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Cu6Sn5-xAg alloys (x = 0, 3, 6; %, mass fraction) were synthesized using Ag as a dopant through a high-temperature melting technique. The microstructure of the alloy was analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), and other equipment, while the hardness of the alloy was measured to investigate the impact of Ag addition on the structure and microstructure of the Cu6Sn5 intermetallic compound. This study explored the influence of varying Ag contents on the properties of Cu6Sn5 intermetallic compounds, with calculations based on first principles revealing the mechanical properties and density of states of η′-Cu6Sn5 and its Ag-doped systems. The results indicated that Cu6Sn5-xAg alloys predominantly existed in three distinct forms, all exhibiting large masses without any impurities or precipitates. First-principle calculations demonstrated that Ag substitution in certain sites suppressed the anisotropy of the Young's modulus of Cu6Sn5, particularly in the Cu1, Cu3, Sn1, and Sn3 positions, while the effect was less significant at the Cu2, Cu4, and Sn2 sites. The introduction of Ag through doping enhanced the covalent bonding within the η′-Cu6Sn5 structure, promoting the formation of a stable (Cu, Ag)6Sn5 structure. [ABSTRACT FROM AUTHOR]

The deep removal of thiophene sulfur from coke oven gas (COG) is an important aspect for the subsequent production of COG to natural gas via methanation. In this process, copper-based sorbents exhibit excellent desulfurization activity. However, the activity of the sorbent depends largely on the interaction between Cu and Zn in the sorbent, which is often used to stabilize metal particles and regulate the activity and stability of the sorbent. Despite a large number of studies on metal-support interaction, there is still a lack of understanding of the effects of metal-support interaction of different strengths on the structure and performance of sorbents. In this work, Cu/ZnO sorbents with different strengths of metal-support interaction were successfully synthesized to elucidate the effect of the interaction between Cu and Zn on the performance of thiophene removal. The reconstruction process of the sorbent (different component ratios) changed the Cu Zn interaction. For weakly interacting sorbents, the reconstruction process enhanced the interaction between the two components, which is conducive to electron transfer and overall activity improvement. On the contrary, for sorbents with strong interaction, the reconstruction process was hindered. • Cu/ZnO is an excellent sorbent for thiophene removal from coke oven gas. • The interaction between Cu and ZnO could be cotrolled by Cu–Zn atomic ratio. • The CZ 1.00 sorbent with Cu–Zn atomic ratio of 1.00 has the best desulfurization performance. [ABSTRACT FROM AUTHOR]

