Faculty of Chemistry, Adam Mickiewicz University in Poznan, Uniwersytetu Poznanskiego 8, 61-614 Poznan, Poland.
Int J Mol Sci. 2023 Jan 23;24(3):2252. doi: 10.3390/ijms24032252.
The aim of this study was to get insight into the pathway of the acetaldehyde formation from ethanol (the rate-limiting step in the production of 1,3-butadiene) on Cu-SBA-15 and Cu-MnSBA-15 mesoporous molecular sieves. Physicochemical properties of the catalysts were investigated by XRD, N ads/des, Uv-vis, XPS, EPR, pyridine adsorption combined with FTIR, 2-propanol decomposition and 2,5-hexanedione cyclization and dehydration test reactions. Ethanol dehydrogenation to acetaldehyde (without and with oxygen) was studied in a flow system using the FTIR technique. In particular, the effect of Lewis acid and basic (Lewis and BrØnsted) sites, and the oxygen presence in the gas reaction mixture with ethanol on the activity and selectivity of copper catalysts, was assessed and discussed. Two different reaction pathways have been proposed depending on the reaction temperature and the presence or absence of oxygen in the flow of the reagents (via ethoxy intermediate way at 593 K, in ethanol flow, or ethoxide intermediate way at 473 K in the presence of ethanol and oxygen in the reaction mixture).
本研究旨在深入了解乙醇（1,3-丁二烯生产的限速步骤）在 Cu-SBA-15 和 Cu-MnSBA-15 介孔分子筛上形成乙醛的途径。通过 XRD、N 吸附/解吸、Uv-vis、XPS、EPR、吡啶吸附结合 FTIR、2-丙醇分解和 2,5-己二酮环化和脱水测试反应研究了催化剂的物理化学性质。使用 FTIR 技术在流动系统中研究了乙醇脱氢生成乙醛（有氧和无氧）。特别评估并讨论了路易斯酸和碱性（路易斯和布朗斯台德）位以及气体反应混合物中存在氧气对铜催化剂活性和选择性的影响。根据反应温度以及试剂流中是否存在氧气（在 593 K 时通过乙氧基中间途径，在乙醇流中，或在 473 K 时在存在乙醇和氧气的反应混合物中通过乙氧基中间途径），提出了两种不同的反应途径。
