Effects of Temperature on the Faradaic Efficiency of Hydrogenation and Hydrogenolysis of Furfural

Abstract

Alternative sustainable methods for chemical and fuel production are a growing area of interest. One alternative for biomass upgrading, which typically requires high operating temperatures and pressures, as well as externally-supplied hydrogen gas, is to use electrochemistry to undergo the reaction. Using electrochemical methods, the reaction can be run at ambient conditions. In addition, the external hydrogen which comes from energy intensive methods is not necessary because adsorbed hydrogen for biomass conversion can come from the electrolyte. Furfural (FF) reduction to furfuryl alcohol (FA) and 2-methylfuran (MF) is a promising case for the reaction to be performed electrochemically. Furfural electroreduction requires high overpotentials for appreciable partial current densities to desired products which leads to significant hydrogen evolution (HER). In this work we show that the reactions rates to desired and non-desired products vary differently with temperature between 10 to 45 °C when studied over copper electrocatalysts in 0.5M sulfuric acid. This affects the overall Faradaic efficiency for all products and allows for the shift of Faradaic efficiency of products as a function of temperature. The Faradaic efficiency is shown to be a function of both temperature and overpotential allowing one to target higher FE of desired products by tuning both temperature and potential.