Influence of the Electrode-Electrolyte Interface on the Product Distribution of the HMF Electroreduction

The electrochemical reduction of 5-hydroxymethylfurfural (HMF), a biomass-based platform chemical, is a promising route towards the defossilization of the transportation sector. It yields fuels, such as 2,5-dimethylfuran (DMF), and fuel precursors, such as 2,5-dihydroxymethylfuran (DHMF) and 5,5’-bis(hydroxylmethyl)hydrofuroin (BHH), while requiring only renewable resources. In order to control the selectivity of this reaction and to optimize the yield of the desired target compound, it is important to understand the reaction mechanisms towards the individual products and the influence of various system parameters. We utilize two complementary methods, namely electrochemical real-time mass spectrometry (EC-RTMS) and quantitative batch electrolysis in a flow reactor, to obtain further insights into the electrochemical HMF reduction mechanisms and the interplay between the electrode and electrolyte. While EC-RTMS is a fast screening technique, which allows for the analysis of transient processes, the batch electrolysis in the flow reactor enables product quantification by high-performance liquid chromatography (HPLC) and gas chromatography (GC) and the calculation of reaction selectivities and faradaic efficiencies. With these techniques, we were able to investigate the influence of various system parameters, such as the electrode material, the applied potential and the composition of the electrolyte, on the product distribution and propose reaction mechanisms towards the individual products.[1] References [1] R. Kloth, D. V. Vasilyev, K. J. J. Mayrhofer, I. Katsounaros, Electroreductive 5-Hydroxymethylfurfural Dimerization on Carbon Electrodes ChemSusChem 2021, 14, 5245. Figure 1