Amino-Modified Fe-Terephthalate Metal–Organic Framework as an Efficient Catalyst for the Selective Oxidation of H₂S

Abstract

Classical amino-functionalized Fe-terephthalate metal-organic framework NH-MIL-53(Fe) and its parent framework MIL-53(Fe) were prepared via simple hydrothermal methods. The catalytic performaces of these two Fe-MOFs were explored for the selective oxidation of HS. The physicochemical properties of the fresh and used Fe-MOFs catalysts were investigated by XRD, BET, SEM, FT-IR, CO-TPD, and XPS techniques. It was found that the introduction of amino groups reduces the activation energies for HS oxidation and endows this catalyst surface with moderate basic sites. As a result, the NH-MIL-53(Fe) catalyst displays high HS conversion and near 100% S selectivity in the temperature range of 130-160 °C, outperforming commercial FeO and activated carbon. Moreover, a plausible reaction route for HS selective oxidation over NH-MIL-53(Fe) is proposed. This work opens up the possibility of utilizing MOFs as efficient catalyst for desulfuration reactions.

Morphology evolution of acetic acid-modulated MIL-53(Fe) for efficient selective oxidation of H2S

“…All of the samples exhibit the characteristic stretching vibrations of carboxylate groups in the range of 1700−1400 cm −1 . The peak at 746 cm −1 is ascribed to the C-H bending vibration of aromatic ring [35,36]. As for the peak at 545 cm −1 , it is related to Fe-O vibration [37].…”

Hydrogen Sulfide (H2S) Removal via MOFs

“…It was also noted that the adsorption isotherms of all gases in halogenated and initial MOFs are of typical type I, suggesting a rigid structure. Functionalization with halogens could improve the adsorption of H 2 S in unit volume of sorbents, notably in low-pressure range, following an order MIL-47( More recently, Zheng et al [68] probed the selective oxidation of H 2 S using the classical amino-modified NH 2 -MIL-53(Fe) and its parent analogue MIL-53(Fe), prepared by means of a simple hydrothermal method. Various characterization methods were carried out, such as x-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), CO 2 temperature-programmed desorption (CO 2 -TPD), and x-ray photoelectron spectroscopy (XPS), to provide an exegesis regarding the physicochemical properties of the solids.…”

“…More recently, Zheng et al [ 68 ] probed the selective oxidation of H 2 S using the classical amino-modified NH 2 -MIL-53(Fe) and its parent analogue MIL-53(Fe), prepared by means of a simple hydrothermal method. Various characterization methods were carried out, such as x-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), CO 2 temperature-programmed desorption (CO 2 -TPD), and x-ray photoelectron spectroscopy (XPS), to provide an exegesis regarding the physicochemical properties of the solids.…”

Highly Active and Sulfur‐Resistant Fe–N4 Sites in Porous Carbon Nitride for the Oxidation of H2S into Elemental Sulfur

“…[17,18] Recently, metal-organic frameworks (MOFs) containing isolated Fe-Oχ sites were explored as novel catalysts for oxidative desulfurization. [19,20] Compared with traditional ironbased materials, the Fe atoms of MOFs, which are bonded by organic ligands, are maximally dispersed, and there is ample presence of confined iron sites. [21,22] Despite the high activity and good sulfur resistance of the iron sites, these catalysts are restricted in application because they are water sensitive and time consuming to prepare.…”