Ceria-supported Pd is a promising heterogeneous catalyst for CO oxidation relevant to environmental cleanup reactions. Pd loaded onto a nanorod form of ceria exposing predominantly (111) facets is already active at 50 °C. Here we report a combination of CO-FTIR spectroscopy and theoretical calculations that allows assigning different forms of Pd on the CeO₂(111) surface during reaction conditions. Single Pd atoms stabilized in the form of PdO and PdO₂ in a CO/O₂ atmosphere participate in a catalytic cycle involving very low activation barriers for CO oxidation. The presence of single Pd atoms on the Pd/CeO₂-nanorod, corroborated by aberration-corrected TEM and CO-FTIR spectroscopy, is considered pivotal to its high CO oxidation activity.

中文翻译：

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CeO ₂（111）上原子分散的Pd-O物种作为低温CO氧化的高活性位点

二氧化铈负载的钯是一种有前途的多相催化剂，可用于与环境净化反应有关的一氧化碳氧化。负载在主要暴露于（111）小面的纳米棒形式的二氧化铈上的钯在50°C时已具有活性。在这里，我们报告了CO-FTIR光谱和理论计算的结合，该理论计算允许在反应条件下在CeO ₂（111）表面分配不同形式的Pd 。在CO / O ₂气氛中以PdO和PdO ₂形式稳定的单个Pd原子参与了催化循环，该循环涉及非常低的CO氧化活化能。Pd / CeO ₂上存在单个Pd原子通过像差校正的TEM和CO-FTIR光谱法证实了-nanood对其高CO氧化活性至关重要。