Relativistic Effects in Platinum Nanocluster Catalysis: A Statistical Ensemble-Based Analysis
Akhil S Nair1, Anakuthil Anoop2, Rajeev Ahuja3,4
1Department of Chemistry, Indian Institute of Technology Indore, Simrol, Indore, 453552, India.
The Journal of Physical Chemistry. A
|February 21, 2022
Summary
Relativistic effects, specifically spin-orbit coupling (SOC), significantly influence the catalytic activity of platinum nanoclusters in the oxygen reduction reaction (ORR). SOC impacts structural stability and reaction pathways, crucial for understanding nanocluster catalysis.
Area of Science:
- Computational chemistry
- Materials science
- Catalysis
Background:
- Nanoclusters are vital catalysts, with properties influenced by relativistic effects.
- Understanding these effects is key to optimizing nanocluster catalytic performance.
Purpose of the Study:
- To investigate the role of relativistic effects, particularly spin-orbit coupling (SOC), on the oxygen reduction reaction (ORR) activity of a Pt7 nanocluster.
- To delineate how SOC influences structural stability, adsorption energetics, and reaction pathways.
Main Methods:
- Global optimization analysis to determine cluster isomer stability.
- Ab initio atomistic thermodynamics to predict phase diagrams under realistic conditions.
- Statistical ensemble-based approach to assess activity contributions.
Main Results:
- Spin-orbit coupling (SOC) critically regulates the stability of Pt7 nanocluster isomers.
- SOC alters adsorption energetics and induces different structural changes upon adsorption.
- While overall activity is similar, SOC crucially affects the rate-determining step and transition states.
Conclusions:
- Relativistic effects, including SOC, are essential for accurately modeling nanocluster catalysis.
- SOC significantly impacts the detailed mechanisms and energetics of elementary reaction steps in ORR.
- The study highlights the importance of considering relativistic effects for designing efficient nanocluster catalysts.
