Laser‐induced desorption of small molecules from oxide surfaces: A first‐principles study

Abstract

Recent efforts in the theoretical simulation of laser-induced desorption of small molecules from surfaces are summarized. As a representative example, photodesorption of CO molecules from a Cr2O3(0001) surface is investigated since detailed quantum state resolved experimental results are available for this system. In particular, vectorial properties such as the alignment of the desorbing species are considered. Furthermore, the influence of surface temperature as a control parameter is investigated, and lateral velocity distributions are calculated and compared with experimental results. All simulations presented in the present study are based on ab initio potential energy surfaces (PESs) for the electronic ground state as well as electronically excited states involved in the desorption process. These PESs provide the prerequisite for extensive high-dimensional quantum mechanical simulations of the dynamics of nuclear motion based on a stochastic wave packet scheme. These wave packet calculations allow for a detailed microscopic understanding of experimental results and provide a perspective for future experiments

Theoretical Approaches to Excited-State-Related Phenomena in Oxide Surfaces

“…In a rather long and complete series of papers, Klüner et al have studied quite in detail the photodesorption of CO and NO from NiO(100), − CO from Cr 2 O 3 (001), − including the analysis of the angular momentum of desorbed molecules and lateral velocity distribution, and, more recently, CO on TiO 2 (110) . These works are all based on modeling the oxide surface by an embedded cluster model and obtaining suitable approximations for the ground state and relevant excited states, initially, from CASSCF wave functions and, later, including dynamical correlation effects through the second-order CASPT2 approach.…”

Quantum Dynamical Approach to Ultrafast Molecular Desorption from Surfaces

“…This is unsatisfactory, in particular for molecules. Here, in a series of papers, Klüner and co-workers fill a gap by considering multidimensional quantum dynamics of diatomic molecules desorbing from transition metal oxide surfaces . The goal is to treat the problem as high-dimensional as possible.…”

Thermal and photochemical reactions of NO2 on chromium(iii) oxide surfaces at atmospheric pressure

“…For example, adsorbed NO and CO undergo photo-induced desorption from Cr 2 O 3 surfaces. [88][89][90][91][92][93][94] On the other hand, CH 3 Br on a-Cr 2 O 3 photodissociates at l r 385 nm, while only desorption occurs at longer wavelengths. 87 A theoretical study suggests that the hole mobility in a-Cr 2 O 3 is three orders of magnitude greater than that of electrons.…”