Electrocatalytic hydrogenation of furfural using non-noble-metal electrocatalysts in alkaline medium

Abstract

The production of bio-oil from agricultural waste is a promising route to improve the agricultural value chain. Herein, furfural (FF), a model bio-oil compound, was subjected to electrocatalytic hydrogenation (ECH) in an alkaline medium to produce economically important furfuryl alcohol (FA) and hydrofuroin (HF). The selectivity of ECH products (FA and HF) on Cu, Pt, and Ni-foam electro-catalysts showed that their generation was dependent upon the availability of H_ads, which in turn varied with the choice of electrocatalyst and applied potential. Cu–NPNi/NF was obtained through dealloying Cu from a co-electrodeposited Ni–Cu electrode on a Ni-foam substrate, followed by re-electrodeposition of Cu. A porous, high-surface-area bimetallic Ni–Cu catalyst (Cu–NPNi/NF) on Ni-foam yielded high rates of FA and HF generation from furfural, e.g. 118.7 ± 8 and 176.3 ± 3.4 μmol h⁻¹ cm⁻² at −1.45 V vs. Ag/AgCl/sat KCl after 1 h of electrolysis in an alkaline electrolyte. 100% conversion of furfural was observed after 2 h of electrolysis with the same catalyst. The high rate of FA and HF formation was ascribed to enhanced adsorbed FF because of the formation of Cu-nanoplates and bimetallic Ni–Cu. We have provided a rational, high-throughput design for preparing highly active nanoporous electrodes for producing industrially relevant chemicals (furfuryl alcohol and hydrofuroin).