Selective oxidation of cyclohexane to k-a oil using heterogeneous catalysts

Abstract

This doctoral thesis framed the co-supervision agreement (co-tutela) between the Universities of Milan and Cádiz. My thesis project was aimed at the development of innovative heterogeneous catalysts for the selective oxidation of cyclohexane to KA oil. Among the materials employed, supported and unsupported catalytic systems containing Fe, Co, Au, Cu, Ce and/or Zr were prepared and tested. The prepared materials were tuned through preparation and characterization and selected in terms of selectivity to the desired product, but also productivity of KA oil compared to state-of-the-art competitors. Numerous catalytic tests were performed and were necessary to study the optimal reaction conditions, as the right catalyst:substrate ratio, the influence of the initial concentration of the radical initiator, the stirring and the sampling methodologies. Moreover, the difficulties existing in products analysis were addressed by the utilization of different techniques (GC, GC-MS, HPLC). All the new catalysts were tuned and tested to work under much milder reaction conditions (120°C and 4 bar pressure) than the industrial practice and most state-of-the-art works, using O2 as oxidant. In Milan, due to the available equipment and thanks to the experience of the group in catalysts preparation, my focus was oriented to the preparation of new materials, catalytic testing, and thorough products analysis. On the other hand, thanks to the advanced characterization techniques present in Cádiz and following the purpose of my co-tutela there, during my stay I have been trained on electron microscopy and other solid-state analytical techniques (XRD, XPS, BET) which I successfully utilized for characterizing the catalysts, with the aim of inferring important structure-activity correlation