چكيده به لاتين
In the contemporary time, there has been a notable rise in the focus on implementing eco-friendly processes, particularly in utilizing solid catalysts within the realms of research and industry. This surge in attention has prompted extensive research endeavors within academic circles, eventually leading to practical applications in industrial settings. Within the scope of this particular study, a new nanocomposite was synthesized for the purpose of producing fuel with reduced sulfur content (S ≤10 ppm), involving the encapsulation of sandwich-type polyoxometalate clusters (Fe2W18Fe4) on the surface of MOF-Ni-100 for the first time. Various techniques, such as FT-IR, UV-vis, XRD, SEM, EDX, and BET were employed to characterize the properties of the synthesized material. The Fe2W18Fe4@MOF-Ni-100 nanocomposite exhibited promising potential as a catalyst for oxidative desulfurization (ODS) of both real and model gasoline. The catalytic efficiency of this nanocatalyst was evaluated using a hydrogen peroxide/acetic acid (H2O2/CH3COOH) oxidizing system at a volume ratio of 2:1. The results of the ODS tests indicated that 0.1 g of Fe2W18Fe4@MOF-Ni-100 at 35 °C for 60 min achieved a substantial desulfurization efficiency (≥98%) under optimized operating conditions. Furthermore, a notable reduction in total sulfur concentration was observed in real gasoline, decreasing from 0.4995 to 0.0115 wt%. Additionally, the Fe2W18Fe4@MOF-Ni-100 nanocomposite was assessed as a heterogeneous catalyst for the water oxidation process in the oxygen evolution reaction (OER) under neutral pH conditions (N2-saturated from 0.1 M Na2SO4). The electrochemical characteristics of the nanocomposite were studied through cyclic voltammetry (CV), linear sweep voltammetry (LSV), and electrochemical impedance spectroscopy (EIS). The nanocatalyst demonstrated a low onset potential of 1.1 V vs. NHE, an overpotential of 269 mV at a current density of 10 mA.cm-2, and a Tafel slope of 73 mV.dec-1. Moreover, a key objective of the project is the advancement of electrode materials with high capacity to facilitate hydrogen storage and address the escalating challenges stemming from the energy crisis. To this end, a new nanocomposite was synthesized by immobilizing the potassium salt of Keggin-type polyoxometalate substituted with Zn (H6[ZnW12O40]) on the surface of NiZn2O4 ceramic. The synthesized nanocomposite (ZnW12O40/NiZn2O4) was characterized using FT-IR, UV-vis, XRD, SEM, EDX, BET, and TGA-DTG techniques. Furthermore, the electrochemical properties of the materials were explored through CV and charge-discharge chronopotentiometry (CHP) analyses. The initial cycle of hydrogen storage by the nanocomposite in a 6M KOH medium, at a current density of 2 mA, yielded a hydrogen discharge capacity of 340 mAh/g, which progressively increased to 900 mAh/g after 20 storage cycles
