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E u r o s c i c o n C o n f e r e n c e o n
Physical Chemistry and
Analytical Separation Techniques
October 08-09 , 2018
Amsterdam, Nether l ands
Journal of Organic & Inorganic Chemistry
ISSN: 2472-1123
Physical Chemistry and Analytical Separation Techniques 2018
Formany processes in chemistry and in catalysis, diffusion plays an important
role. Specifically, for forming nanoparticles during the preparation of solid
catalysts and for sintering during their use, controlling the diffusion of metal
atoms or ions is the key. The diffusion of metal atoms over the surface of
metallic nanoparticles, pristine support surfaces, and hydroxylated support
surfaces has been studied before by others. However, the diffusion of metal
ions over (hydroxylated) support surfaces has not yet received any attention.
Nonetheless, especially during catalyst preparation it is ions that diffuse, so the
mobility of ions needs to be studied as well. For the diffusion of ions, everything
revolves around the behaviour of counter-charges: displacements of charged
ions without any charge compensation would lead to charge separation
resulting in high diffusion barriers. However, co-diffusion of counter-ions is
not trivial, since these are often incorporated in the hydroxylation layer and are
strongly bound by hydrogen bonds. For the co-diffusion of OH− ions, we have
observed that there are two possiblemechanisms: adjustments of the hydrogen
bond network to allow OH− co-diffusion, or counter-diffusion of protons, or a
combination of these two mechanisms. Using density functional theory (DFT),
we studied the diffusion of Cu2+ and Cu+ ions over the surface of γ-alumina
at varied hydration states. Apart from setting up a methodology to overcome
the challenges of sampling, the many possible adjustments of the hydrogen
bond network, we have found interesting trends in the balance between the
two possible charge-compensation mechanisms depending on the hydration
state of the surface and the charge of the metal ion. We anticipate that many
of our conclusions can be translated to other metal ions and types of supports
as well, based on the hydrophilicity of the support and the net charge of the
metal ion involved
Biography
Manuel J Louwerse has completed his PhD from the Free
University Amsterdam. He has worked as Researcher at
Organon and TNO and had several postdoctoral positions at the
University of Amsterdam and Utrecht University. His research
focusses on the Application of Molecular Modelling in several
fields of Chemistry. He has published more than 15 papers in
reputed journals.
Modelling ion diffusion over hydroxylated support surfaces
Manuel J Louwerse
Debye Institute for Nanomaterials Science-Utrecht University, The Netherlands
Manuel J Louwerse, J Org Inorg Chem 2018 Volume: 4
DOI: 10.21767/2472-1123-C6-017