Elucidating Molecular Interactions in Glycerol Adsorption at the Metal–Water Interface with Density Functional Theory

Abstract

Glycerol is an extremely versatile platform molecule for chemical and fuel production, as evidenced by successful demonstrations in electrochemical and thermochemical processes, where key catalytic chemistries occur at the solid–liquid interface. Despite the remarkable progress made in enriching the first-principles-based computational tool set to reveal and characterize solvent structures in the past decade, techniques for realistic and efficient molecular-level modeling to study aqueous-phase glycerol chemistry are still far from mature. Many aqueous-phase catalytic systems are deemed too complex for routine modeling because of their highly correlated structures at the heterogeneous solid–liquid interface. This invited feature article merges recent developments in quantum mechanical solvation models and oxygenated hydrocarbon conversion chemistry by revisiting the molecular interactions of adsorbed glycerol and its dehydrogenation intermediates at the water–metal interface. Explicit participation of water through the establishment of water–adsorbate, water–water, and water–metal interactions on Pt(111) was investigated using density functional theory. In periodic models, the adsorption favors networklike structures with adsorbates as nodal points linked by coadsorbed water molecules. We also showed that these adsorption patterns actually preserve the original bond-order-based scaling relationship framework established without the consideration of solvent. This behavior can be exploited to improve computational efficiency for future analysis of catalytic polyol conversions in the aqueous-phase environment.

Recent advances in the electrooxidation of biomass-based organic molecules for energy, chemicals and hydrogen production

“…77,218 Different theoretical approaches such as density functional theory (DFT) have been developed to examine the oxidation of C2-C3 alcohols, namely ethanol, [219][220][221][222] ethylene glycol 223 and glycerol. 35,176,[224][225][226][227][228][229][230][231] For the electrocatalysis community, the most extracted information is more valuable when a direct correction is made between DFT data wherein the Fermi level potential is commonly expressed in "eV" and those of the electrode/electrical potential traditionally articulated as "V vs SHE" or in the best case as "V vs RHE" (RHE being the universal electrochemical reference that does not depend on the pH of the electrolytes). The relationships of the potential E between the "vacuum scale" and "electrochemical scale" are given below by Eqs.…”

Elucidating energy scaling between atomic and molecular adsorbates in the presence of solvent

“…A few relationships applicable in the condensed phase have been reported. For example, Liu et al studied effects of water on adsorption energies of glycerol on Pd(111) facet 40 . They considered energies of individual interactions such as water–water, water‐Pd, and water‐glycerol in an additive fashion; adsorption energies of glycerol derivatives were estimated by counting the corresponding number of each type of bond formed by adsorbates.…”

Electrochemical Conversion of Biomass Derived Products into High-Value Chemicals

“…[27][28][29][30] Given the diverse possible orientation and adsorption modes of complex organic molecules, computational studies have been used to probe insight into interfacial phenomena. 31,32 Notably, for glycerol adsorption, calculated binding energies of reactant-surface molecular interactions revealed that C-H scissions, rather than O-H, gave rise to relatively more stable adsorbates, suggesting that first dehydrogenation step proceeded primarily at C atoms. 33 Besides, the stability of an adsorbate is inherently structure dependant as identified by other researchers.…”