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New mechanistic insight into electronically excited CO-NiO(100): a quantum dynamical analysis
Imed Mehdaoui1, Thorsten Klüner
1Institut für Reine und Angewandte Chemie, Theoretische Chemie and the Center of Interface Science (CIS), Carl von Ossietzky Universität Oldenburg, Oldenburg, Germany.
Physical Chemistry Chemical Physics : PCCP
|July 31, 2008
Summary
Ultraviolet laser pulses drive carbon monoxide (CO) desorption from nickel oxide (NiO) surfaces. Quantum simulations reveal a C-Ni bond formation is key to this photodesorption mechanism.
Area of Science:
- Surface science
- Physical chemistry
- Quantum dynamics
Background:
- Experimental studies on CO desorption from NiO(100) after UV laser irradiation lacked mechanistic insight.
- Previous theoretical work suggested a 5sigma --> 2pi* transition in CO as the excitation step, despite apparent energy mismatches.
Purpose of the Study:
- To elucidate the excitation and desorption mechanism of CO from NiO(100) following UV laser pulse.
- To investigate the role of electronically excited states and dynamical processes in photodesorption.
Main Methods:
- Utilized three-dimensional (3D) ab initio potential energy surfaces.
- Performed quantum dynamical wave packet simulations to analyze post-excitation dynamics.
Main Results:
- Corroborated the proposed excitation mechanism involving a 5sigma --> 2pi* transition.
- Identified the formation of a C-Ni bond as the critical driving force for photodesorption.
Conclusions:
- The study provides crucial insights into the electronic states and dynamics governing CO photodesorption from NiO(100).
- Confirms the C-Ni bond formation as the primary mechanism initiating photodesorption.
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