Iron oxide nanoparticles for rapid adsorption and enhanced catalytic oxidation of thermally cracked asphaltenes

► Fe3O4 nanoparticles were employed for adsorptive and oxidation of four different asphaltenes. ► The extent of adsorption increased with decrease in the molecular weight of the asphaltenes. ► Adsorption affinity increased as the molecular weight of asphaltenes increased. ► Fe3O4 caused a decrease in the oxidation temperature and activation energy of asphaltenes. ► Fe3O4 nanoparticles can serve as an excellent adsorbent/catalyst for heavy oil upgrading.