Temperature-programmed desorption (TPD) and isotopicaly labeled oxygen
-exchange studies were performed over titania-supported vanadia cataly
sts and bare titania support. The catalysts were characterized using B
ET surface area analysis, X-ray diffraction, laser Raman spectroscopy,
scanning electron microscopy, X-ray photoelectron spectroscopy, and t
hermal analysis techniques. The TPD experiments were performed over bo
th the catalyst and the bare support using NO and NHS as adsorbates. T
he exchange reactions performed were: [(NO)-N-14-O-16]->[(NO)-N-15-O-1
8] and [O-16(2)] ->[(18)O2]. Transient experiments, which involved ste
p changes such as [NH3+O-2]->[O-2] were also performed to observe the
transient behavior of various products. These results were combined wi
th the earlier work, and conclusions were drawn regarding the adsorpti
on/desorption and exchange characteristics of these catalysts in the S
CR reaction.