- 19.12.2018 -
S3 Seminar Maria Chiara Spadaro
Date and Time: Wednesday December 19, 2018 - 11.30
Venue: S3 Seminar Room, Third Floor, Physics Building, FIM Department
Speaker: Maria Chiara Spadaro
Group of Advanced Electron Nanoscopy, Institut Catala de
Nanosciencia i Nanotecnologia (Barcelona, Spain) and Nanomaterials Lab, College of Engineering, Swansea University (Swansea, UK).
Title: Recent advances on the preparation of ultra-precise catalysts
Abstract:Cluster Beam Deposition (CBD) is one of the most promising techniques for the production of supported nanoparticle assemblies. It offers the possibility to grow and stabilize single clusters without any solvent and/or effluent, as well as the deposition of monodispersed clusters with desired size and shape, and to combine different metals. These peculiarities ensure the possibility to deposit stable catalyst assemblies with desired characteristics and specific aims, i.e. reducing the use of critical metals [1], such as platinum, by alloying them with other less-precious materials.
Pt-based bimetallic clusters have been produced using the Multiple Ions Cluster Source (MICS) recently developed by Dr Yves Huttel [2]. Here the single magnetron, that is present in conventional magnetron-based cluster source, is replaced with three independent magnetrons, allowing the production of a wide range of alloy clusters, by controlling both the cluster’s composition and atomic structure simply playing with the mutual magnetrons position and sputtering rates.
The obtained activity-structure dependence can be exploited for the production of grams of catalyst using the new source developed by Prof Richard Palmer which enables the scale-up of ultraprecise cluster production: the Matrix Assembly Cluster Source (MACS) [3]. Here the cluster formation/deposition is realized in two steps:
(1) the gas-metal matrix formation and (2) the matrix sputtering using an Ar+ ion beam.
All the above mentioned studies were completed with detailed electron microscopy investigation,
for structure and composition evaluation.
References:
[1] http://ec.europa.eu/growth/sectors/raw-materials/specific-interest/critical_it
[2] Martinez L. et al, Nanoscale, 9, 6463, 2017
[3] Palmer R.E. et al, Rev. Sci. Instrum. 87, 046103 (2016)
Acknowledgments:
I acknowledge all the people involved in this work, especially Prof Richard Palmer and Prof Jordi
Arbiol. This work is financially supported by the European Horizon 2020 project “CritCat” under
the grant agreement number 686053, and the Marie Curie COFUND Action PROBIST under the grant agreement number 754510
Host: Paola Luches paola.luches@nano.cnr.it