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").