NOVEL TEMPLATING FABRICATION OF NANO-STRUCTURED PT CLUSTERS AND WIRESIN THE ORDERED CYLINDRICAL MESOPORES OF FSM-16 AND THEIR UNIQUE PROPERTIES IN CATALYSIS AND MAGNETISM
M. Sasaki et al., NOVEL TEMPLATING FABRICATION OF NANO-STRUCTURED PT CLUSTERS AND WIRESIN THE ORDERED CYLINDRICAL MESOPORES OF FSM-16 AND THEIR UNIQUE PROPERTIES IN CATALYSIS AND MAGNETISM, MICROPOROUS AND MESOPOROUS MATERIALS, 21(4-6), 1998, pp. 597-606
The robust trigonal prismatic cluster anions such as [Pt-3(CO)(6)](5)(
2-) and [Pt-3(CO)(6)](6)(2-) were selectively synthesized in the order
ed hexagonal channels (2.8 and 4.7 nm diameter) of FSM-16 and ZrO2-mod
ified FSM-16 by a 'ship-in-bottle' technique in the reductive carbonyl
ation of H2PtCl6 with CO+H2O at 323 K. The cluster anions were charact
erized by FTIR, UV-visible, TEM and EXAFS spectroscopy. The Zr oxide-m
odified FSM-16 was prepared by CVD method using Zr(2-propoxyl)(4) impr
egnated with FSM-16, followed by calcination at 723 K. The controlled
removal of CO from [Pt-3(CO)(6)](5)(2-) and [Pt-3(CO)(6)](6)(2-) in FS
M-16 by thermal evacuation at 300-423 K yields nanostructured Pt clust
ers of 1.5-2 nm diameter highly dispersed in the channels of FSM-16. B
y contrast, Pt nano-wires were prepared by a templating reduction of P
t salts impregnated in FSM-16 (2.8 and 4.7 nm) under photo- and gamma-
ray irradiation (see Scheme 1). They exhibited unique properties in CO
chemisorption and magnetism due to their anisotropic morphology of Pt
nano-wires aligned in the ordered mesoporous channels of FSM-16, whic
h were quite different from those of Pt nano-particles. (C) 1998 Elsev
ier Science B.V. All rights reserved.