Abstract
Bi has been widely employed as a modifier for Pd and Pt based catalyst mainly in order to improve selectivity.
We found that when Bi was added to the bimetallic system AuPd, the effect on activity in alcohol
oxidation mainly depends on the amount of Bi regardless its position, being negligible when Bi was
0.1 wt% and detectably negative when the amount was increased to 3 wt%. However, the selectivity of
the reactions notably varied only when Bi was deposited on the surface of metal nanoparticles suppressing
parallel reaction in both benzyl alcohol and glycerol oxidation. After a careful characterization of all
the catalysts and additional catalytic tests, we concluded that the Bi influence on the activity of the catalysts
could be ascribed to electronic effect whereas the one on selectivity mainly to a geometric modification.
Moreover, the Bi-modified AuPd/AC catalyst showed possible application in the production of
tartronic acid, a useful intermediate, from glycerol.
