TY - JOUR
T1 - Applications of X-ray absorption fine structure (XAFS) spectroscopy in fuel science
AU - Chen, Yongsheng
AU - Xie, Chao
AU - Song, Chunshan
AU - Wanjala, Bridgid N.
AU - Fang, Bin
AU - Zhong, Chuan Jian
PY - 2011
Y1 - 2011
N2 - X-ray absorption fine structure (XAFS) refers to the details of how x-rays are absorbed by an atom at energies near and above the core-level binding energies of that atom. XAFS spectra are especially sensitive to the formal oxidation state, coordination chemistry, and the distances, coordination number and species of the atoms immediately surrounding the selected element. Practically, XAFS can be divided into two regions, near-edge region and extended region. The near-edge XAFS, or x-ray absorption near edge structure (XANES), provides information on oxidation state, coordination symmetry, and can be used for identification of different species by fingerprinting. In contrast, extended XAFS, or EXAFS, measures the coordination structure including bond distance and coordination number of neighboring atoms. XAFS has been applied in many fields of research including fuel science. In this talk, two examples are given to illustrate the uniqueness of XAFS spectroscopy. In one example, catalyst deactivation in CeO 2-Al 2O 3 supported Ni catalysts for hydrogen production from steam reforming of liquid hydrocarbons in the presence of sulfur impurities was studied by XANES for a better understanding of sulfur poisoning mechanism. XANES spectroscopy at sulfur K-edge (2472 eV), and carbon K-edge (284.2 eV) was used to identify the sulfur and carbon species in the used catalysts and provided new insight into sulfur poisoning mechanism in steam reforming catalysts. In the other example, structure of a PtNiFe/C cathode electrocatalyst used in PEM fuel cells was probed by EXAFS at Pt L3 edge (11,564 eV).
AB - X-ray absorption fine structure (XAFS) refers to the details of how x-rays are absorbed by an atom at energies near and above the core-level binding energies of that atom. XAFS spectra are especially sensitive to the formal oxidation state, coordination chemistry, and the distances, coordination number and species of the atoms immediately surrounding the selected element. Practically, XAFS can be divided into two regions, near-edge region and extended region. The near-edge XAFS, or x-ray absorption near edge structure (XANES), provides information on oxidation state, coordination symmetry, and can be used for identification of different species by fingerprinting. In contrast, extended XAFS, or EXAFS, measures the coordination structure including bond distance and coordination number of neighboring atoms. XAFS has been applied in many fields of research including fuel science. In this talk, two examples are given to illustrate the uniqueness of XAFS spectroscopy. In one example, catalyst deactivation in CeO 2-Al 2O 3 supported Ni catalysts for hydrogen production from steam reforming of liquid hydrocarbons in the presence of sulfur impurities was studied by XANES for a better understanding of sulfur poisoning mechanism. XANES spectroscopy at sulfur K-edge (2472 eV), and carbon K-edge (284.2 eV) was used to identify the sulfur and carbon species in the used catalysts and provided new insight into sulfur poisoning mechanism in steam reforming catalysts. In the other example, structure of a PtNiFe/C cathode electrocatalyst used in PEM fuel cells was probed by EXAFS at Pt L3 edge (11,564 eV).
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M3 - Conference article
AN - SCOPUS:84861017390
SN - 0065-7727
JO - ACS National Meeting Book of Abstracts
JF - ACS National Meeting Book of Abstracts
T2 - 242nd ACS National Meeting and Exposition
Y2 - 28 August 2011 through 1 September 2011
ER -