Discussion on the mechanism of the electrocatalytic reduction of furfural using thermodynamic, voltammetry, and simulation methods

Abstract

Electrocatalytic reduction (ECR) of bio-oil (from the pyrolysis of biomass) has attracted great attention because of its operation under ambient conditions and the use of water as a hydrogen donor. Furfural (FF) is an important component of bio-oil. 2-Methylfuran (2-MF) can be used as a gasoline antiknock agent. The ECR of FF to produce 2-MF is investigated. Low temperature is found to be favorable for the ECR of FF and disadvantageous for the formation of H₂. Ni has a higher activity than Cu. For Ni–Cu electrode, the reaction initiates as late as that on Cu, but the conversion becomes faster once reaction starts. A trace amount of Ni²⁺ (10⁻⁷ M) in the electrolyte has nearly no influence on the reaction overpotential but could improve the extent of conversion. The carbonyl bond of furfural is activated when the carbonyl O atom approaches the Cu atom and the carbonyl C atom is close to Ni.