(363c) Computational Insights into Solvent Effects on Catalysis and Biomolecules

computational chemistry in catalysis and biological process

Solvent effects have a wide range of applications on catalysis and biological processes. In heterogeneous catalysis, solvents can interact with catalyst surface to impact their catalytic activity and selectivity. These effects are more profound in confined spaces, such as the micropores of zeolites, which are significantly dependent on the density and composition of solvents. In addition, the hydrophilicity of pores and polarity of solvents have also been suggested to affect the catalytic performance of zeolites.

To understand the solvent effects on zeolite catalysts at the molecular level, in PhD program, I utilize computational approaches using LAMMPS and CP2K software. I explore solvation thermodynamics of oxygenates in hydrophilic and hydrophobic pores of Ti-FAU zeolite under methanol/water mixture. Multiscale sampling (MSS) methods, combing molecular dynamics and density functional theory, are employed to calculate free energy and entropy of oxygenates under solvation. Both solvents and adsorbates contribute to variations in solvation free energy. My work also reveals that water densities around binding sites are higher than those of methanol, which is more profound in hydrophilic pores. We further examine the interaction of solvent molecules with reactive species and pores of the zeolites. The results indicate that the hydrophobicity of zeolite pores could influence the stability of reactive species in the presence of solvents.

In MS program, I studied binding affinity of biomolecules with metal ions in aqueous phase via computational techniques as the metal uptake of biomolecules holds great potentials in wastewater treatment and disease treatment. In this study, I focused on the Siderophore type biomolecules, such as enterobactin (Ent), which can chelate with metal ions due to their high binding affinities. I determined the binding strength of Ent with bivalent and trivalent metal ions such as Cu, Ni, Zn, Co and Fe via DFT using ORCA programs. The solvation energy was calculated using implicit solvation model CPCM (conductor-like polarizable continuum model). My study suggested that the trend of binding strength of Ent with metal is strongly influenced by solvation effects.