Electrochemical reactor for sustainable transformation of bio-mass derived allyl alcohol into acrylate and pure hydrogen

Acrylic acid is widely used in the chemical, polymer, cosmetic and food industries. Typically, it is produced through processes with a high environmental impact. In this paper, we demonstrate the co-production of the potassium acrylate salt and hydrogen gas from allyl alcohol in a liquid flow fed anion exchange membrane electrolysis cell operating at 60 °C and ambient pressure. We compare in electrolysis cell tests, two electrocatalysts Pd/C and Pd-CeO2/C evaluating the activity and selectivity for acrylate production. Electrolysis cell parameters are tuned obtaining a maximum conversion of allyl alcohol of 96% and a selectivity to acrylate of 50% at an operating cell voltage of 1 V. Operating at a lower cell potential (0.7 V) the selectivity for acrylate increases to 74%. Hydrogen gas is produced in the separated cathode compartment at an energy cost of 26 KWh kgH2-1, which is around half when compared to state-of-the-art water electrolyzers. The electrochemical oxidation mechanism of allyl alcohol is also studied and discussed, providing for the first time an insight into the pathways for formation of acrylate with respect to the other principle oxidation products (propionate and 3-hydroxypropionate).