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NaY and Na13X zeolites were modified by different modification manners including H + modification, metal ion modification (Cu 2+ , Ni 2+ , or Ce 3+ ), and H + modification followed by metal ion modification to investigate their deep desulfurization behavior in gasoline. The sorbents were characterized by X-ray diffraction, FTIR of chemisorbed pyridine, N 2 adsorption, and scanning electron microscope (SEM). The desulfurization performance of these sorbents was evaluated in model gasoline containing thiophene and cyclohexane with thiophene concentration of 500 mg/L, and the results were analyzed to investigate the effect of preparation methods on adsorption desulfurization behavior. The result indicates that H + modification or metal ion modification could all improve the desulfurization performance of both NaY and Na13X zeolites, except for Na13X modified by Cu 2+ and Ni 2+ . For Cu 2+ or Ni 2+ ion exchanging, the crystal structure of Na13X would be destroyed, resulting in a much lower desulfurization efficiency than that of the parent Na13X. The desulfurization efficiency of sorbents prepared via H + modification followed by metal ion modification is higher than that of sorbents prepared by single H + modification or single metal ion modification, because the former is more conducive to improve the content of metal elements on the sorbents than the latter. In addition, the increase of the specific surface area and pore volume of the sorbents would directly lead to the improvement of desulfurization performance of the sorbents. Compared with Na13X, the H + modification on NaY zeolite can significantly enhance the desulfurization performance of the sorbents. Among those prepared sorbents, the CuHY has the highest desulfurization efficiency. The influence of thiophene concentration (100-1000 mg/L) on desulfurization efficiency of CuHY sorbent was evaluated. The results indicate that the desulfurization efficiency of CuHY sorbent is nearly 100% at room temperature, when the thiophene concentration is lower than 300 mg/L. Moreover, its desulfurization behavior could be described by Langmuir isothermal equation. Graphic abstract .

The commercial NaY zeolite with the Si/Al ratio of 5:1 was selected and modified for researching the adsorptive removal of thiophene from benzene. The zeolite was ion-exchanged in Ce(NO3)3 solution and then calcined in muffle to prepare the CeY sorbent. The results show that it is a suitable method to prepare the sorbent removing thiophene from benzene that NaY zeolite is ion-exchanged by cerium in Ce(NO3)3 solution. The desulfurization efficiency of CeY sorbent increases obviously comparing with NaY zeolite. The effects of the calcination temperature, calcination time, concentration of Ce(NO3)3 solution, ion-exchange time, and ion-exchange times on the desulfurization capacity of CeY sorbent were also studied. The results show that the optimal CeY sorbent can be obtained when NaY zeolite is ion-exchanged in 0.5 mol/L Ce(NO3)3 solution at 100°C for 4 h, calcined at 700°C for 2 h, and repeated the above steps two times. The results of XRD and BET characterization indicate that those preparation conditions mainly influence on the crystallinity, specific surface area of CeY sorbent. The best CeY sorbent can remove thiophene to 136.8 mg/L from 550.0 mg/L in thiophene-benzene solution at ambient temperature and pressure with the agent-liquid ratio of 1:16 (g/mL). [ABSTRACT FROM AUTHOR]

[Display omitted] • Heat treatment and ligand size adjustment could regulate Cu location in Y zeolite. • More copper could be located in supercages, resulting in more absorbed thiophene. • The Cu 10.74 Y 350 sample exhibits excellent desulfurization performance. Y zeolites modified with Cu are promising sorbents for adsorption desulfurization due to their cost-effectiveness. Only the supercage, which is larger than thiophene molecule, is the potential location of active sites for thiophene removal. However, numerous copper species cannot serve as effective active sites due to their inability to be located in the supercages. Based on this consideration, two strategies to regulate Cu location in Y zeolite to address the aforementioned challenges were explored. One is to adjust the molecular size of copper-ammonia ligands through pH value of cuprammonia solution, and the other is to prevent the migration of copper to small cages by heat treatment. The results showed that these two strategies could effectively regulate the location of copper active sites in Y zeolite. During heat treatment, Cu could transfer into supercages from sodalite cages at 350 °C. More effective copper would be targeted to be located in the supercages in the process of adjusting pH. For the best Cu 10.74 Y 350 sorbent, which was prepared at 350 °C under pH of 10.74, the Cu content in the supercages was the highest (25 %), and thus it has an excellent desulfurization efficiency of 82.3 %. [ABSTRACT FROM AUTHOR]

[Display omitted] • H 2 S in BFG could be adsorbed on Na-type FAU zeolite via two different ways. • H 2 S could be adsorbed on bridging hydroxyl groups of Na-type FAU zeolite. • H 2 S could interact with Na+ via base-acid interaction over FAU zeolite. • On Na+, H 2 S would be converted to S and further oxidized to SO 4 2− and S 2 O 3 2− by O 2. The desulfurization of blast furnace gas is crucial to meet the strict requirements for clean production of steel industry. However, the composition of blast furnace gas is complicated, and the gases of H 2 O, CO, CO 2 , and O 2 would significantly affect the desulfurization activity. Therefore, the desulfurization performance for H 2 S in simulated blast furnace gas by Na-type FAU zeolites with different Si/Al was investigated. The physicochemical properties of zeolite sorbents were measured, and their correlation with desulfurization performance was studied. Moreover, the adsorption mechanism of H 2 S was investigated. The breakthrough sulfur capacity improved with the increase of relative crystallinity, Na+ content, specific surface area, and the decrease of Si/Al ratio. The adsorption mechanism of H 2 S on Na-type FAU zeolite was proposed. One is the hydrogen bond interaction between the bridging hydroxyl groups and H 2 S, and the other one is the base-acid interaction between sodium ion and H 2 S. In blast furnace gas, when interacting with Na+, H 2 S would be transformed into S, which further oxidized into thiosulfate and sulfate by O 2. [ABSTRACT FROM AUTHOR]

