Background: In comparison with these platinum group metal catalysts, supported nano gold catalysts
have emerged as a new type of catalysts highly active at low temperature and selective for the aerobic oxidation
of alcohols. But catalytic data and detailed characterizations of the Au-Ag bimetal catalytic system are not available
up to date.
Objective: This work is aimed to develop bimetallic AuAg-based heterogeneous catalysts for liquid phase selective
oxidation of n-octanol. Modification of the titania support with transition metal additives were used as tools
for transforming active species.
Method: Catalytic tests in n-octanol liquid-phase oxidation at 80 °C. Catalyst characterization by Transmission
electron microscopy, X-ray diffraction, plasma atomic emission spectroscopy, X-ray photoelectron spectroscopy,
EXAFS and UV-visible spectroscopy.
Results and Conclusion: Bimetallic AuAg catalysts supported on titania are moderately active for liquid phase
selective oxidation of n-octanol. Formation of Au-Ag alloy was observed. Their activity may be increased by
modification of the support with donor additives (La, Mg), while acceptor additives (Ce, Fe) decreased it. The
addition of La, that inhibits the formation of Au-Ag alloy, provides the highest activity and the highest stability of
reaction rate with run time in either as prepared and red-ox treated forms, which implies that it stabilizes the active
centers in its optimal electronic state.