Luisa Martins

Abstract:

Adipic acid, nylon precursor, is a relevant commodity produced worldwide: over 3.5 millions of metric tons/year, growing ca. 5%/year. Currently, the industrial production of adipic acid uses a two-step process: a) oxidation of cyclohexane to KA oil (cyclohexanol and cyclohexanone mixture), followed by the b) oxidation of KA oil with an excess of concentrated nitric acid. Among other disadvantages, the nitrous oxide emission from this process (300 kg of N2O per ton of adipic acid, measurably contributes to global warming and ozone depletion. Therefore, the development of a more efficient adipic acid production process that is less damaging to the environment is an important subject in chemical research. This lecture will address the recent achievements towards the development of a sustainable chemical process for adipic acid production. In particular, the direct (single-pot) cyclohexane oxidation to adipic acid in a solvent-, heating-, radiation- and N2O-free new catalytic protocol, which could provide an ideal solution to this serious problem, is presented and discussed.