Biocatalysis on phase boundary: modelling and design of enzymatic gas-diffusion electrodes – THREENZY

Being efficient and selective, enzymatic biocatalysts composed of abundant elements may successfully replace abiotic heterogeneous catalysts in sustainable energy applications such as fuel cells, bioreactors and solar fuel cells. The use of enzymes is particularly attractive for the catalytic transformation of small gas molecules such as H2, O2, N2, CH4, CO2, otherwise requiring high energy input to overcome the activation barrier. Yet, the performance of bioelectrodes is often severely limited in the reactions featuring these gases due to their low solubility and incapability of the enzymes to function in the dry state. The purpose of this project is to reconcile biocatalysts with gaseous phase by designing and fabricating gas-diffusion electrodes adapted to enzymatic catalytic systems using both theoretical modelling and experimental investigation.
The project will benefit from the power of numerical calculation to build and optimise the gas-diffusion bioelectrode model while taking into account the peculiarities of enzymatic catalysts. The characteristic properties of enzymes, such as pH-dependence, Michaelis-Menten and electrochemical kinetics or hydration, will be introduced to models based on classic GDL. This will allow to propose a new design of enzymatic gas-diffusion bioelectrode which will be further implemented and validated experimentally on enzymatic models with technological interest. Finally, to ensure the biocatalyst is operating in optimal conditions, protective strategies will be implemented on the optimised bioelectrode.
The project will contribute to the understanding and improvement of the performances of bioelectrodes based on efficient but underrated enzymatic redox catalysts. In the long term, the outcomes of this project are expected to permit the enzymes to replace expensive abiotic catalysts in certain applications in the energetic context.