Oxidative Desulfurization of Gas Oil Catalyzed by (TBA)₄PW₁₁Fe@PbO as an Efficient and Recoverable Heterogeneous Phase-Transfer Nanocatalyst

Abstract

In this paper, a tetra(n-butyl)ammonium salt of iron III -substituted phosphotungstate@lead oxide composite, (TBA) 4 PW 11 Fe@PbO, was successfully synthesized by the thermal decomposition method as a nanocatalyst for oxidative desulfurization (ODS) of gas oil. The incorporation of the materials was confirmed by Fourier transform infrared spectroscopy (FTIR), ultraviolet−visible (UV−vis), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and 31 P nuclear magnetic resonance (NMR) characterization methods. To evaluate the catalytic activity of (TBA) 4 PW 11 Fe@PbO, the ODS process was carried out using a CH 3 COOH/H 2 O 2 oxidizing agent at 60 °C. From the attained results, the total sulfur and mercaptan content of real gas oil were reduced with 97% efficiency after 2 h. Furthermore, the various comparative experiments were performed to investigate the capability of (TBA) 4 PW 11 Fe@PbO in ODS of prepared model fuel. Results were indicated that the kinetics of sulfur oxidation fitted the pseudo-first-order kinetic model. The probable mechanism was proposed via the electrophilic mechanism through the formation of a peroxometalate intermediate complex with phasetransfer properties. After 5 oxidation runs, the heterogeneous nanocatalyst was separated and recovered easily.

Synthesis and Characterization of New Inorganic‐Organic Hybrid Nanocomposite PMo11Cu@MgCu2O4@CS as an Efficient Heterogeneous Nanocatalyst for ODS of Real Fuel

“…The results of XRD for (a) PMo 11 Cu, (b) CS, (c) MgCu 2 O 4 , and (d) PMo 11 Cu@MgCu 2 O 4 @CS are presented in Figure . XRD patterns in Figure (a) exhibit the characteristic diffraction peaks of PMo 11 Cu at 2θ values of 19.19°, 23.10°, 24.40°, 26.58°, 27.60° and 29.62° . The crystalline nature of pure Chitosan that is shown in Figure (b), has a strong peak in 19.83° which exhibits its crystalline nature .…”

“…Hydrogen peroxide reacts with ethanoic acid (CH 3 COOH) to make peracid (CH 3 COOOH) as an oxygen active source (step 1). The terminal Mo or Cu (Mo=O d or Cu=O d ) in PMo 11 Cu structure accept active oxygen from generated peracid to produce peroxo‐metal intermediate (step 2) . In this system the H 2 O molecules are produced as a by‐product.…”

“…Where, A is the Arrhenius frequency factor, E a the apparent activation energy, R universal gas constant and T the reaction temperature (in Kelvin), respectively . The E a value were estimated by graphing ln k versus 1/T (Figure ).…”

Facile synthesis of inorganic–organic Fe2W18Fe4@NiO@CTS hybrid nanocatalyst induced efficient performance in oxidative desulfurization of real fuel

“…Therefore, researchers have begun to focus on the development of integrated approaches for the deep desulfurization. The application of ODS in liquid fuels has been attracted more interest in recent decades . It can be carried out under mild environmental conditions (low temperature and pressure) and economically viable.…”

Synthesis of Organic−Inorganic Hybrid Nanocomposite Polyoxometalate/Metal Oxide/CS Polymer (PMnW11@TiO2@CS): Nanocatalyst for Oxidative Desulfurization of Real Fuel

“…The sharp peaks around (2θ=25.91, 37.86, and 48.13°) of the anatase phase are clearly observed in the Figure (b) . The XRD pattern of pure CS that is shown in Figure (c), have a sharp peak in 19–21° which indicates the semi crystalline nature of this polymer . As shown in (Figure d), the PMnW 11 @TiO 2 @CS displayed same diffraction peaks, exhibit that the synthesized catalyst was the TiO 2 composites consisting of anatase particles.…”