A Nickel/Palladium/Ruthenium-Graphene based nanocatalyst for selective catalytic hydrogenation of vegetable oils

Abstract

The catalytic hydrogenation of vegetable oils has long been the subject of study. Indeed, the reduction of un-saturations can to improve stability and increase properties suitable for a wide range of applications. Moreover, even with so much effort, the results are still far from the objectives of obtaining cis isomer of monoenes in the presence of a low amount of stearic acid. A new catalyst, obtained from a one-step synthesis, operating in mild conditions with high activity and full selectivity towards the cis configuration of 9-octadecanoic acid was proposed. A Ni/Pd/Ru active phase, with surfactant chains surfaces conjugated, results dispersed on few-layer graphene for increased efficiency exploiting the adsorbent properties of the support.The results demonstrate that the nano-hybrid made up of cheap and available Ni with very small amounts of palladium and ruthenium, allows achieving during hydrogenation of canola oil favorable cis-C18:1/C18:0 ratios, at a low catalyst loading of 1 wt.%. The addition of the Ru active phase allows successfully achieving up to 75.3 wt.% cis C18:1, and 2.46 wt.% of stearic acid, after 60 min. Additionally, it is worth noticing that only 2.6 wt.% of cis C18:1 is constituted of cis positional isomers. The graphene stabilizing nanoparticles ensures catalyst stability over cycles of use.