• Cu/ZnO/Al 2 O 3 /ZrO 2 sorbent exhibited high activity and large sulfur capacity in reactive adsorption desulfurization. • The breakthrough adsorption capacity for thiophene could reach up to 36.24 mg/g. • The large number of Lewis acid sites on the sorbent surface facilitated the adsorption of thiophene and the breaking of C-S bonds. • The introduction of zirconium significantly improved the ability of the sorbent surface to activate and dissociate H 2. • Regulating the zirconium content not only improved the dispersion of the Cu species and the interaction between Cu-Zn, but also maintained the particle size of the Cu species during the reaction. The ultra-deep removal of thiophene from coke oven gas (COG) is critical for the conversion of COG to methane. Currently, Cu/ZnO/Al 2 O 3 is considered as a promising sorbent for thiophene removal; however, its desulfurization performance is currently unable to meet the requirements for industrial applications. Here, a zirconium modification strategy is proposed to overcome this problem, allowing zirconium loaded copper-based sorbents (Cu/ZnO/Al 2 O 3 /ZrO 2) with significantly improved thiophene removal performance and high activity to be obtained. Characterization results showed that zirconium improved both the dispersion of copper and the concentration of Lewis acid sites on the sorbent surface. A ZrO 2 concentration of 2 % resulted in stronger Cu-Zn interaction, and the dispersion of Cu on the surface of the sorbent reached its maximum value (49.20 %). Additionally, the Lewis acid strength was also maximized, which greatly improved the desulfurization activity and resulted in a breakthrough adsorption capacity of thiophene (Q b-thiophene) of 36.24 mg/g, which was about 17 % higher than that of the unmodified Cu/ZnO/Al 2 O 3 sorbent. These results demonstrate that the sulfur capacity of the sorbent can be increased by increasing the number of acidic sites on its surface, paving the way for ultra-deep thiophene removal in industrial applications. [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] • Heat treatment on precursor is a suitable way to regulate the Cu-Zn interaction. • Stronger Cu-Zn interaction could improve the desulfurization performance. • The breakthrough adsorption capacity for thiophene could reach up to 25.1 mg/g. The ultra-deep removal of thiophene is a necessary process for the coke oven gas (COG) to methane technology via methanation. It is usually carried out using copper-zinc (Cu-Zn) based sorbent, which was reported to has excellent desulfurization performance, however the effect of Cu-Zn interaction on the desulfurization activity of the sorbent is still need to be further understood. Here, the sorbent precursor was prepared via co-precipitation method, and it was treated at different temperatures to obtain a series of sorbents with different Cu-Zn interaction. The fixed bed reactor was used to evaluate the desulfurization performance, the XPS and H 2 -TPR was carried out to determine the Cu-Zn interaction in sorbents, and the N 2 adsorption, XRD, N 2 O adsorption, FT-IR were used to characterize the physical and chemical properties of samples. The results show that the Cu-Zn interaction could be effectively controlled by heat treatment temperature. At 300 °C, the sorbent precursor would be easily transformed into Cu-Zn solid solution, where the Cu-Zn interaction is strong, and the dispersion of Cu on the sorbent surface is maximized (16.0 %). Those greatly increase the desulfurization activity, and the breakthrough adsorption capacity for thiophene could reach up to 25.1 mg/g. At 250 °C, the temperature is not enough for the transforming of sorbent precursor into Cu-Zn solid solution, so that the breakthrough adsorption capacity for thiophene is only 12.4 mg/g. Whereas, when the temperature is higher than 350 °C, the Cu-Zn solid solution would be further transformed into CuO and ZnO, which significantly decreases the desulfurization activity. In addition, the density functional theory (DFT) calculation results provide further evidence that strong Cu-Zn interaction is beneficial to the desulfurization behavior of sorbent. This work provides both theoretical guidance for promoting the desulfurization performance of copper-based sorbents. [ABSTRACT FROM AUTHOR]

Adsorption desulfurization processes employing zeolites as sorbents are considered to be prospective desulfurization methods owing to their cost-effectiveness. Y zeolites modified with Cu and Ce have excellent adsorption capacity and selectivity for adsorption desulfurization. However, the effect of using different metal precursors on the active sites of these sorbents and their adsorption desulfurization performance still remains ambiguous, which impedes the development of improved desulfurization adsorbents. Herein, Cu(NO 3) 2 , Cu(Ac) 2 , and CuSO 4 were selected as Cu precursors to prepare a series of CuCeY from CeY zeolite. Desulfurization experimental results indicate that outstanding breakthrough adsorption capacities for thiophene (ca. 6.25 mg·g−1) with benzene as the solvent were achieved by the CuCeY A. The interaction between the Cu Ce metals was beneficial for enhancing the electron transfer between Cu2++Ce3+/Ce4++Cu+. Moreover, using different copper precursors significantly changed the redox ability of the adsorbent surface. Changing the copper precursor also had a significant effect on the locations of Cu and Ce ions, and using Cu(Ac) 2 as a metal precursor facilitated the migration of Cu+ (53.6%) and cerium species (35.9%) to the supercage. In situ infrared characterization showed that the oligomerization of thiophene on CuCeY A was significantly restricted due to the lowest B acid content (11.85%) in the CuCeY A. [Display omitted] • A series of CuCeY have been prepared by a variety of Cu precursors. • CuCeY A prepared using Cu(Ac) 2 exhibits the excellent desulfurization performance. • Cu(Ac) 2 as precursor affected the chemical speciations and location of Cu and Ce. • Thiophene oligomerization can be significantly restricted on CuCeY A. [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]