Superoxide Formation on Isolated Cationic Gold Clusters
Superoxide Formation on Isolated Cationic Gold Clusters
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DOI：
10.1002/anie.201402783
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发表时间：
2014-06-01
影响因子：
16.6
通讯作者：
Fielicke, Andre
中科院分区：
文献类型：
--
作者：
Woodham, Alex P.;Fielicke, Andre
已知金纳米粒子是利用分子氧作为原料的高度通用的氧化催化剂，但负责活化氧的机制和种类仍不清楚。研究了无负载的阳离子金簇和分子氧之间的反应。使用红外光谱法在气相中对所得络合物进行了表征。观察到的 v(O-O) 伸缩频率的强烈红移表明超氧 (O-2(-)) 部分的形成。这些部分在系统中自发形成，通过电子转移在球形果冻模型（Au-10（+）和Au-22（+））内获得封闭的壳层，而在其他系统（Au-4（+），Au-12（+），Au-21（+））中观察到氧诱导的活化自促进。
Gold nanoparticles are known to be highly versatile oxidation catalysts utilizing molecular oxygen as a feedstock, but the mechanism and species responsible for activating oxygen remain unclear. The reaction between unsupported cationic gold clusters and molecular oxygen has been investigated. The resulting complexes were characterized in the gas phase using IR spectroscopy. A strong red-shift in the observed v(O-O) stretching frequency indicates the formation of superoxo (O-2(-)) moieties. These moieties are seen to form spontaneously in systems, which upon electron transfer attain a closed shell within the spherical jellium model (Au-10(+) and Au-22(+)), whereas an oxygen induced self-promotion in the activation is observed for other systems (Au-4(+), Au-12(+), Au-21(+)).