methods for their preparation. The invention further relates to the field of heterogeneous catalytic oxidation reactions, including the preparation of secondary amines by the catalytic oxidation of tertiary amines, such as the oxidation of an N-(phosphonomethyl)iminodiacetic acid to produce an N-(phosphonomethyl)glycine product.
摘要:
Generally, the present invention relates to improvements in metal utilization in supported, metal-containing catalysts. For example, the present invention relates to methods for directing and/or controlling metal deposition onto surfaces of porous substrates. The present invention also relates to methods for preparing catalysts in which a first metal is deposited onto a support (e.g., a porous carbon support) to provide one or more regions of a first metal at the surface of the support, and a second metal is deposited at the surface of the one or more regions of the first metal. Generally, the electropositivity of the first metal (e.g., copper or iron) is greater than the electropositivity of the second metal (e.g., a noble metal such as platinum) and the second metal is deposited at the surface of the one or more regions of the first metal by displacement of the first metal. The present invention further relates to treated substrates, catalyst precursor structures and catalysts prepared by these methods. The invention further relates to use of catalysts prepared as detailed herein in catalytic oxidation reactions, such as oxidation of a substrate selected from the group consisting of N-(phosphonomethyl)iminodiacetic acid or a salt thereof, formaldehyde, and/or formic acid.
摘要:
The present invention relates to water soluble chiral sulfonated 2,2'-bis(diphenylphosphino)-1,1'-binaphthyl and its use as organometallic catalysts for asymmetric synthesis of optically active compounds. Asymmetric reactions of the present invention include those reactions in which organometallic catalysts are commonly used. Such reactions include, but are not limited to, reduction and isomerization reactions on unsaturated substrates and carbon--carbon bond forming reactions. Examples of such reactions include, but are not limited to, hydrogenation, hydroboration, hydrosilylation, hydride reduction, hydroformylation, alkylation, allylic alkylation, arylation, alkenylation, epoxidation, hydrocyanation, disilylation, cyclization and isomerization reactions. The catalysts of the present invention provide the advantage of functioning in the presence of water without loss in enantioselectivity relative to the nonsulfonated BINAP catalyst in an organic solvent. As a result, the catalysts of the present invention may be employed in water, water miscible solvents, in aqueous--organic two phase solvent systems and in supported aqueous phase catalysts in organic solvents without loss in enantioselectivity. Further, the catalysts of the present invention may also be effectively employed in highly polar solvents such as primary alcohols and ethylene glycol. The present invention also relates to a method for conducting asymmetric reactions on prochiral unsaturated bonds contained within a compound using the water soluble chiral sulfonated 2,2'-bis(diphenylphosphino)-1,1'-binaphthyl organometallic catalysts of the present invention.
摘要:
This invention relates to an improved catalyst, comprising a carbon support having a noble metal at its surface, for use in catalyzing liquid phase oxidation reactions, especially in an acidic oxidative environment and in the presence of solvents, reactants, intermediates, or products which solubilize noble metals; a process for the preparation of the improved catalyst; a liquid phase oxidation process using such a catalyst wherein the catalyst exhibits improved resistance to noble metal leaching, particularly in acidic oxidative environments and in the presence of solvents, reactants, intermediates, or products which solubilize noble metals; and a liquid phase oxidation process in which N-(phosphonomethyl)iminodiacetic acid (i.e., “PMIDA”) or a salt thereof is oxidized to form N-(phosphonomethyl)glycine (i.e., “glyphosate”) or a salt thereof using such a catalyst wherein the oxidation of the formaldehyde and formic acid by-products into carbon dioxide and water is increased.
摘要:
This invention relates to the use of a supplemental promoter in conjunction with a noble-metal-containing catalyst comprising a carbon support in catalyzing liquid phase oxidation reactions.In a particularly preferred embodiment, a supplemental promoter (most preferably bismuth or tellurium) is used in conjunction with a noble-metal-containing catalyst comprising a carbon support in a liquid phase oxidation process wherein N-(phosphonomethyl) iminodiacetic acid (i.e., “PMIDA”) or a salt thereof is oxidized to form N-(phosphonomethyl)glycine (i.e., “glyphosate”) or a salt thereof. The benefits of such a process include oxidation of the formaldehyde and formic acid by-products, and, consequently, decreased final concentrations of those by-products as well as other undesirable by-products, most notably N-methyl-N-(phosphonomethyl)glycine (i.e., “NMG”).