Theory as a driving force to understand reactions on nanoparticles: general discussion

Abstract

opened discussion of the introductory lecture by Bruce Gates: As you have shown, EXAFS plays a crucial role in determining the structure and the nuclearity of nanoparticles (NPs). For each shell, the accuracy of this deter-mination depends on the error bar associated to the coordination number, that strongly correlates with the corresponding Debye-Waller (DW) parameter. This becomes even more important when in situ operando experiments are performed at reaction temperature. Based on your experience, what suggestions can you give to reduce this correlation and increase the potentiality of the technique? Do you believe it is possible to x or to determine, in a reliable way, DW parameters from independent experimental or computational works? Do you believe that in temperature-dependent experiments it is reliable to adopt the Debye or the Ein-stein model 1,2 to parametrize the evolution of DW parameters? 1 G. Dalba, P. Fornasini, R. Grisenti and J.

Inelastic Neutron Scattering Investigation of MgCl2 Nanoparticle-Based Ziegler–Natta Catalysts for Olefin Polymerization

“…The experimental INS spectra were recorded at 15 K using the TOSCA spectrometer at the ISIS spallation Neutron and Muon Source (Rutherford Appleton Laboratory, UK), ,, with a Δ E / E resolution of 2%. The samples were inserted in a thin aluminum envelope and placed into In-wire sealed Al cells.…”

“…The experimental INS spectra were recorded at 15 K using the TOSCA spectrometer at the ISIS spallation Neutron and Muon Source (Rutherford Appleton Laboratory, UK), 32,66,67 recorded by detectors both in forward and in backward directions for about 10 h per sample, then they were extracted and combined using Mantid software. 65 The neutron beam area at the sample position is 45 mm × 45 mm, ensuring that the whole sample enclosed within aluminum envelope was measured.…”

“…Only recently, INS has started to be applied to catalysts in the presence of adsorbates. Examples include the investigation of Pd- or Pt-based catalysts in the presence of hydrogen, − or the study of molecular mobility in zeolites …”