Reaction-driven restructuring of Pt-Rh nanoparticles: Bragg coherent diffraction imaging (BCDI) during gas-surface reactions

Platinum group metals and their metal alloys are among the most important catalysts for organic and electrochemical reactions [1,2]. For this reason, the structure-activity relationships of the platinum alloy nanoparticles have been a focus of extensive studies. Some studies [3,4] even suggested that the core-shell compositions of nanoparticles can dynamically change depending on gas reaction environments. Until now, however, there was no direct evidence for the dynamic restructures because there has been no in-situ experimental technique that can directly image the internal alloy compositions. The situation changed recently because new coherent X-ray imaging techniques emerged and advanced rapidly. The internal composition of Pt-Rh nanoparticles was, therefore, analyzed in situ under different gas environments, which unveiled dynamic composition changes near the particle surfaces [5].



1. G. A. Somorjai and Y. Li, Introduction to surface chemistry and catalysis (Wiley, 2010).

2. G. Ertl, Reactions at Solid Surfaces (Wiley, 2009).

3. F. Tao et al., Science 322, 932-935 (2008).

4. P. Müller et al., Phys. Chem. Chem. Phys. 16, 13866 (2014).

5. T. Kawaguchi et al., Phys. Rev. Lett. 123, 246001 (2019).



Supported by the DOE, BES, Materials Sciences and Engineering Division, use of the APS by DOE BES Scientific User Facilities Division, under contract no. DE-AC02-06CH11357, DESY by the EU-H2020 under grant no. 654360 NFFA-Europe, and Tohoku University by JSPS KAKENHI of 21H01646 and 22KK0068.