A study of the oxidehydration of 1,2-propanediol to propanoic acid with bifunctional catalysts

[EN] The gas-phase oxidehydration (ODH) of 1,2-propanediol to propionic acid has been studied as an intermediate step in the multi-step transformation of bio-sourced glycerol into methylmethacrylate. The reaction involves the dehydration of 1,2-propanediol into propionaldehyde, which occurs in the presence of acid active sites, and a second step of oxidation of the aldehyde to the carboxylic acid. The two reactions were carried out using a cascade strategy and multifunctional catalysts, made of W-Nb-O, W-V-O and W-Mo-V-O hexagonal tungsten bronzes, the same systems which are also active and selective in the ODH of glycerol into acrylic acid. Despite the similarities of reactions involved, the ODH of 1,2-propanediol turned out to be less selective than glycerol ODH, with best yield to propanoic acid no higher than 13%, mainly because of the parallel reaction of oxidative cleavage, occurring on the reactant itself, which led to the formation of C-1-C-2 compounds.Bandinelli, C.; Lambiase, B.; Tabanelli, T.; De Maron, J.; Dimitratos, N.; Basile, F.; Concepción Heydorn, P.... (2019). A study of the oxidehydration of 1,2-propanediol to propanoic acid with bifunctional catalysts. Applied Catalysis A General. 582:1-9. https://doi.org/10.1016/j.apcata.2019.05.0361958