Electroless addition of catalytic pd to SnO2 nanopowders

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.