Early and late transition metals are often combined as a strategy to tune the selectivity of catalysts for the conversion of syngas (CO/H₂) to C₂₊ oxygenates, such as ethanol. Here we show how the use of a highly reducible Fe₂O₃ support for Rh leads to the in situ formation of supported FeRh nanoalloy catalysts that exhibit high selectivity for ethanol synthesis. In situ characterizations by X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS) reveal the coexistence of iron oxide, iron carbide, metallic iron, and FeRh alloy phases depending on reaction conditions and Rh loading. Structural analysis coupled with catalytic testing indicates that oxygenate formation is correlated to the presence of FeRh alloys, while the iron oxide and carbide phases lead mainly to hydrocarbons. The formation of nanoalloys by in situ reduction of a metal oxide support under working conditions represents a simple approach for the preparation bimetallic catalysts with enhanced catalytic properties.

中文翻译：

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FeRh纳米合金的原位形成用于含氧化合物的合成

通常将早期和晚期过渡金属结合起来作为一种策略，以调节催化剂将合成气（CO / H ₂）转化为C ₂₊含氧化合物（例如乙醇）的选择性。在这里，我们显示了对Rh使用高度还原性的Fe ₂ O ₃载体如何导致原位形成负载的FeRh纳米合金催化剂，该催化剂对乙醇合成具有很高的选择性。原位X射线衍射（XRD）和X射线吸收光谱（XAS）表征表明，取决于反应条件和Rh负载，氧化铁，碳化铁，金属铁和FeRh合金相共存。结构分析加上催化测试表明，含氧化合物的形成与FeRh合金的存在有关，而氧化铁和碳化物相主要导致烃。通过在工作条件下原位还原金属氧化物载体形成纳米合金代表了一种制备具有增强催化性能的双金属催化剂的简单方法。