Carbon-Supported Ag Nanoparticle Aerogel for Electrocatalytic Hydrogenation of 5-(Hydroxymethyl)furfural to 2,5-Hexanedione Under Acidic Conditions

A growing interest in the electrochemical conversion of biomass-derived compounds is attributed to the extremely high sustainability of this process, which has the potential to generate value-added products and renewable electricity from biowastes. The design and synthesis of a high surface area-interconnected porous network of metal nanomaterials are desirable for their application in the field of catalysis. In this work, the synthesis of the carbon-supported Ag nanoparticle aerogel (Ag-aerogel-CNx) for electrocatalytic hydrogenation of 5-(hydroxymethyl)furfural (HMF) is studied. The conversion of HMF to 2,5-hexanedione (HD) via ring opening using ambient pressure and temperature is demonstrated. Here, water is used as the hydrogen source and silver is used as the metal catalyst, which eliminates the use of H-2 gas and the conventional method of hydrogenation that uses high pressure and temperature, which makes this reduction process more practical and efficient to produce HD. We investigated the most favorable potential for high Faradic efficiency and provided a plausible reduction path from HMF to HD. The production of HD is strongly dependent on the cathode potential and the nature of the electrolyte. The tuning of the cathodic potential can give high Faradic efficiency and suppress the other undesired byproducts like H-2. A high Faradic efficiency of 78% and selectivity of 77% are observed for the conversion of HMF to HD on Ag-aerogel-CNx at -1.1 V versus Ag/AgCl in 0.5 M H2SO4. This direct six-electron reduction of HMF to HD can provide a new route to produce valuable intermediates from biomass.

Automated summary

There is a growing interest in the electrochemical conversion of biomass-derived compounds due to the high sustainability and potential for generating value-added products and renewable electricity. In this study, a carbon-supported silver nanoparticle aerogel was synthesized and used as a catalyst for the electrocatalytic hydrogenation of 5-(hydroxymethyl)furfural. The conversion of furfural to hexanedione was demonstrated using ambient pressure and temperature, eliminating the need for high pressure and temperature. The results showed high Faradic efficiency and selectivity for the conversion of furfural to hexanedione under certain conditions.