In Situ Strain Evolution on Pt Nanoparticles during Hydrogen Peroxide Decomposition

Area of Science:

• Materials Science
• Surface Chemistry
• Catalysis

Background:

• Understanding structural changes during catalysis is vital for mechanism elucidation and efficiency optimization.
• While surface energy is well-studied, catalyst lattice deformation during reactions remains less understood.

Purpose of the Study:

• To investigate catalyst lattice deformation induced by catalytic processes.
• To study strain in individual platinum nanoparticles (Pt NPs) during in situ oxidation and reduction reactions.

Main Methods:

• Utilized Bragg coherent diffraction imaging to analyze strain in individual Pt NPs.
• Performed in situ oxidation and reduction reactions, specifically using hydrogen peroxide (H2O2).
• Employed density functional theory (DFT) calculations to interpret observed strain patterns.

Main Results:

• Observed alternating strain distribution in Pt NPs upon exposure to H2O2 at the (111) Bragg reflection.
• Noted insignificant strain changes at the (200) reflection under the same conditions.
• Rationalized anisotropic lattice strain using DFT, linking it to H2O2 adsorption and decomposition.

Conclusions:

• The study provides critical insights into anisotropic lattice strain in Pt NPs during catalytic reactions.
• Highlights the importance of considering lattice deformation for understanding catalyst behavior.
• Offers a deeper understanding of the activity-structure relationship in Pt-based catalytic systems.