A new procedure based on the electroless reduction of PdCl2 using Sn(II) as
reducing agent is reported to efficiently add a controlled amount of Pd to
nanoscaled SnO2 powders. The characterization of these powders using XRD,
Raman spectroscopy, XPS, ICP, and TEM is presented and discussed in order t
o show the feasibility of the proposed catalyst addition mechanism as a use
ful tool for the improvement of existing catalytic materials for gas sensor
s. Several palladium salt concentrations and reducing agent ratios and also
different annealing temperatures have been used to analyze the influence o
n the morphology and composition of the samples. Results showed the presenc
e of uniformly distributed metallic Pd clusters on the SnO2 surface at any
annealing temperature and the formation of well-distributed PdO clusters of
less than 3 nm after annealing at sufficiently high temperature, with inco
rporation in this case of palladium into the nanoscaled SnO2 particles.