Theoretical Studies of Surface Reaction Dynamics

With support from the Chemical Structure, Dynamics, and Mechanisms-A (CSDM-A) and the Chemical Theory, Models, and Computational Methods (CTMC) Programs in the Division of Chemistry, Professor Hua Guo of the University of New Mexico and his research team aim to advance the fundamental understanding of dynamics for atomic and molecular interactions with metal and semiconductor surfaces using computational methods. Professor Guo and his research group will focus on the computational characterization of elementary processes such as adsorption, desorption, scattering, diffusion, and reaction to provide systematic and comprehensive insights into surface reaction dynamics. The knowledge gained from these fundamental studies has the potential to help establish key principles and predictive models for interfacial phenomena thus allowing for better elucidation of important chemical and physical processes at surfaces ranging from corrosion, device fabrication, and heterogeneous catalysis. The students engaged in this work will gain valuable experience in computational research, which will be enhanced through collaborations with experimentalists. An accurate description of energy dissipation in surface processes via both adiabatic and nonadiabatic pathways is sought using density functional theory (DFT), machine learning, as well as classical, semi-classical, and quantum mechanical methods. DFT will be used for understanding the electronic structure of interfacial systems; machine learning will be used for representing high-dimensional potential energy surfaces and other properties, while a combination of classical, semi-classical, and quantum mechanical methods will also be used for simulating nuclear dynamics. Because adiabatic and nonadiabatic pathways are altered by phonons and electron-hole pairs at surfaces, Professor Guo and his group will investigate how energy flow and bond forming/breaking events vary at metal and semiconductor interfaces. This includes investigations of energy dissipation of hot adsorbates, atomic scattering from semiconductor surfaces, vibrational excitation effects in Eley-Rideal reactions on metals, post-transition state dynamics in decomposition/desorption reactions from metal surfaces, and quantum effects in surface reaction rates on metals. Specific objectives include a better understanding of non-Born-Oppenheimer effects, nuclear quantum effects, and mode specificity in reactivity and energy disposal. Collaboration with experimentalists groups will help guide the computational studies so that the complex interplay of energy transfer and chemical transformation on solid surfaces can be better understood. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.