(420d) In Situ Catalytic Monitoring On Pt-Vanadia Nano Systems

Yavuz, C. T., UCSB
Lee, S., Argonne National Laboratory
Lee, B., Argonne National Laboratory
Kim, M. H., UCSB
Baik, J. M., UCSB
Stucky, G., University of California Santa Barbara
Vajda, S., Argonne National Laboratory

Surface X-ray diffraction techniques stand out among the tools to monitor crystal phases in situ while a catalytic reaction is taking place. They are advantageous over in situ transmission electron microscopy (TEM) and low energy electron diffraction (LEED) since they do not require low pressure environments or conductive samples. High intensity x-ray beams available at Synchrotron facilities (especially Grazing Incidence X-Ray Scattering ? GISAXS) are highly precise on the incidental diffractions since it takes less (exposure) time to get data, thus, enabling real time monitoring. They also minimize the damage that comes from the x-ray beam since the contact time between sample and the beam is limited.

Methanol oxidation by vanadium oxides is well studied, hence, serves as a good measure for catalytic activity. Highly ordered arrays of VO2 nanowires grown on r-cut sapphire prove to be unique for the in situ catalytic activity tests. Here, we present size and morphology dependent activity of Platinum coated single crystalline VO2 nanowires in methanol oxidation reactions.