Bimetallic Bi–Pt, Ru–Pt and Ru–Pd and trimetallic catalysts for the selective oxidation of glyoxal into glyoxalic acid in aqueous phase

Molybdenum Oxoanions as Dispersing Agents in the Preparation of Pd/C Catalysts for the Selective Oxidation of Glyoxal

“…By contrast with previously reported results with Bi-Pd/C catalysts, where it had been identified at 24 h [45], the maximum yield in glyoxalic acid is here not yet attained after 48 h, but it is still in constant augmentation. The yield in glyoxalic acid obtained (after 48 h) is thus superior (or equal) to all former results obtained so far with the best catalysts for this reaction [28][29][30][44][45][46][47][48]. This is particularly obvious when comparing the yields in glyoxalic acid normalized with respect to the amount of active metal (Pd) [28][29][30][44][45][46][47][48], Table 2.…”

“…In consequence, we have been looking for alternative promoters for this reaction, which would not leach, but maintain the required high selectivity and activity. Ruthenium and gold were found to be promising candidates [29,30,47,48], but the former had a mitigate action that seemed to be highly dependent on the preparation procedure, while the latter did not solve the economical constraint.…”

Catalytic Oxidation Pathways for the Production of Carboxylic Acids from Biomass

“…Ruthenium is totally inactive because it is covered with hydroxyl groups that catalyze side reactions such as dismutation (Cannizzaro reaction) and direct oxidation of glyoxal into formic acid (C-C bond rupture). Various bi-and tri-metallic associations have been tested as catalysts for the selective oxidation of glyoxal into glyoxylic acid in aqueous phase [ 81 ]. All catalysts were supported on carbon and consisted of a noble metal (Pd or Pt) in association with a second (or third) metal acting as promoter (Ru or Bi).…”

The mechanism and kinetics for the selective oxidation of glyoxal to produce glyoxalic acid by Fenton’s reagent

“…Glyoxalic acid (GA) is a high value-added fine chemical, which is widely used as intermediates in food, perfume and pharmaceutical industries, particularly for the synthesis of vanillin and penicillin [1]. GA is usually produced through nitric acid oxidation of glyoxal (GO) [2], electrolytic reduction from oxalic acid (OA) [3], ozonolysis of maleic acid [4] and using the enzyme glycolate oxidase [5].…”