Materials Science &Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6133.
Energy &Transportation Science Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831.
Sci Rep. 2014 Nov 28;4:7238. doi: 10.1038/srep07238.
Our first-principles density functional theoretical modeling suggests that NO oxidation is feasible on fully oxidized single θ-Al2O3 supported platinum atoms via a modified Langmuir-Hinshelwood pathway. This is in contrast to the known decrease in NO oxidation activity of supported platinum with decreasing Pt particle size believed to be due to increased platinum oxidation. In order to validate our theoretical study, we evaluated single θ-Al2O3 supported platinum atoms and found them to exhibit remarkable NO oxidation activity. A comparison of turnover frequencies (TOF) of single supported Pt atoms with those of platinum particles for NO oxidation shows that single supported Pt atoms are as active as fully formed platinum particles. Thus, the overall picture of NO oxidation on supported Pt is that NO oxidation activity decreases with decreasing Pt particle size but accelerates when Pt is present only as single atoms.
我们的第一性原理密度泛函理论模型表明，NO 氧化在完全氧化的单θ-Al2O3 负载的铂原子上是可行的，通过一种改进的 Langmuir-Hinshelwood 途径。这与众所周知的随着 Pt 颗粒尺寸的减小，负载的铂的 NO 氧化活性降低形成对比，据信这是由于铂的氧化增加所致。为了验证我们的理论研究，我们评估了单θ-Al2O3 负载的铂原子，发现它们表现出显著的 NO 氧化活性。对单负载 Pt 原子和铂颗粒的 NO 氧化的周转率（TOF）进行比较表明，单负载 Pt 原子与完全形成的铂颗粒一样活跃。因此，负载 Pt 上的 NO 氧化的总体情况是，随着 Pt 颗粒尺寸的减小，NO 氧化活性降低，但当 Pt 仅以单原子形式存在时，NO 氧化活性会加速。
