Direct Reduction of Sulfur Dioxide to Elemental Sulfur with Hydrogen over Sn−Zr-Based Catalysts

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• 作者：Gi Bo Han ; No-Kuk Park ; Suk Hoon Yoon ; Tae Jin Lee ; Gui Young Han
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2008
• 出版时间：July 16, 2008
• 年：2008
• 卷：47
• 期：14
• 页码：4658 - 4664
• 全文大小：366K
• 年卷期：v.47,no.14(July 16, 2008)
• ISSN：1520-5045

文摘

We conducted the SO₂ reduction with H₂ over Sn−Zr-based catalysts for the direct sulfur recovery process. The reaction temperature was varied from 250 to 550 °C while using SnO₂-only, ZrO₂-only, and SnO₂−ZrO₂ (Sn/Zr = 2/1) catalysts. The highest reactivity was obtained using the SnO₂−ZrO₂ (Sn/Zr = 2/1) catalyst at 550 °C, for which the SO₂ conversion and sulfur selectivity were 98 and 55%, respectively. Also, the following mechanistic pathway was suggested: (1) The elemental sulfur is produced by the direct conversion of SO₂ according to the redox mechanism (SO₂ + 2H₂ → S + 2H₂O). (2) The produced sulfur is partially converted into H₂S with the hydrogenation (H₂ + S → H₂S). (3) Finally, the Claus reaction proceeds through Lewis and Brönsted acidic sites (SO₂ + 2H₂S → 3S + 2H₂O). It was estimated that the lattice oxygen vacancies might be active sites for the redox mechanism and the Lewis and Brönsted acidic sites might be related to the pathway of the Claus reaction.