(205g) Supported Cu Electrocatalysts for Electrocatalytic Hydrogenation and Hydrogenolysis of Furfural

Furfural (FF) is a C₅ biomass-derived platform chemical that can be obtained by hydrolysis and dehydration of lignocellulose. By chemical hydrogenation and hydrogenolysis (CH) of FF, furfural alcohol (FA), an industrial adhesive intermediate, and 2-methyl furan (MF), a promising biofuel, can be produced[1, 2]. Traditionally, CH of FF provides significant selectivity towards to FA and MF on Cu-based catalysts, but it requires externally supplied hydrogen gas and high temperature or/and high pressure[3].

In contrast to CH, electrochemical hydrogenation and hydrogenolysis (ECH) allows for the conversion of FF to FA and MF without external hydrogen gas, high temperature or high pressure. This process becomes more viable when excess electricity from renewable sources is used for ECH of FF.

Results of previous studies showed that strongly acidic electrolytes produced both MF and FA [4], while higher pHs mainly produced FA [5] on bulk metallic electrodes. In ECH of FF, Cu foil electrodes also showed remarkable selectivity (c.a. 80%) to MF in 0.5 M H₂SO₄ [4]. Also, substantial selectivities of FA with carbonate pH 10 buffer (80%) on a Cu foil [6] and with 0.2 M NH₄Cl (79%) on a Ni foil [5] have been demonstrated.

We have experimentally shown further relationships between products and reaction conditions in acidic electrolytes on Cu foil electrodes where product yield significantly depended on the current density when equivalent charge was transferred to the system. However, product selectivity depended on pH, not anions of electrolytes.

Here, we developed high surface area supported Cu electrocatalysts to investigate the impact of morphology on selectivity and activity in comparison with Cu foils in 0.2 M NH₄Cl and 0.5 M H₂SO₄ electrolytes. Electrocatalysts were characterized utilizing XRD, SEM, TEM and XPS to discern the differences in catalytic performance. Product analysis was performed with gas chromatography mass spectrometry (GC-MS).

References

[1] J.N. Chheda, G.W. Huber, J.A. Dumesic, Liquid-phase catalytic processing of biomass-derived oxygenated hydrocarbons to fuels and chemicals, Angew. Chem.-Int. Edit. 46 (2007) 7164-83.

[2] J.-P. Lange, E. vanâ??derâ??Heide, J. vanâ??Buijtenen, R. Price, Furfuralâ??A promising platform for lignocellulosic biofuels, ChemSusChem 5 (2012) 150-66.

[3] Y. Nakagawa, M. Tamura, K. Tomishige, Catalytic reduction of biomass-derived furanic compounds with hydrogen, ACS Catalysis 3 (2013) 2655-68.

[4] P. Nilges, U. Schröder, Electrochemistry for biofuel generation: production of furans by electrocatalytic hydrogenation of furfural, Energy & Environmental Science 6 (2013) 2925-31.

[5] Z. Li, S. Kelkar, C.H. Lam, K. Luczek, J.E. Jackson, D.J. Miller, C.M. Saffron, Aqueous electrocatalytic hydrogenation of furfural using a sacrificial anode, Electrochimica Acta 64 (2012) 87-93.

[6] P. Parpot, A.P. Bettencourt, G. Chamoulaud, K.B. Kokoh, E.M. Belgsir, Electrochemical investigations of the oxidation-reduction of furfural in aqueous medium: Application to electrosynthesis, Electrochimica Acta 49 (2004) 397-403.