Effect of graphene support on large Pt nanoparticles
L G Verga1, J Aarons1, M Sarwar2
1Department of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, UK. c.skylaris@soton.ac.uk.
Physical Chemistry Chemical Physics : PCCP
|November 24, 2016
Summary
Three-dimensional platinum (Pt) clusters are more stable on graphene supports than 2D clusters, with stability increasing with size. Dispersion interactions are crucial for accurately modeling larger nanoparticles in catalyst design.
Area of Science:
- Materials Science
- Physical Chemistry
- Computational Chemistry
Background:
- Catalysts are crucial for industrial processes, often utilizing supported nanoparticles to enhance surface area and reduce costs.
- Understanding nanoparticle-support interactions is key to designing efficient and cost-effective catalytic materials.
Purpose of the Study:
- To investigate the stability and electronic properties of platinum (Pt) clusters on graphene supports using large-scale DFT calculations.
- To quantify the influence of nanoparticle size and dimensionality on their interaction with graphene.
Main Methods:
- Employed large-scale Density Functional Theory (DFT) calculations to simulate Pt clusters (up to 309 atoms) on graphene supports (up to 880 atoms).
- Computed adsorption, cohesion, and formation energies, incorporating dispersion interactions using semi-empirical corrections and vdW functionals.
- Analyzed structural changes, charge redistribution, and electronic properties at the Pt-graphene interface.
Main Results:
- Three-dimensional Pt clusters exhibit greater stability on graphene compared to two-dimensional clusters, with this difference amplifying as system size increases.
- Dispersion interactions become more significant with increasing nanoparticle size, proving essential for accurate modeling of larger systems.
- Observed charge transfer from Pt clusters to the graphene support, accompanied by Pt-Pt bond expansion/contraction correlated with adsorption energy.
Conclusions:
- The stability and electronic structure of Pt nanoparticles are significantly influenced by the graphene support, necessitating its inclusion in computational models.
- These findings provide quantitative insights into size and support effects for catalytically relevant nanoparticle sizes, crucial for advanced catalyst design.
