Synthesis and Adsorption Desulfurization Performance of Modified Mesoporous Silica Materials M-MCM-41 (M = Fe, Co, Zn)

Abstract

Adsorption desulfurization is a potential new method for deep desulfurization of fuel oil. The development of adsorbents with high adsorption capacity and selectivity is the core of deep adsorption desulfurization. The adsorption behavior of thiophene in MCM-41 mesoporous materials modified by various metal ions was studied in order to understand the adsorption desulfurization process of molecular sieves. The Fe-, Co-, and Zn-modified MCM-41 materials were prepared using a one-step in situ hydrothermal synthesis method. The modified MCM-41 molecular sieves maintained the mesoporous structure, and the metal ions had specific dispersion on the surface of the molecular sieves. Adsorption of thiophene on the surfaces of molecular sieves had both physical and chemical characteristics. The adsorption desulfurization performance of the modified molecular sieve was superior to that of the pure silica molecular sieve. In the simulated gasoline with sulfur content of 220 μg/g, when the amount of adsorbent used was 100 mg, the adsorptive desulfurization performance tended to be in equilibrium, and the optimum adsorption temperature was 30°C. Fe-MCM-41 and MCM-41 molecular sieves reached adsorption equilibrium after ~60 min, but the desulfurization rate of Co-MCM-41 and Zn-MCM-41 still increased slightly. The kinetic simulation results indicated that the pseudo-second-order kinetics adsorption model described well the adsorption process of thiophene on molecular sieves. The molecular sieve Fe-MCM-41 had the best desulfurization performance with an equilibrium adsorption capacity of 14.02 mg/g and the desulfurization rate was ~90%.

Synthesis of MCM-41 Silica Mesoporous Modified with Zn Metal

“…The same thing was also reported by Admi et al [23] that the Zn ion in the MCM-41 framework influences the form of weak electrostatic repulsion so that the particle size tends to be smaller. EDS analysis can be implemented to determine the chemical composition and distribution of Zn metal in the MCM-41 [24]. The results of the EDS analysis are shown in Figure 3.…”

Low-Temperature Catalytic Oxidation of Glycerol to Glyceric Acid over Zr@MCM-41 Supported Pt Catalyst

“…Because MCM-41 mesoporous zeolite possesses some advantages such as the favorable hydrothermal stabilities, pore structure tunability, functionalized surface acidity, and high surface area [23][24][25][26] , so it often used as support in the catalysis [27][28] . In the MCM-41 mesoporous zeolite supported catalysts, the high dispersion of surface metal species is bene cial to expose the active sites, and in turn improve the catalytic activity of catalysts [29] . Meanwhile, the regular pore size distribution is bene cial to selective catalytic oxidation of substrate [30] .…”

Boosting the Adsorption Performance of Thiophenic Sulfur Compounds with a Multimetallic Dual Metal–Organic Framework Composite

“…The existence of sulfur compounds in fuels as environmental pollutants is a major concern owing to their SO x emissions, which not only leads to acid rain pollution but also is harmful to human health. , As a well-applied industrial desulfurization technology, hydrode­sulfurization is effective only for mercaptans, thioethers, disulfides, and so forth and is almost ineffective for thiophenic sulfur compounds (TSCs). , Therefore, the deep removal of TSCs from fuels is urgent. − So far, some conventional adsorbents, such as activated carbons and zeolites, − have been investigated for adsorption desulfurization, which is regarded as one of the most desired methods for deep desulfurization. − For instance, the zeolites were modified by metal ions (e.g., Cu, Ni, etc. ), alkali treatment, and carbon nanotubes’ enhanced porosity by hybridization with BN to improve performance. − However, the unregulated structure and inadequate specific surface area of the above adsorbents restrict the development for further enhancing the adsorption performance. − MOFs exhibit promising applications in deep desulfurization owing to their rich porous properties, open active sites, and adjustable backbones.…”