A. Vazquez et al., HIGH-RESOLUTION ELECTRON-MICROSCOPY CHARACTERIZATION OF SULFIDED PALLADIUM PARTICLES ON AMORPHOUS SIO2, Catalysis letters, 28(2-4), 1994, pp. 351-360
The microstructure of palladium particles deposited on a porous silica
support was examined by high resolution microscopy following various
sulfidation treatments. For catalysts sulfided by the reaction itself
(hydrodesulfurization of thiophene), the micrographs show large partic
les where an amorphous sulfide layer surrounds the Pd core; in the cas
e of small particles, the presence of PdS2 was identified. For catalys
ts sulfided under 20% H2S/H-2 at 623 K, the particles show lattice pla
nes compatible with PdS2 and PdS. By increasing the sulfidation temper
ature to 723 K, faceted PdS particles are mostly formed. Some structur
al defects related to the sulfidation treatment are also shown.