Oxidative desulfurization of dibenzothiophene over Fe promoted Co–Mo/Al 2 O 3 and Ni–Mo/Al 2 O 3 catalysts using hydrogen peroxide and formic acid as oxidants

Abstract

This work reports the enhancing effect of a highly cost effective and efficient metal, Fe, incorporation to Co or Ni based Mo/Al2O3 catalysts in the oxidative desulfurization (ODS) of dibenzothiophene (DBT) using H2O2 and formic acid as oxidants. The influence of operating parameters i.e. reaction time, catalyst dose, reaction temperature and oxidant amount on oxidation process was investigated. Results revealed that 99% DBT conversion was achieved at 60 °C and 150 min reaction time over Fe–Ni–Mo/Al2O3. Fe tremendously enhanced the ODS activity of Co or Ni based Mo/Al2O3 catalysts following the activity order: Fe–Ni–Mo/Al2O3 > Fe–Co–Mo/Al2O3 > Ni–Mo/Al2O3 > Co–Mo/Al2O3, while H2O2 exhibited higher oxidation activity than formic acid over all catalyst systems. Insight about the surface morphology and textural properties of fresh and spent catalysts were achieved using scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray (EDX) analysis, Atomic Absorption Spectroscopy (AAS) and BET surface area analysis, which helped in the interpretation of experimental data. The present study can be deemed as an effective approach on industrial level for ODS of fuel oils crediting to its high efficiency, low process/catalyst cost, safety and mild operating condition.