(544du) The Effect of Solvents on the Decomposition of Acetic Acid Using Density Functional Theory and Ambient Pressure XPS

Seekins, S., Oregon State University
Chukwu, K., Oregon State University
Arnadottir, L., Oregon State University
Mechanistic understanding of catalytic reactions is at the heart of the development of new processes in the chemical industries. Many of these catalytic reactions occur in ambient conditions, high pressures, or in the presence of a liquid solvent. Most of our atomistic understanding of these catalytic reactions comes from ultrahigh vacuum research studies. Here we start bridging this gap between ultrahigh vacuum and industrial conditions by combining near ambient pressure x-ray photoelectron spectroscopy (NAP-XPS) and density functional theory (DFT) to investigate the effect of various solvents on the decomposition of acetic acid and ethanol on the Pd(111) surface. DFT is used to calculate binding energies, reaction energies, and transition states, both in vacuum conditions and in the presence of solvents. The solvent calculations are performed either through an implicit solvent calculation (VASPsol), or by explicitly adding individual water molecules or a water bilayer to each elementary step in the reaction pathway. NAP-XPS studies of acetic acid on Pd(111) at different water partial pressures are used to confirm theoretical results by the analysis of C1s binding states and quantification of elemental composition. These studies will help us better understand the role of different solvents in catalytic processes.