caa a22 4500 475844521 CHVBK 20180406123910.0 cr unu---uuuuu 170329e20000501xx s 000 0 eng 10.1023/A:1019196908404 doi (NATIONALLICENCE)springer-10.1023/A:1019196908404 Asymmetric pair distribution functions in catalysts [Elektronische Daten] [Bjerne Clausen, Jens Nørskov] The structural parameters, i.e., coordination numbers, bond distances and disorder obtained from the analysis of EXAFS spectra may sometimes be significantly influenced by errors introduced due to the inadequacy of the analysis method applied. Especially in the case of heterogeneous catalysts it has been realized that often there is a need to use an improved EXAFS data analysis compared to the simple harmonic approach which works well for well‐defined bulk structures. This is due to the fact that catalysts contain highly dispersed or disordered structures with pair distribution functions quite different from well‐crystalline bulk materials. In addition, the increased interest for in situ studies, which typically imply high temperatures, makes the influence from anharmonic vibrations on the shape of the pair distribution a significant factor. In this paper, we discuss the importance of asymmetric pair distribution functions for nano‐sized particles and how they influence the structural parameters obtained from the standard data analysis. An alternative method, which takes into account deviations from the Gaussian pair distribution function typically used in the analysis of EXAFS spectra, will be described. The method is based on an analysis of the pair distribution functions derived from molecular dynamics simulations of small metal particles and its reliability is demonstrated by comparing structural parameters obtained from independent X‐ray diffraction experiments. Kluwer Academic Publishers, 2000 EXAFS nationallicence catalysis nationallicence XRD nationallicence molecular dynamics nationallicence asymmetric pair distribution nationallicence anharmonic nationallicence in situ studies nationallicence Clausen Bjerne Haldor Topsøe Research Laboratories, DK‐2800 Lyngby, Denmark aut Nørskov Jens Center for Atomic‐scale Materials Physics, Department of Physics, Technical University of Denmark, DK‐2800 Lyngby, Denmark aut Topics in Catalysis Kluwer Academic Publishers 10/3-4(2000-05-01), 221-230 1022-5528 10:3-4<221 2000 10 11244 https://doi.org/10.1023/A:1019196908404 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1023/A:1019196908404 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Clausen Bjerne Haldor Topsøe Research Laboratories, DK‐2800 Lyngby, Denmark aut NATIONALLICENCE 700 1- Nørskov Jens Center for Atomic‐scale Materials Physics, Department of Physics, Technical University of Denmark, DK‐2800 Lyngby, Denmark aut NATIONALLICENCE 773 0- Topics in Catalysis Kluwer Academic Publishers 10/3-4(2000-05-01), 221-230 1022-5528 10:3-4<221 2000 10 11244 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer