Events

04 July

In-situ transmission electron microscopy of multinary nanoparticles for energy applications

Monday 04 July 2022, 11:30am

ICN2 Seminar Room, Campus UAB

By Dra. Alba Garzón-Manjón, Project leader at Max-Planck-Institut für Eisenforschung GmbH, Düsseldorf, Germany

Abstract: Complex solid solution nanoparticles (CSSNPs) are promising candidates for energy applications [1]. Direct current sputtering (DCS) from an alloy target (Cr-Mn-Fe-Co-Ni) is a promising route to synthesize CSSNPs into ionic liquids [2]. Due to their low vapor pressure, ionic liquids (salts with a melting point < 100°C) can be used as liquid substrates in the sputtering processes. In addition, the ionic liquid itself can act as an electronic and steric stabilizer preventing particle growth and aggregation, and hence leading to the formation of nanometer-sized particles with unique structures and compositions.

We developed pathways to produce CCSNPs with different sizes (from 1.3 ± 0.1 nm up to 2.6 ± 0.3 nm), crystallinity (amorphous, face-centered cubic or body-centered cubic) and composition into a library of ionic liquids (Figure 1). We analysed the intrinsic electrocatalytic properties of the different CSSNPs towards the oxygen reduction reaction in alkaline media and found some exceptionally high activity, overperforming Pt NPs [3)

Electron microscopy techniques were the key to understand the outstanding intrinsic electrocatalytic behaviour of the CSSNPs and to determine the structure-activity correlations needed for targeted catalyst design. Using advanced microscopy techniques, such as aberration-corrected (scanning) transmission electron microscopy and energy dispersive X-ray spectroscopy the growth mechanism, crystallinity, defects and chemical composition of the nanoparticles were identified. In-situ studies focussed on the Ostwald ripening at the atomic scale and examine how the different diffusion constants of the various atomic species are affecting the growth [4]

  • [1]  Löffler, T et al.; Advanced Energy Materials. 2019, 8(34), 1802269.
  • [2]  Garzón Manjón, A et al.; Nanomaterials. 2018, 8(11), 903.
  • [3]  Garzón Manjón, A et al.; Nanoscale. 2020, 12, 23570-23577.
  • [4]  Garzón Manjón, A et al. MRS Bulletin. 2021 (accepted).

This work was funded by the German Science Foundation (DFG) via the project SCHE634/21 1 and LU1175/23-1. We thank the Creative Studio Lena Heel for the graphical representation in Figure 1. 

Hosted by Prof. Jordi Arbiol, Advanced Electron Nanoscopy Group Leader at ICN2.