October 19-21, 2006

Short Course: XAFS Studies of Nanocatalysis and Chemical Transformations

The short course in x-ray absorption fine-structure (XAFS) analysis, emphasizing problem-solving methods in typical catalysis applications, was offered on October 19-21 at the NSLS. It continued the annual NSLS tradition of gathering a group of scientists, active in the field, who share their expertise with those interested in learning about the possible use of XAFS in their research as well as with those who are relatively advanced. The latest two courses were organized and co-sponsored by the U.S. Department of Energy’s Synchrotron Catalysis Consortium (SCC). The theme of the latest course was tailored to users of the SCC who have recently collected data in systems of relevance for catalysis applications: nanoparticles, mono- and bimetallic (including core-shell), supported on different surfaces, studied ex situ or in situ. The latter included real-time reactions studied at the SCC facilities by XAFS.

Participants in the XAFS Studies of Nanocatalysis and Chemical Transformations Short Course.

The course was organized by Anatoly Frenkel (Yeshiva University), Syed Khalid (NSLS), and Faisal Alamgir (NIST). The format of the course consisted of lectures in the morning and data analysis sessions in the afternoon. Most lectures were designed as tutorials on different aspects of XAFS analysis, such as the “Theory of XANES” and “Theory of EXAFS” (Josh Kas, University of Washington), advanced data analysis methods (Principal Component Analysis, by Stephen Wasserman, SGX Pharmaceuticals), and the basics of EXAFS data processing and fitting (Scott Calvin, Sarah Lawrence College). In addition, lecture topics included the “Concepts of advanced EXAFS data modeling” (Anatoly Frenkel), “In situ XAFS studies of fuel cell catalysts” (Carlo Segre, IIT), “XAFS studies of battery materials” (Faisal Alamgir), and “New opportunities with Quick XAFS at the NSLS” (Syed Khalid).

There were 26 registered participants from academia, industry, and national laboratories, as well as 5-10 graduate students from Stony Brook University and Yeshiva University who audited the course. The lecturers were also the data analysis session instructors. During the data analysis session, participants were trained in using the XAFS analysis packages IFEFFIT (authors: M. Newville and B. Ravel), FEFF8 (authors: J. Rehr, et al) and PCA software (author: S. Wasserman).

Most of the course participants brought their own data they recently collected at the NSLS or other synchrotrons. The analysis sessions were organized by matching instructors to the problems. Instructors rotated between sessions, thus sharing their expertise with more than one group of participants. For example, all groups benefited from Steve Wasserman’s tutorials on the use of his Principal Component Analysis program and Josh Kas’ tutorials of modeling in-situ XANES data in nanoparticles with FEFF8. Scott Calvin, Faisal Alamgir, and Carlo Segre advised all those interested in adaptation of IFEFFIT programs to advanced modeling methods. Anatoly Frenkel helped those studying monometallic and bimetallic, including core/shell, nanoparticles.

All course members thoroughly enjoyed friendly and professional logistical support by the NSLS Users Administration Office: Gretchen Cisco, Liz Flynn, Kathy Nasta, and Mercy Baez.

RELATED LINKS: Workshop Website

ARTICLE BY: Anatoly Frenkel