Extractive-catalytic oxidative desulfurization of a model fuel over vanadium-containing heteropolyacids immobilized on amine-functionalized magnetic graphene oxide: a comparative study between Keggin and Dawson-type heteropolyacids and process optimization via response surface methodology

Abstract

Keggin and Dawson-type vanadium-containing heteropolyacids (HPAs) were synthesized and then covalently immobilized on amine-functionalized magnetic graphene oxide (APTES-MGO). Several techniques, including XRD, SEM-EDX, FT-IR, VSM, TGA, ICP-OES, N2 adsorption-desorption isotherms,...

Efficient catalytic oxidative desulfurization of liquid fuels over tungsten oxide supported on metakaolin surface

“…Also, at short oxidation time the conversion was low due to the contact time of the reagents was not enough. It should be mentioned that a longer process time decreased the DBT removal rate [45,48] …”

“…However, an excess amount of the H 2 O 2 caused to conduct the side reaction and produce undesirable substances and this hindered the oxidation of the DBT compound. Performing the ODS process at a higher temperature can easily decompose the oxidant and make water and O 2 molecules, which decreases the efficiency [42,48] …”

“…Performing the ODS process at a higher temperature can easily decompose the oxidant and make water and O 2 molecules, which decreases the efficiency. [42,48] Figure 8c demonstrates the interaction impact of the reaction temperature and time on DBT removal at the center value of the other parameters. The results show that raising the temperature and reaction time up to certain values increase the sulfur removal rate.…”

“…It should be mentioned that a longer process time decreased the DBT removal rate. [45,48] The binary effect of the temperature and O/S molar ratio on the efficiency is depicted in Figure 8b. Clearly, increasing the O/ S molar ratio in a range of 10-12 resulted in augmenting the DBT conversion.…”

Using Keggin-Type Polyoxometalates of PWFe@Fe2O3@Carbon Fiber and PWFe@Fe2O3@Pumice Stone for Catalytic Oxidative Desulfurization of Liquid Model Fuel

“…The desulfurization efficiency of 93 and 84% was acquired with Keggin and Dawson POTs-based catalysts, respectively. Mohammadi-Nejati and Shahhosseini applied Keggin- and Dawson-type heteropolyacids supported on amine-functionalized magnetic graphene oxide for the ODS of model oil. Their results displayed that the Keggin-type was more active than the Dawson-type heteropolyacids.…”