Abstract:The removal of hydrogen sulfide (H2S) from blast furnace gas is crucial for achieving ultra-low emissions in the iron and steel industry. After passing through the top gas recovery turbine (TRT) unit, the blast furnace gas temperature typically ranges from 50 to 80 ℃. Ferric hydroxide (α-FeOOH) exhibits high activity at low temperatures, making it an ideal adsorbent for H2S after water treatment. α-FeOOH was doped with Zn2+ at different molar ratios (1%, 5%, and 11%) via co-precipitation crystallization. A combined fixed-bed and gas chromatography platform was used to evaluate the H2S adsorption capacity in the simulated blast furnace gas atmosphere. The results showed that the H2S adsorption capacity increased to 292.2 mg/g, a 137% improvement. The physical and chemical properties of the adsorbents were characterized using BET, EPR, and XPS. The results indicated a significant increase in the specific surface area of the Zn/FeOOH samples, rising by approximately 60%. This enhancement leads to more reaction interfaces available for H2S adsorption, providing additional active sites for H2S molecules, which is crucial for improving sulfur capacity. Additionally, the pore volume increased by about 116%, mitigating the pore blockage typically caused by reaction products. All Zn/FeOOH samples displayed characteristic peaks associated with oxygen vacancies at g = 2.002, with the Zn/FeOOH-11 sample showing the highest intensity of the oxygen vacancies. This suggests that Zn doping considerably boosts the oxygen vacancies within the material. The introduction of Zn2+ ions into the α-FeOOH lattice creates local stress and distortion due to the mismatch in ionic radius and charge between Zn2+ and Fe3+. This mismatch facilitates the escape of oxygen atoms, resulting in the formation of oxygen vacancies; these vacancies serve as active sites for the adsorption and activation of H2S molecules, thereby enhancing the catalytic activity of the material. Furthermore, the proportion of monohydroxyl groups in Zn-doped α-FeOOH increased to 36%. These monohydroxyl groups are pivotal for improving sulfur capacity, as they are highly active and can form hydrogen bonds with H2S molecules, further enhancing their adsorption on the material surface. In situ infrared spectroscopy analysis revealed that Zn functions as a catalyst component and also directly interacts with H2S to form ZnS. This Zn doping enhances the catalytic performance of α-FeOOH and influences the types of sulfur products generated. The alterations in structure and surface properties significantly enhance the adsorption and conversion capacity of Zn/FeOOH materials for H2S, providing a reference for increasing the sulfur capacity of the adsorbent and enhancing blast furnace gas purification technologies. Close-