New Conduct in the Adsorptive Removal of Sulfur Compounds by New Nickel–Molybdenum Adsorbent

Abstract

The article states the first preparation of NiMo layered double hydroxide (LDH) adsorbent for the removal of dibenzothiophene (DBT) form n-heptane solution and desulfurization of gas oil. The existence of (Mo6+) in Ni2+Mo6+ LDH was proven by X-ray photoelectron spectroscopy (XPS), while X-ray diffraction and X-ray fluorescence patterns, Fourier transform infrared spectra, scanning electron microscopy images, and differential scanning calorimetry–thermogravimetric analysis and Brunauer–Emmett–Teller analysis were applied for the composition and surface characterizations. Experimentally, NiMo LDH exhibited a different conduct in the adsorption elimination of sulfur in the existence of aromatics; the sulfur uptake was increased with the increase of the aromatic content in accordance with its own highly charged surface as a result of the formation of +4 balancing charges between Ni2+and Mo6+ through the brucite layers. The material achieved adsorption capacity of 48.8 mg g–1 sulfur for DBT at 25 °C follows a pseudo-second-order kinetic type and Langmuir isotherm. NiMo LDH adsorbent showed a remarked desulfurization of gas oil by 79.6%, although it has a high aromatic content (33%). A π-complexation between the Ssulfur atoms and Mo6+ was proposed through surface adsorption. The material conserved its parental structure and adsorptive activity after being regenerated seven times.