The more the better: on the formation of single-phase high entropy alloy nanoparticles as catalysts for the oxygen reduction reaction
Rebecca K. Pittkowski, Christian M. Clausen, Qinyi Chen, Dragos Stoian, Wouter van Beek, Jan Bucher, Rahel L. Welten, Nicolas Schlegel, Jette K. Mathiesen, Tobias M. Nielsen, Jia Du, Asger W. Rosenkranz, Espen Drath Bøjesen, Jan Rossmeisl, Kirsten M. Ø. Jensen, Matthias Arenz
Abstract
X-ray powder diffraction with multi-edge X-ray absorption spectroscopy, we address the fundamental question of how single-phase HEA nanoparticles can form at low temperatures. It is demonstrated that the formation of HEA nanoparticles is governed by stochastic principles and the inhibition of precursor mobility during the formation process favors the formation of a single phase. The proposed formation principle is supported by simulations of the nanoparticle formation in a randomized process, rationalizing the experimentally found differences between two-element and multi-element metal precursor mixtures.