Catalyst surface analysed at atomic resolution

Date:
January 10, 2022
Source:
Ruhr-University Bochum
Summary:
A research team has visualized the three-dimensional structure of
the surface of catalyst nanoparticles at atomic resolution. This
structure plays a decisive role in the activity and stability
of the particles. The detailed insights were achieved with a
combination of atom probe tomography, spectroscopy and electron
microscopy. Nanoparticle catalysts can be used, for example, in
the production of hydrogen for the chemical industry. To optimize
the performance of future catalysts, it is essential to understand
how it is affected by the three-dimensional structure.



FULL STORY ========================================================================== Researchers from the Ruhr-Universita"t Bochum, the University of
Duisburg-Essen and the Max Planck Institute for Chemical Energy
Conversion in Mu"lheim an der Ruhr cooperated on the project as part of
the Collaborative Research Centre "Heterogeneous oxidation catalysis in
the liquid phase."

==========================================================================
At RUB, a team headed by Weikai Xiang and Professor Tong Li from
Atomic-scale Characterisation worked together with the Chair of Electrochemistry and Nanoscale Materials and the Chair of Industrial
Chemistry. Institutes in Shanghai, China, and Didcot, UK, were also
involved. The team presents their findings in the journal Nature Communications, published online on 10 January 2022.

Particles observed during the catalysis process The researchers studied
two different types of nanoparticles made of cobalt iron oxide that were
around ten nanometres. They analysed the particles during the catalysis
of the so-called oxygen evolution reaction. This is a half reaction that
occurs during water splitting for hydrogen production: hydrogen can be
obtained by splitting water using electrical energy; hydrogen and oxygen
are produced in the process. The bottleneck in the development of more efficient production processes is the partial reaction in which oxygen
is formed, i.e. the oxygen evolution reaction. This reaction changes
the catalyst surface that becomes inactive over time. The structural
and compositional changes on the surface play a decisive role in the
activity and stability of the electrocatalysts.

For small nanoparticles with a size around ten nanometres, achieving
detailed information about what happens on the catalyst surface during
the reaction remains a challenge. Using atom probe tomography, the group successfully visualised the distribution of the different types of atoms
in the cobalt iron oxide catalysts in three dimensions. By combining
it with other methods, they showed how the structure and composition of
the surface changed during the catalysis process -- and how this change affected the catalytic performance.

"Atom probe tomography has enormous potential to provide atomic insights
into the compositional changes on the surface of catalyst nanoparticles
during important catalytic reactions such as oxygen evolution reaction
for hydrogen production or CO2 reduction," concludes Tong Li.

========================================================================== Story Source: Materials provided by Ruhr-University_Bochum. Original
written by Julia Weiler.

Note: Content may be edited for style and length.


========================================================================== Journal Reference:
1. Weikai Xiang, Nating Yang, Xiaopeng Li, Julia Linnemann, Ulrich
Hagemann,
Olaf Ruediger, Markus Heidelmann, Tobias Falk, Matteo Aramini,
Serena DeBeer, Martin Muhler, Kristina Tschulik, Tong Li. 3D
atomic-scale imaging of mixed Co-Fe spinel oxide nanoparticles
during oxygen evolution reaction. Nature Communications, 2022; 13
(1) DOI: 10.1038/s41467-021- 27788-2 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2022/01/220110103227.htm
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