In-situ 3D Imaging of Catalysis Induced Strain in Gold Nanoparticles

TL;DR

This study uses advanced 3D imaging to observe how strain in gold nanoparticles affects their catalytic activity during reactions, combining experimental and simulation approaches to deepen understanding of nanocatalyst behavior.

Contribution

It introduces a novel in-situ 3D imaging technique for single nanoparticles during catalysis and links local strain to catalytic activity through combined experimental and simulation methods.

Findings

Local strains are generated by hydroxyl chemisorption.

Strain influences catalytic activity in gold nanoparticles.

Simulations confirm experimental strain measurements.

Abstract

Multi-electron transfer processes, such as hydrogen and oxygen evolution reactions, are crucially important in energy and biological science but require favorable catalysts to achieve fast kinetics. Nanostructuring catalysts can dramatically improve their properties, which can be difficult to understand due to strain and size dependent thermodynamics, the influence of defects, and substrate dependent activities. Here, we report 3D imaging of single gold nanoparticles during catalysis of ascorbic acid decomposition using Bragg coherent diffractive imaging (BCDI) as a route to eliminate ensemble effects while elucidating the strain-activity connection. Local strains were measured in single nanoparticles and modeled using reactive molecular dynamics (RMD) simulations and finite element analysis (FEA) simulations. RMD reveals a new chemical pathway for local strain generation in the gold lattice: chemisorption of hydroxyl ions. FEA reveals that the RMD results are transferable to the larger nanocrystal sizes studied in the experiment. Our study reveals the strain-activity connection and opens a powerful new avenue for joint theoretical and experimental studies of multi-electron transfer processes catalyzed by nanocrystals.