(630e) Energy Scaling Approach for the Rational Design of Catalysts for Selective Hydrogenation of ?,?-Unsaturated Aldehydes in the Condensed Phase

Energy correlations between energies of adsorbed complex molecules and thermochemical descriptors can save computational cost when screening catalysts by minimizing the amount of required explicit calculation (using, e.g., DFT). Relationships for various adsorbates have been established and utilized to identify desired catalysts in mainly gas-phase reactions. However, condensed phase heterogeneous catalytic reactions are attracting increased attention for, e.g., transformations of biomass which have higher boiling points and larger molecular weight reactants. Similar to the difficulty of characterizations in a liquid medium, the condensed phase is difficult to investigate theoretically due to the high computational cost for dealing with numerous solvent molecules, resulting in an unclear path to screening studies.

In our previous study, we confirmed linear scaling relations between the energies of adsorbed species in highly disordered water configurations. We additionally presented scaling relations for relevant species of selective hydrogenation of α,β-unsaturated aldehydes in the gas phase and in the presence of one water molecule. In this talk, we will bridge the gap to explicitly explore the energy scaling properties of crotonaldehyde and cinnamaldehyde hydrogenations on transition metals in condensed phase environments, toward the goal of generating selectivity plots for practical catalyst design. Using a combination of molecular dynamics (MD), ab initio molecular dynamics (AIMD), we sample a broad configurational space of solvent-adsorbate-surface interactions and sample their energetics to determine reaction energetics in the condensed phase. We focus on comparing the reaction enthalpies of two competitive pathways, C=C bond and C=O bond hydrogenation, plotting these as a function of descriptors for crotonaldehyde (CAL) and cinnamaldehyde hydrogenation toward the goal of maximizing alcohol formation. Based on distinct experimental results with various solvents, we test water, butanol, and toluene as solvents in the target reactions.