Insight into the Interaction of Furfural with Metallic Surfaces in the Electrochemical Hydrogenation Process

Abstract

Electrocatalytic hydrogenation of furfural on metal surfaces has become an important research subject due to the potential of the reaction product 2‐methylfuran as a renewable energy resource. Identifying effective determinants in this reaction process requires a thorough investigation of the complex electrode‐electrolyte interactions, which considers a variety of the influential components. In this work, in operando electrochemical Raman Spectroscopy and Molecular Dynamics simulations were utilized to investigate different characteristics of the interface layer in the electrocatalytic hydrogenation of furfural. Hereby, the influence of applied potentials, electrode material, and electrolyte composition were investigated in detail. The studied parameters give an insight into furfural's binding situation, molecular orientation, and reaction mechanism.

Unraveling the reaction mechanisms for furfural electroreduction on copper

“…An ice-like water structure was used to represent the solvent structure in our model 26 , in order to approximate the endothermic solvent effect on the adsorption of larger molecules like furan compounds having a sizeable energetic penalty due to water displacement 27,28 . A slightly tilted orientation of furfural adsorption on Cu(111) was obtained shown in the inset of Figure 2a, in line with a recent molecular dynamics study 29 . The applied computational model is shown in Figure S1.…”

An experimental guide to in operando electrochemical Raman spectroscopy

“…Normalization can also aid in comparing relative intensities for spectra obtained at different potentials with various phenomena causing varying overall intensities [42]. Essential for an in-depth understanding of phenomena are supporting computational studies like density functional theory (DFT) or molecular dynamics (MD) simulations to estimate Raman shifts and correlating vibrations, orientations, and interactions of surface species [7,8,40,42,52].…”

“…In situ Raman and IR spectroscopy can fill this gap and allow investigating the molecular situation close to the surface, e.g., adsorbates, binding situations, molecular orientations, changes during a reaction, and intermediates [2][3][4]. These vibrational spectroscopic techniques are frequently employed for in situ/in operando investigations of catalytic processes [4][5][6][7]. Besides advantages like high temporal and spectral resolutions and sensitivities [3], the weak water signals make Raman spectroscopy an ideal tool for the in situ/in operando investigation of aqueous electrochemical reactions.…”

“…Besides advantages like high temporal and spectral resolutions and sensitivities [3], the weak water signals make Raman spectroscopy an ideal tool for the in situ/in operando investigation of aqueous electrochemical reactions. Several Raman spectroelectrochemical studies have improved the understanding of electroorganic synthesis [7][8][9][10][11], electrocatalysis [12,13], batteries [14], electrode interface behavior [15], and material science [16]. Also, molecule/surface interactions without applied potentials can be examined [17].…”

“…Fig 7. Possible optical setups using A a metallurgical objective, B a water immersion objective with a sapphire window, C a water immersion objective without a sapphire window, and D a water immersion objective without a sapphire window but a protective PVC foil.…”