Department of Physics, University of Central Florida, Orlando, Florida 32816, USA.
J Am Chem Soc. 2010 Jun 30;132(25):8747-56. doi: 10.1021/ja101997z.
The structure, size, and shape of gamma-Al(2)O(3)-supported Pt nanoparticles (NPs) synthesized by inverse micelle encapsulation have been resolved via a synergistic combination of imaging and spectroscopic tools. It is shown that this synthesis method leads to 3D NP shapes even for subnanometer clusters, in contrast to the raft-like structures obtained for the same systems via traditional deposition-precipitation methods. Furthermore, a high degree of atomic ordering is observed for the micellar NPs in H(2) atmosphere at all sizes studied, possibly due to H-induced surface reconstruction in these high surface area clusters. Our findings demonstrate that the influence of NP/support interactions on NP structure can be diminished in favor of NP/adsorbate interactions when NP catalysts are prepared by micelle encapsulation methods.
采用反胶束包封法合成的γ-Al(2)O(3)负载的 Pt 纳米粒子（NPs）具有特定的结构、尺寸和形状，通过成像和光谱技术的协同组合得到了确定。结果表明，与传统的沉积沉淀法得到的筏状结构相比，即使是亚纳米簇，这种合成方法也能得到 3D 的 NP 形状。此外，在所有研究的尺寸下，在 H(2)气氛中，胶束 NPs 都表现出高度的原子有序性，这可能是由于这些高表面积的团簇中 H 诱导的表面重构。我们的研究结果表明，当采用胶束包封法制备 NP 催化剂时，NP/载体相互作用对 NP 结构的影响可以减小，而有利于 NP/吸附剂相互作用。
