A variety of techniques: chemisorptions of hydrogen and carbon monoxid
e, temperature-programmed reduction, X-ray diffraction and neopentane
conversion as a catalytic probe, were employed for characterization of
silica-supported palladium-copper alloys. Pd-Cu/SiO2 catalysts prepar
ed by coimpregnation from aqueous solutions of respective metal chlori
des and reduction at 380-degrees-C for 15 hours exhibit good alloy dis
persion (metal particle size of 2-4 nm) and homogeneity. The selectivi
ty for neopentane isomerization increases with the copper content, ach
ieving the maximum at 50 at % Cu. On the other hand, the increase of t
he Cu content causes a gradual decline of the overall activity and inc
rease of activation energy.