Thermodynamics and Kinetics of Ga Surface Segregation in Cu–Ga Nanoparticles across Composition and Particle Size
- 1Interdisciplinary Centre for Advanced Materials Simulation (ICAMS
- 2Ruhr University Bochum
- 3Institute of Materials Chemistry, TU Wien, Getreidemarkt 9, Vienna, Austria, 1060
Abstract
Cu–Ga nanoparticles are promising catalysts for thermochemical and electrochemical CO2 conversion, with their catalytic behavior determined by their surface composition. Here, we combine density functional theory (DFT) calculations with machine-learned interatomic potentials (MLIPs) to determine how Ga distributes within Cu–Ga nanoparticles depending on composition, size, and temperature. DFT results show that Ga forms a homogeneous solid solution within the bulk Cu lattice, whereas Ga-rich terminations are favored for surfaces. Molecular dynamics (MD) simulations at the nanosecond scale for particles (within 2 nm to 4.5 nm) and Ga contents up to 24 % reveal progressive Ga migration toward the surface. The extent and rate of this redistribution increase with temperature and Ga content, accompanied by increasing sphericity and structural disorder, until Ga surface enrichment saturates. The surface Ga fraction remains similar across particle sizes, whereas the fraction of total Ga at the surface decreases as particle size increases. A mean-field model captures this surface-to-interior partitioning, reproducing the surface compositions for the MD simulations at high temperatures. At lower temperatures and for larger nanoparticles, Ga redistribution is kinetically limited within the timescale of the simulations. Calculated apparent diffusion barriers for Cu and Ga obtained at high temperatures support this interpretation.
Related
- Adsorption of crystal violet and malachite green onto dibarium magnesium orthoborate (Ba₂Mg(BO₃)₂): equilibrium, kinetics and thermodynamics.
- Efficient removal of regorafenib from aqueous solutions using KOH-activated hazelnut husk-derived activated carbon: adsorption mechanism, kinetics, isotherms and thermodynamics
- Thermodynamics, Adsorption Kinetics, and Interfacial Partitioning of Tetracycline Antibiotics on Biodegradable Polyester versus Polyethylene Microplastics
- Online Measurements Reveal Contrasting Particle-Bound Reactive Oxygen Species and Chemical Composition in Emissions from Six Residential Solid Fuels
- Summertime Aerosol Composition in Southern Greenlandic Fjords: Impacts of Sources and New Particle Formation Events.
BibTeX
@misc{eseroglou2026thermodynamics,
title = {{Thermodynamics and Kinetics of Ga Surface Segregation in Cu–Ga Nanoparticles across Composition and Particle Size}},
author = {Christoforos Eseroglou and Linus C. Erhard and Aleix Comas-Vives},
howpublished = {ChemRxiv},
year = {2026},
month = oct,
doi = {10.26434/chemrxiv.15010807/v1},
url = {https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010807/v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - Thermodynamics and Kinetics of Ga Surface Segregation in Cu–Ga Nanoparticles across Composition and Particle Size
AU - Christoforos Eseroglou
AU - Linus C. Erhard
AU - Aleix Comas-Vives
PY - 2026
DA - 2026/10/21
PB - ChemRxiv
DO - 10.26434/chemrxiv.15010807/v1
UR - https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010807/v1
AB - Cu–Ga nanoparticles are promising catalysts for thermochemical and electrochemical CO2 conversion, with their catalytic behavior determined by their surface composition. Here, we combine density functional theory (DFT) calculations with machine-learned interatomic potentials (MLIPs) to determine how Ga distributes within Cu–Ga nanoparticles depending on composition, size, and temperature. DFT results show that Ga forms a homogeneous solid solution within the bulk Cu lattice, whereas Ga-rich terminations are favored for surfaces. Molecular dynamics (MD) simulations at the nanosecond scale for particles (within 2 nm to 4.5 nm) and Ga contents up to 24 % reveal progressive Ga migration toward the surface. The extent and rate of this redistribution increase with temperature and Ga content, accompanied by increasing sphericity and structural disorder, until Ga surface enrichment saturates. The surface Ga fraction remains similar across particle sizes, whereas the fraction of total Ga at the surface decreases as particle size increases. A mean-field model captures this surface-to-interior partitioning, reproducing the surface compositions for the MD simulations at high temperatures. At lower temperatures and for larger nanoparticles, Ga redistribution is kinetically limited within the timescale of the simulations. Calculated apparent diffusion barriers for Cu and Ga obtained at high temperatures support this interpretation.
ER -