Tracking the 3D atomic structures during thermal treatment and catalytic activity of individual Pt nanoparticles

To acquire a crystal-clear structure-performance relation for heterogeneous nanocatalysts, precise tracking of the structural evolution from the precursor to final product in the real time and space domain is important but also extremely challenging. In archetype preparation, thermal treatment is a crucial step for activation. Especially, for colloidally synthesized nanoparticles, the ligand detachment process to expose surfaces is completed with thermal treatment. Here, we track the three-dimensional atomic structural change of ligand-protected platinum nanoparticles under ligand detachment and thermal annealing processes. The structural transformation with time is shown by experimental decoupling and tracking of each atomic coordinate through molecular dynamics simulations with machine-learning potentials. Acquisition of structural data is integrated with a computational catalysis framework to identify a structure-activity correlation in the CO oxidation reaction. We find that colloidally synthesized platinum nanoparticles create unique atomic tensile strain and that varying the particle size tunes the ensemble effect of active sites.