The electrocatalytic hydrogenation of furanic compounds in a continuous electrocatalytic membrane reactor

Abstract

The electrocatalytic hydrogenation of biomass derived oxygenates in a continuous electrocatalytic membrane reactor presents a promising method of fuel and chemical production that minimizes usage of solvents and has the potential to be powered using renewable electricity. In this paper we demonstrate the use of a continuous-flow electrocatalytic membrane reactor for the reduction of aqueous solutions of furfural into furfuryl alcohol (FA), tetrahydrofurfuryl alcohol (THFA), 2-methylfuran (MF) and 2-methyltetrahydrofuran (MTHF). Protons needed for hydrogenation were obtained from the electrolysis of water at the anode of the reactor. Pd was identified as the most active monometallic catalyst of 5 different catalysts tested for the hydrogenation of aqueous furfural with hydrogen gas in a high-throughput reactor.Thus Pd/C was tested as a cathode catalyst for the electrocatalytic hydrogenation of furfural. At a power input of 0.1W, Pd/C was 4.4 times more active ( per active metal site) as a cathode catalyst in the electrocatalytic hydrogenation of furfural than Pt/C. The main products for the electrocatalytic hydrogenation of furfural were FA (54-100% selectivity) and THFA (0-26% selectivity). MF and MTHF were also detected in selectivities of 8%. Varying the reactor temperature between 30 °C and 70 °C had a minimal effect on reaction rate for furfural conversion. Using hydrogen gas at the anode, in place of water electrolysis, produced slightly higher rates of product formation at a lower power input. Sparging hydrogen gas on the cathode had no effect on reaction rate or selectivity, and was used to examine the addition of recycling loops to the continuous electrocatalytic membrane reactor. † Electronic supplementary information (ESI) available. See

Controlling Competitive Side Reactions in the Electrochemical Upgrading of Furfural to Biofuel

“…According to previous reports, two reaction pathways for the ECH of FF exist as depicted in Scheme a: a direct and an indirect reaction for the production of MF from FF. The Li group showed direct conversion of FF to MF at low applied potential (−0.55 V vs. RHE) on Cu, having negligible conversion of FA to MF.…”

“…The standard redox potential (vs. reversible hydrogen electrode, RHE) for the HER is 0 V at pH 0. The standard redox potentials for the ECH of FF to FA, ECH of FA to MF, and ECH of FF to MF are +0.19 V, +0.13 V, and +0.31 V, respectively. This indicates that the ECH of FF is favored over the HER thermodynamically.…”

Stabilizing cobalt catalysts for aqueous-phase reactions by strong metal-support interaction

“…These are all key platform renewable non-petroleum based molecules [49,50]. Hydrogenation of furfuryl alcohol and furfural has been studied using Pt, Pd, and Ru catalysts [51][52][53][54][55]. Hydrogenation of carbohydrates (e.g., xylose to xylitol) is an industrial process using Ru catalysts [11].…”

Electrocatalytic Hydrogenation of 5‐Hydroxymethylfurfural in Acidic Solution

“…[11] Recently,C hadderdon et al reported electrocatalytic oxidation of HMF on supportedg old and palladium bimetallic nanoparticles, showing that Pd 1 Au 2 /C oxidizes HMF selectively to FDCA with 83 %y ield in alkaline conditions (0.02 m HMF in 0.1 m KOH, 100 %c onversion in 1h,0 .9 V RHE ,2 58 C). [13] Green et al [14] also investigated furfural hydrogenation on aP d/C cathode catalysti napolymer electrolyte membrane (PEM) electrolyzer and reported that furfuryl alcohol with 54~100 %s electivity was obtained in water-based neutral pH. Similarly,f urfural (C 5 H 4 O 2 ), Electrocatalytic hydrogenation of 5-hydroxymethylfurfural (HMF) is studied on solid metal electrodes in acidic solution (0.5 m H 2 SO 4 )b yc orrelatingv oltammetry with on-line HPLC product analysis.…”