Recent Advances in Furfural Reduction via Electro- And Photocatalysis: From Mechanism to Catalyst Design

Abstract

Furfural has been considered as one of the most attractive biomass platform compounds, which can be valorized into high-value-added chemicals (e.g., hydrofurorin, 2methyl furan, tetrahydrofurorin, furfuryl alcohol, tetrahydrofurfuryl alcohol, and 2methyltetrahydrofuran) and upgraded to functional materials (e.g., synthetic resins, electrical insulation materials, nylon, coatings, and pharmaceuticals). Although the traditional thermocatalytic transformation of furfural is effective, it always requires harsh conditions, especially high temperature and pressure. Accordingly, the reduction of furfural via electro-and photocatalytic approaches has gradually attracted tremendous attention and achieved remarkable progress. Herein, this Review systematically emphasizes the recent advancements in catalysts for valorizing furfural into high-value-added chemicals, biofuels, and additives through electro-and photocatalysis. Moreover, the design strategies of different reactors (i.e., H-cells and flow cells) are clarified. In addition, the application of advanced operando/in situ characterizations and theoretical calculations are highlighted to gain insights into the reaction pathways and catalytic mechanism of the electro-and photocatalytic reduction of furfural. Finally, the current challenges and perspectives are outlined in the field of electro-and photocatalytic furfural conversion.

Flexible and Stretchable Electrodes in Biofuel Cells for Sustainable Power

“…108 Wearable BFCs are one kind of continuous-flow BFCs; however, biomass-valorization continuous-flow BFCs are capable of offering high current density for electrolytic oxidation or reduction of furans derivatives from bioplastics/biomass. 109 H-cell BFCs for accessing hydrofuroin from a flow-cell system with freestanding electrode, wherein the flexibility of the electrode offers advantages. Skin-friendly BFCs are also microfabricated as a single-layer monolith structure of textile to construct a bi-enzyme fuel cell which offered adequate performance and higher longevity than existing fuel cells.…”

Electrocatalytic Hydrogenation of Furfural with Improved Activity and Selectivity at the Surface of Structured Copper Electrodes

“…There remains a debate, however, as to whether these steps occur through an electrochemical hydrogenation (ECH) pathway or through a proton-coupled electron transfer (PCET) pathway . While the first report on the electrocatalytic reduction of FAL dates back to 1939, it has gained a renewed and rapidly growing interest over the past decade and has been the object of several recent perspective and review articles. − Early studies described the electrochemical reduction of FAL in aqueous media (sometimes containing methanol) inside H-cell setups, on a range of metal electrodes – Pt, Ni, Cu, Al, and stainless steel. − Conversely, in more recent studies, Cu has been mostly favored due to its superior activity and selectivity. ,− These works collectively show that, on bare copper, FAL is preferentially converted to FOH under neutral conditions, at applied potentials more negative than −0.5 V vs RHE, while 2-MF is the main product under highly acidic conditions at potentials more negative than −0.45 V vs RHE (see Table S3 for a collection of recent data from the literature). In these studies, the concentration of FAL was in the 0.01–0.1 M range, with the appearance of hydrofuroin as a secondary product at higher concentrations.…”

Electrocatalytic Hydrogenation of Furfural with Improved Activity and Selectivity at the Surface of Structured Copper Electrodes

“…License: CC BY-NC 4.0 1939, 10 it has gained a renewed and rapidly growing interest over the last decade and has been the object of several recent perspective and review articles. [11][12][13][14] Early studies described the electrochemical reduction of FAL in aqueous media (sometimes containing methanol) inside Hcell setups, on a range of metal electrodes -Pt, Ni, Cu, Al, and stainless steel. [15][16][17][18] In more recent studies, Cu has been mostly favored due to its superior activity and selectivity.…”