Joy Andrews (SIMES Friday seminar)

Date(s) - Apr 12 2013
11:00 AM - 12:30 PM

Shasta Room, Bldg 40, Room 361


Operando Spectroscopic Nano-imaging of Catalysts

Joy C. Andrews

Staff Scientist, Stanford Synchrotron Radiation Lightsource

Professor of Chemistry, California State University, East Bay


The Fischer-Tropsch-to-Olefins (FTO) process commonly uses an iron-based catalyst, where the addition of promoters can improve catalytic activity and affect selectivity toward light olefins. The active sites are claimed to be located on metal nanoparticles, but their exact chemical nature is still under debate. Recent developments of advanced in situ spectroscopic techniques have proven to be very important for studying the catalyst under working conditions, providing essential insight into structure-performance relationships. Full-field Transmission hard X-ray Microscopy (TXM) is an excellent method because of its potential to image nanoscale features of relatively thick objects (tens of microns), combining chemical and morphological sensitivity, at 30 nm resolution. We have used the TXM technique to collect single-pixel Fe K-edge XANES, using a specially designed reactor to perform operando characterization during catalysis under full reaction conditions including temperature and pressure. Results of Co-based operando FT catalysis will be shown as well.