Abstract
Alcohols, due to their easy storage and transport, have been proposed as possible
sources of hydrogen. To convert alcohols to hydrogen via onboard reforming requires highly
active, selective and stable catalysts. Pd supported on ZnO has shown promising properties as
a catalyst for onboard steam reforming of methanol to produce hydrogen [1]. The formation of
PdZn alloy nanoparticles has been considered to be responsible for the improved catalytic
performance of Pd/ZnO catalysts [1]. The alloy formation processes and detailed surface
atomic structures of the PdZn nanoparticles, however, are not well understood [2-3]. We have
recently developed a unique model nanocatalyst by preparing precursor materials consisting of
Pd dispersed onto well-defined surfaces of ZnO nanobelts. In situ study of the reduction
processes of the Pd/ZnO precursor materials, using an electron microscope with sub-Ångström
image resolution, has provided deep insights into the PdZn alloy formation processes, their
structural evolution and the nature of the final Pd/ZnO catalysts.
