Nanoparticles of amorphous ruthenium sulfide easily obtainable from a TiO2-supported hexanuclear cluster complex [Ru6C(CO)16]2-: a highly active catalyst for the reduction of SO2 with H2.
TiO(2)-supported ruthenium-metal particles were derived from an anionic hexanuclear carbido carbonyl cluster [Ru(6)C(CO)(16)](2-) and compared with those prepared conventionally by impregnation of TiO(2) with a solution of RuCl(3) followed by reduction with H(2). The average sizes of the metal particles in both systems are similar, that is, 12 A for molecular cluster-derived particles and 15 A for those derived from the RuCl(3) precursor, although the size distribution is sharper in the former case. These supported particles efficiently promote the reduction of SO(2) with H(2) to give elemental sulfur. Their active form is ruthenium sulfide as confirmed by EXAFS and X-ray diffraction measurements. The nanoscale ruthenium sulfide particles, which originated from the cluster complex, have an amorphous character and show activity even at low temperature (463 K), whereas ruthenium sulfide formed from RuCl(3)-derived metal dispersion is a pyrite-type RuS(2) crystallite and needs a temperature above 513 K to effect the same catalysis. Amorphous ruthenium sulfide maintains its nano-sized scale (approximately 14 A) regardless of the reaction temperature, while RuS(2) crystallite aggregates to form larger nonuniform particles.
RIKEN, The Institute of Physical and Chemical Research, Hirosawa 2-1, Wako-shi, Saitama 351-0198, Japan.
Atsushi
A
Ishiguro
Takayuki
T
Nakajima
Tadahisa
T
Iwata
Masahiro
M
Fujita
Taketoshi
T
Minato
Fumitaka
F
Kiyotaki
Yasuo
Y
Izumi
Ken-ichi
K
Aika
Masaya
M
Uchida
Koji
K
Kimoto
Yoshio
Y
Matsui
Yasuo
Y
Wakatsuki
D002384:Catalysis; D004787:Environmental Pollution / Q000517:prevention & control; D006865:Hydrogenation; D036103:Nanotechnology / Q000379:methods*; D017975:Ruthenium Compounds / Q000737:chemistry; D013440:Sulfides / Q000737:chemistry; D013458:Sulfur Dioxide / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry
D017975:Ruthenium Compounds; D013440:Sulfides; D013458:Sulfur Dioxide; C009495:titanium dioxide; D014025:Titanium