Herzing Andrew A, Kiely Christopher J, Carley Albert F, Landon Philip, Hutchings Graham J
Center for Advanced Materials and Nanotechnology, Lehigh University, 5 East Packer Avenue, Bethlehem, PA 18015-3195, USA.
Science. 2008 Sep 5;321(5894):1331-5. doi: 10.1126/science.1159639.
Gold nanocrystals absorbed on metal oxides have exceptional properties in oxidation catalysis, including the oxidation of carbon monoxide at ambient temperatures, but the identification of the active catalytic gold species among the many present on real catalysts is challenging. We have used aberration-corrected scanning transmission electron microscopy to analyze several iron oxide-supported catalyst samples, ranging from those with little or no activity to others with high activities. High catalytic activity for carbon monoxide oxidation is correlated with the presence of bilayer clusters that are approximately 0.5 nanometer in diameter and contain only approximately 10 gold atoms. The activity of these bilayer clusters is consistent with that demonstrated previously with the use of model catalyst systems.
吸附在金属氧化物上的金纳米晶体在氧化催化方面具有特殊性能，包括在室温下一氧化碳的氧化，但在实际催化剂上众多存在的物种中识别出活性催化金物种具有挑战性。我们使用了像差校正扫描透射电子显微镜来分析几种氧化铁负载的催化剂样品，从那些几乎没有活性或没有活性的样品到具有高活性的样品。一氧化碳氧化的高催化活性与直径约为0.5纳米且仅包含约10个金原子的双层簇的存在相关。这些双层簇的活性与先前使用模型催化剂体系所证明的活性一致。
