International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
Chem Asian J. 2012 Apr;7(4):802-8. doi: 10.1002/asia.201100949. Epub 2012 Feb 1.
Well-ordered mesoporous Pt nanoparticles (MPNs) with uniform olive shapes are synthesized by using two-dimensional (2D) hexagonal mesoporous silica (SBA-15) as a hard template. The average particle sizes are controllable in the range of 150 to 230 nm by changing the reduction time. Low-angle XRD profiles for the obtained MPNs show three distinct peaks assignable to the (10), (11), and (20) planes of a highly ordered 2D hexagonal symmetry. From high-magnification SEM images, periodically arranged Pt nanowires are observed clearly, which are a negative replica of the 2D hexagonally ordered mesoporous silica (SBA-15). Furthermore, the single crystallinity of the Pt fcc structure coherently extends over the whole particles. As a result of such unique character as well as high surface area, the obtained MPNs show distinctly enhanced electrocatalytic properties for methanol oxidation reaction compared to other Pt samples, such as Pt black.
有序介孔 Pt 纳米粒子（MPNs）具有均匀的橄榄形状，通过使用二维（2D）六方介孔硅（SBA-15）作为硬模板合成。通过改变还原时间，平均粒径可在 150 至 230nm 的范围内进行控制。所得 MPNs 的低角度 XRD 图谱显示三个明显的峰，可归因于高度有序的 2D 六方对称性的（10）、（11）和（20）平面。从高倍 SEM 图像中，可以清楚地观察到周期性排列的 Pt 纳米线，这是二维六方有序介孔硅（SBA-15）的负复制。此外，Pt fcc 结构的单晶性在整个颗粒上一致延伸。由于具有这种独特的特征以及高表面积，与其他 Pt 样品（例如 Pt 黑）相比，所得到的 MPNs 对甲醇氧化反应表现出明显增强的电催化性能。
