DEEPLY REDUCED OXIDATION CATALYST AND ITS USE FOR CATALYZING LIQUID PHASE OXIDATION REACTIONS

摘要

The present invention relates to a process for the preparation of N-(phosphonomethyl)glycine or a salt thereof, the process comprising contacting N--(phosphonomethyl)iminodiacetic acid or a salt thereof with an oxidation catalyst in a solution or slurry having a pH less than 7 and in the presence of oxygen, wherein the catalyst comprises a carbon support having a noble metal and at least one promoter at a surface of the carbon support, the noble metal is selected from the group consisting of platinum, palladium, ruthenium, rhodium, iridium, silver, osmium, gold and combinations thereof, and the promoter is selected from the group consisting of tin, bismuth, lead, cadmium, magnesium, manganese, nickel, aluminum, cobalt, titanium, antimony, selenium, iron, rhenium, cerium, zinc, and zirconium. The present invention also relates to a process for the preparation of a product comprising N--(phosphonomethyl)glycine or a salt thereof by oxidizing a reagent comprising N-(phosphonomethyl)iminodiacetic acid or a salt thereof.