Modulated Synthesis of a Novel Nickel-Based Metal–Organic Framework Composite Material for the Adsorptive Desulfurization of Liquid Fuels

Abstract

Removing sulfur from liquid fuels has become an important issue in a global society. Modulated synthesis is known to improve the crystallinity of materials, ease of handling, control of crystallite size, and degree of aggregation. A group of adsorbents [activated carbon (AC), a novel synthesized Ni-based metal–organic framework (Ni-BDC), and composites of AC@Ni-BDC treated with different concentrations of nitric acid and modulator (formic acid)] were characterized using X-ray diffractometer (XRD), high-resolution transmission electron microscopy (HR-TEM), Fourier transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET), and temperature-programmed desorption (TPD)-pyridine studies. The adsorbents were also evaluated for adsorptive desulfurization. The quantities of both AC and the modulator were observed to influence the nucleation of Ni-BDC, crystallite size, and crystallinity. The adsorption activity of the composite toward thiophene (TH) was the average of the two materials (i.e., AC and Ni-BDC), while the activity doubled toward dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT) with respect to the excepted average. The improved activity was attributed to enhanced pore structure, crystallinity, and synergistic effects that produced stronger acidic sites.

Developing New MOF-Based Hybrid Materials for Efficient Adsorptive Desulfurization of a Refractory Sulfur Compound

“…43 As shown in Figure 2, the PXRD pattern of pure activated carbon with weak and wide diffraction peaks shows a typical amorphous structure. 45,46 From the previous studies, 39 it is reported that nitric acid treatment of activated carbon has no effect on the phases present. After incorporating HNO 3 -treated activated carbon, the peak positions of the AC@MIL-53(Cr) composites did not show a difference from those found in the XRD pattern of parent MIL-53(Cr).…”

“…35 According to reports, the development of a suitable pore structure for the selective adsorption of a specific adsorbate, 33,36 an increase in the volume of the composites, 37 and synergistic effects on the surface sites of metal ions 38 are typically responsible for an increase in activity when composite materials are used in adsorption. 39 It has been reported that activated carbon has high selectivity for the adsorption of sulfur compounds with high molecular weight, 40 while the removal of low-molecular-weight sulfur compounds is where MOFs usually excel. 39 Synthesizing AC and metal organic framework composites for adsorptive desulfurization would therefore be intriguing.…”

“…39 It has been reported that activated carbon has high selectivity for the adsorption of sulfur compounds with high molecular weight, 40 while the removal of low-molecular-weight sulfur compounds is where MOFs usually excel. 39 Synthesizing AC and metal organic framework composites for adsorptive desulfurization would therefore be intriguing.…”

Constructing Dual-Function TiO2/MWCNTs-NH2-HPW Composites as Both Catalysts and Adsorbents for Highly Efficient Oxidative Adsorption Desulfurization in Fuel Oil

“…Vehicle exhaust contains harmful SO x and its derivatives, which can cause rain acidification, haze, and atmospheric particulate matter pollution, thereby causing harm to the environment and human beings. − Therefore, researchers are giving increasing attention to environmental problems. The key problem of the removal of S-containing compounds such as mercaptan, sulfide, disulfide, and thiophene from fuel oil urgently needs to be solved. − To date, many desulfurization processes have been developed, such as hydrodesulfurization (HDS), − oxidative desulfurization (ODS), ,− oxidative–extraction desulfurization (OED), adsorption desulfurization, , ionic liquid extraction desulfurization, and biological desulfurization . Among them, ODS is considered a promising deep desulfurization method due to its mild operating conditions, energy conservation, and high efficiency of removing refractory aromatic sulfides. , …”

“…The key problem of the removal of S-containing compounds such as mercaptan, sulfide, disulfide, and thiophene from fuel oil urgently needs to be solved. 4−6 To date, many desulfurization processes have been developed, such as hydrodesulfurization (HDS), 7−9 oxidative desulfurization (ODS), 1,10−12 oxidative−extraction desulfurization (OED), 13 adsorption desulfurization, 14,15 ionic liquid extraction desulfurization, 16 and biological desulfurization. 17 Among them, ODS is considered a promising deep desulfurization method due to its mild operating conditions, energy conservation, and high efficiency of removing refractory aromatic sulfides.…”