Copper-Promoted ZnO/SiO2 Regenerable Sorbents for the Room Temperature Removal of H2S from Reformate Gas Streams

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• 作者：Priyanka Dhage ; Alexander Samokhvalov ; Divya Repala ; Evert C. Duin ; Michael Bowman ; Bruce J. Tatarchuk
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2010
• 出版时间：September 15, 2010
• 年：2010
• 卷：49
• 期：18
• 页码：8388-8396
• 全文大小：295K
• 年卷期：v.49,no.18(September 15, 2010)
• ISSN：1520-5045

文摘

The Cu−ZnO/SiO₂ sorbent for ultradeep adsorptive removal of H₂S from the reformate streams at room temperature was prepared and tested, and characterization of the active sites was performed. The Cu dopant significantly enhances desulfurization capacity of ZnO/SiO₂ sorbent at room temperature (up to 92% utilization of ZnO), and the sorbent maintains a high sulfur uptake capacity upon multiple cycles (up to 10) of regeneration by a simple thermal oxidation in air. The “as-prepared” (“calcined”) sorbent contains Cu in the Cu²⁺ form, O, Si, and Zn as ZnO, while the “spent” (“sulfided”) sorbent contains Cu, O, Si, S, and Zn as the ZnS form, as found by XPS. XRD suggests that both zinc and copper compounds of the Cu−ZnO/SiO₂ sorbent are nanodispersed. ESR spectroscopy found that the “calcined” and “sulfided” Cu−ZnO/SiO₂ sorbents contain Cu²⁺ in the single dispersion and coordination state. During H₂S adsorption, partial reduction of Cu²⁺ to Cu⁺ occurs: the higher Cu concentration in the sorbent, the lower the reduction yield of Cu²⁺ to Cu⁺, thus correlating with sulfur uptake capacity. The “deactivated” sorbent (10−11 adsorption/regeneration cycles) is enriched with a different chemical form of Cu²⁺, compared to the “as-prepared” sorbent.