Palm Oil Valorization through the Oxidative Cleavage of Unsaturated Fatty Acids with Ru-Carbon Catalysts

Abstract

Palm oil valorization for the production of azelaic acid, highly demanded for the treatment of skin cancer, was performed through the oxidative cleavage of unsaturated fatty acids. In this reaction, olefinic bonds are broken to yield carboxylic and dicarboxylic acids. To do so, carbon black and carbon micrometric particles were functionalized with polydopamine to form complexes with Ru. These Ru-carbon catalysts were fully characterized before catalytic tests, where triglycerides within palm oil were transformed into fatty acid methyl esters first and then incorporated in our catalytic system formed by H2O/MeCN/AcOEt. After adding NaIO4 and N-methylmorpholine N-oxide (oxidizing agents), our Ru-carbon catalysts reached a complete >99% conversion in 5 h of reaction at room temperature with yields of azelaic acid around 85%. Although Ru species were found in the liquid phase during the reaction, the solid catalysts managed to recover them to keep the same catalytic activity for five recycling tests. Therefore, our Ru-carbon catalysts open a novel route for the production of a high-value-added product with medicinal applications from a cheap feedstock such as palm oil.