Potential Controlled Selective Oxidation of Glycerol in Anion Membrane Fuel Cell and Continuous Electro-Catalytic Reactors

Biomass is an intriguing renewable and carbon neutral resources and expected to play a big part in the future energy landscape. Bio-renewable glycerol will be mass-produced in the manufacturing of biodiesel.  Glycerol is a highly functionalized molecule featuring vicinal two primary and one secondary hydroxyl groups that has great potential in the construction of major building blocks for the production of new polymers, fine chemicals, pharmaceutical, etc. In this presentation, selective oxidation of glycerol in anion exchange membrane (AEM) fuel cell and continuous electro-catalytic reactors will be discussed. We discovered that electrode potential plays a critical role in controlling the glycerol oxidation product distribution. In a continuous electro-catalytic AEM-based reactor, by tuning the anode potential from 0.35 to 0.65 V (vs. RHE), the selectivity to tartronate dropped from 79% to 26%, while that to mesoxalate increased from 0 to 57% over gold nano-catalyst; At higher potential of 1.6 V (vs. RHE), glycolate can be obtained with a very high selectivity of 85% under mild conditions. Furthermore, we demonstrated that the structure of membrane electrode assembly (MEA) in AEM fuel cell reactor could be tweaked to vary the anode over-potentials, so as to simultaneous generate the valuable mesoxalate or tartronate as well as electricity. This work opens up a new route to sustainable producing valuable chemicals from bio-renewable polyols.