Iron promotion of V‐HMS mesoporous catalysts for ultra‐deep oxidative desulfurization

Abstract

Bimetallic Fe‐V‐HMS (HMS, hexagonal mesoporous silica) catalysts with various molar ratios of iron to vanadium were synthesized using a co‐synthesis method, and investigated for oxidative desulfurization of dibenzothiophene (DBT) using tert‐butyl hydroperoxide as an oxidant. The catalysts were characterized using X‐ray diffraction, temperature‐programmed desorption of ammonia, Fourier transform infrared spectroscopy and N2 physical adsorption–desorption techniques. The Fe‐V‐HMS catalyst with a 2:1 molar ratio of iron to vanadium exhibited the highest total acidity and the highest catalytic activity. DBT was almost completely oxidized to dibenzothiophenesulfone, a species with a higher polarity that could be subsequently adsorbed on the Fe‐V‐HMS, and therefore the Fe‐V‐HMS acts as both a catalyst and an adsorbent simultaneously. The desulfurization rate was 98.1%. A pseudo‐first‐order model was fitted to the experimental data, and the activation energy was found to be 38.79 kJ mol−1. The encouraging performance of Fe‐V‐HMS offers the prospect of the design of a one‐pot oxidative desulfurization process without needing extraction of sulfones from fuel oil with a chemical solvent.

Ultradeep desulfurization of model oil through the oxidative adsorption process using Dawson‐type polyoxometalates and graphene oxide multifunctional composites

“…However, harsh reaction conditions including high temperature, high pressure, and large hydrogen consumption must be provided for hydrodesulfurization, and its removal efficiency for heteroaromatic sulfur compounds such as benzothiophene (BT), dibenzothiophene (DBT), and 4,6‐dimethyldibenzothiophene (4,6‐DMDBT) is not satisfactory due to the steric hindrance effect on the S atom. Therefore, it is imperative to explore new desulfurization methods as a complement or alternative for the conventional process, and recent studies on this topic have focused on extraction, adsorption, biodesulfurization, pervaporation, and oxidative desulfurization (ODS) . Among these methods, ODS has been critically acclaimed by various researchers, because of its mild reaction conditions and high efficiency for the removal of heteroaromatic sulfur compounds.…”