The ultra-deep removal of thiophene to 0.1 ppmv level is necessary for coke oven gas to methane process. NaY zeolite was reported to have this potential, and acid sites in NaY play an important role on its desulfurization performance. Based on this situation, sorbents with different types and strengths of acids were prepared by modifying NaY in ammonium nitrate and citric acid solutions. Their desulfurization behaviors in simulated coke oven gas were evaluated by fixed bed. The results show that both ammonium nitrate and citric acid modification on NaY are beneficial to the breakthrough adsorption capacity of thiophene (Q b-thiophene). The NaY after modified in 0.10 mol/L citric acid solution has the highest Q b-thiophene at 100 °C. Ammonium nitrate modification could significantly increase medium-strong Bronsted acid in NaY, whereas citric acid modification mainly increases weak Lewis acid. On medium-strong Bronsted acid sites, thiophene polymerization reaction would occur easily, which would result in the obvious decrease of Q b-thiophene from 71.31 to 35.3 mg/g due to the acid sites covering and micropores blocking by thiophene oligomer. The increase of Lewis acid is conducive to desulfurization. Moreover, on Lewis acid site, the temperature region for thiophene removal is wider than that on Bronsted acid. Unlabelled Image • Sorbents for ultra-deep desulfurization was developed by improving acid sites. • NH 4 NO 3 modification increase medium-strong Bronsted acid in NaY. • Citric acid modification mainly increases weak Lewis acid in NaY. • L acid promotes thiophene adsorption, whereas B acid promotes thiophene polymerization. [ABSTRACT FROM AUTHOR]

[Display omitted] • H 2 S could be effectively removed via physical and chemical adsorption on CuX zeolite. • Cu2+ in 13X zeolite could interact with H 2 S to form CuS. • The breakthrough sulfur capacity of Cu 25 X-Ex could reach up to 7.71 g S/100 g sorbent. With the promulgation of new regulations, it's of great significance to desulfurization from blast furnace gas (BFG) to meet the clean production of iron making industry. Among different desulfurization technologies, zeolite-based sorbents are extensively studied due to the easy operation, low operating cost, and long service life. In this research, the 13X zeolite was selected, and it was ion-exchanged by different metal elements (Cu, Zn, Co, Mn) to prepared a series of sorbents. A fixed bed was used to evaluate their desulfurization behavior, and the XRD, SEM, ICP-OES, XPS, N 2 adsorption, and CO 2 -TPD were carried out to characterize the physical and chemical properties of sorbents. The effects of water vapor content and desulfurization temperature on the removal of H 2 S were investigated. The regeneration performance of sorbent was also explored. The results showed that the Cu 25 X-Ex sorbent has the highest breakthrough sulfur capacity of 7.71 g S/100 g sorbent in dry simulated BFG. The breakthrough sulfur capacity of Cu 25 X-Ex was 4.52 g S/100 g sorbent when the water vapor content is 5 %. The CO 2 -TPD results showed that the basic sites were favorable for the adsorption of H 2 S on the surface of zeolite. The XPS results illustrate that the forms of S adsorbed on Cu 25 X-Ex sorbent were CuS, CuS 2 O 3 , and CuSO 4 , so it is suggested that the reaction between adsorbed H 2 S with the metal cations in sorbent occurred subsequently. The research indicated that Cu 25 X-Ex sorbent has potential applicability in the desulfurization of blast furnace gas. [ABSTRACT FROM AUTHOR]

• The texture properties of hierarchical TS-1 zeolites can be precisely modulated by the TritonX homologues with different amounts of ethoxide. • The mesoporosity and Ti content of hierarchical Ti-rich determine the conversion of benzene. • Introducing additional mesoporosity into the hierarchical TS-1 facilitates the direct the oxidation of benzene. The hydrothermal approach was used to effectively synthesis hierarchical TS-1 utilizing the green and inexpensive surfactant TritonX homologues with varying amounts of ethylene oxide groups. The textural property of obtained materials can be modulated by varying the number of ethylene oxide groups of the TritonX homologues. The mesoporous size of hierarchical TS-1 depends on the micelles size of TritonX homologues. The synthesized samples have significant intracrystalline mesopores with a pore size range of 3.5–4.5 nm. The impact of various ethylene oxide group counts of TritonX homologous on the structure, texture properties, and titanium species was investigated using a variety of characterization methods. The hydroxylation of benzene with the H 2 O 2 as oxidizer was used to investigate the catalytic properties of hierarchical TS-1. The catalytic properties and stability of the resulting materials were noticeably improved in the hydroxylation of benzene in comparison with the traditional TS-1. [Display omitted] [ABSTRACT FROM AUTHOR]