Theoretical description of femtosecond laser-induced desorption dynamics using ab initio and machine learning methods: pure CO and mixed CO+O adlayers on Pd(111)

PhD Program

Speaker

Alfredo Serrano Jiménez

When

2025/03/28
10:30

Place

CFM Auditorium, Donostia / San Sebastián

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PhD Thesis defense by Alfredo Serrano Jiménez

Supervisors: Maite Alducin Ochoa and Joseba Iñaki Juaristi Oliden.

In this thesis, femtosecond laser-induced desorption of CO from Pd(111) at various coverages, as well as photodesorption and photooxidation of CO coadsorbed with oxygen (0.25 ML O + 0.50 ML CO/Pd(111)), are examined. Using ab initio molecular dynamics with electronic friction (AIMDEF) and neural network-based potential energy surfaces (NN PESs), the research addresses the interplay of electronic and phononic excitations. Multiple factors—including coverage, laser fluence, and isotope effects—are investigated. Simulations underscore the cooperation of electrons and phonons in aforementioned processes, and reveal their relative roles on desorption. Oxygen coadsorption modifies interadsorbate energy exchange, enabling the formation of CO₂. By incorporating NN PESs, computational efficiency is significantly increased, allowing long-timescale dynamics and more comprehensive statistical analyses. These findings provide a deeper understanding of CO desorption and oxidation on Pd(111), offering insights for catalytic system design and advancing theoretical modeling and potential applications in surface chemistry. Future studies can refine these methodologies and insights.