Moriau Leonard Jean, Hrnjić Armin, Pavlišič Andraž, Kamšek Ana Rebeka, Petek Urša, Ruiz-Zepeda Francisco, Šala Martin, Pavko Luka, Šelih Vid Simon, Bele Marjan, Jovanovič Primož, Gatalo Matija, Hodnik Nejc
Department of Materials Chemistry, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia.
Department of Catalysis and Chemical Reaction Engineering, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia.
iScience. 2021 Jan 28;24(2):102102. doi: 10.1016/j.isci.2021.102102. eCollection 2021 Feb 19.
Achieving highly active and stable oxygen reduction reaction performance at low platinum-group-metal loadings remains one of the grand challenges in the proton-exchange membrane fuel cells community. Currently, state-of-the-art electrocatalysts are high-surface-area-carbon-supported nanoalloys of platinum with different transition metals (Cu, Ni, Fe, and Co). Despite years of focused research, the established structure-property relationships are not able to explain and predict the electrochemical performance and behavior of the real nanoparticulate systems. In the first part of this work, we reveal the complexity of commercially available platinum-based electrocatalysts and their electrochemical behavior. In the second part, we introduce a bottom-up approach where atomically resolved properties, structural changes, and strain analysis are recorded as well as analyzed on an individual nanoparticle before and after electrochemical conditions (e.g. high current density). Our methodology offers a new level of understanding of structure-stability relationships of practically viable nanoparticulate systems.
在质子交换膜燃料电池领域，在低铂族金属负载量下实现高活性和稳定的氧还原反应性能仍然是重大挑战之一。目前，最先进的电催化剂是铂与不同过渡金属（铜、镍、铁和钴）的高比表面积碳载纳米合金。尽管经过多年的重点研究，但已确立的结构-性能关系仍无法解释和预测实际纳米颗粒系统的电化学性能和行为。在这项工作的第一部分，我们揭示了市售铂基电催化剂的复杂性及其电化学行为。在第二部分中，我们引入了一种自下而上的方法，记录并分析了在电化学条件（如高电流密度）前后单个纳米颗粒的原子分辨特性、结构变化和应变分析。我们的方法为实际可行的纳米颗粒系统的结构-稳定性关系提供了新的理解层面。
