کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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76257 | 49135 | 2007 | 5 صفحه PDF | دانلود رایگان |
A method for the preparation of size-controlled Pt clusters on nanostructured carbon is described. The carbon possesses tunable micro and mesoporosity, and forms an integrated matrix around the size-controlled Pt clusters. The process involves stabilization of Pt clusters in a zeolite host, pore-filling of the host with a carbon precursor, pyrolysis and removal of the host. The properties of the catalysts vary over a wide range depending on the precise synthesis conditions. On one end of the spectrum, Pt clusters as small as 1.3 nm (average), with narrow size distribution in intimate contact with a predominantly microporous carbon network are obtained; on the other end, Pt clusters of average size 1.7 nm were obtained within a hybrid microporous/mesoporous carbon matrix. Low-angle X-ray diffraction shows periodic nanostructuring (d ∼ 1.4 nm) for Pt/C with Pt loadings ⩽17 wt.%, which is confirmed by TEM imaging. Electrochemical evaluation showed these catalysts to have high electro-active surface areas, and to be at least as active as a commercial Pt/C in the reduction of oxygen.
Journal: Microporous and Mesoporous Materials - Volume 101, Issue 3, 20 April 2007, Pages 440–444