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1688707 
Journal Article 
Morphology control of platinum nanoparticles and their catalytic properties 
Miyazaki, A; Balint, I; Nakano, Y 
2003 
Yes 
Journal of Nanoparticle Research
ISSN: 1388-0764
EISSN: 1572-896X 
5 
1-2 
69-80 
WOS:000183704000010 
Platinum nanoparticles with different morphology were prepared by reduction of K2PtCl4 solution in the presence of different capping polymers. It was found that the shapes and the sizes of the Pt nanocrystals resulted were related to the kind of capping polymer used. When poly(vinylpyrrolidon) (PVP), poly(N-isopropylacrylamide) (NIPA) and sodium poly( acrylate) ( SPA) were used as capping agents, the dominant shapes of the Pt nanocrystals observed by transmission electron microscopy were hexagonal (approximate to62%), square (approximate to67%) and triangular (approximate to41%), respectively. The average sizes of Pt nanocrystals were 6.9, 13.6 and 14.6 nm for capping polymers of PVP, NIPA and SPA, respectively. The colloidal Pt nanoparticles with different morphologies were supported on gamma-Al2O3 (1 wt.% Pt) and then their catalytic activity for NO reduction by CH4 was tested in the 350 - 600degreesC temperature range. Additionally, the catalytic activities of these alumina-supported Pt nanocrystals were compared with a conventional catalyst having the average size of Pt particles of approximate to2.4 nm. Over the alumina-supported Pt nanocrystals as compared with the conventional Pt/Al2O3, it was observed that the NO/CH4 reaction yields to NH3 and CO decreased significantly and on the other hand, the yield to N2O increased. The experimental results are suggesting that the catalytic behavior can be tuned in a convenient way through the morphological control of the metal nanoparticles. 
morphology control; metal nanoparticles; NOx reduction by CH4; capping polymer; Pt; Pt/Al2O3