Electrochemical Conversion of Muconic Acid to Biobased Diacid Monomers

Electrocatalysis is evolving as a competitive alternative to conventional heterogeneous catalysis for the conversion of platform chemicals from biomass. Here, we demonstrate the electrocatalytic conversion of cis,cis-muconic acid, a fermentation product, to trans,trans-muconic acid, trans-3-hexenedioic acid, and adipic acid used for the production of biobased polyamides and polyesters such as nylon, nylon derivatives, and polyethylene terephthalate (PET). The electrocatalytic hydrogenation in this work considers a wide range of early, late, and post-transition metals (Cu, Fe, Ni, Mo, Pb, Pd, Sn, and Zn) with low and high hydrogen overpotentials, and varying degrees of metal hydrogen binding strengths. The binding strength was determined to be an important factor for the conversion rate, faradaic efficiency, and product distribution. Selectivities are also discussed in relation to thermodynamic data, which suggests the possibility to tune the kinetics of the reaction to allow for the variable production of multiple biobased monomers.