Glucose Conversion on Ni-based Electro-Catalysts – GluCoNiC

Lignocellulosic biomass-derived sugars (like glucose) provide a renewable and almost inexhaustible carbon feedstock for sustainable production of fine chemicals. Gluconic acid and sorbitol belong to the top-30 list of value-added chemicals from biomass. Currently, glucose conversion into sorbitol and gluconic acid is performed using either bio-technological or heterogeneous catalytic routes. Electrochemical conversion, with its low environmental footprint, high energy efficiency, tunability and controllability of the process conversion and selectivity, is perfectly compatible with the biomass transformation considering its composition (carbohydrates) and high water content, and becomes increasingly attractive with the growth of the renewable electricity production. The objective of this project is to develop a continuous electrocatalytic reactor, free from strategic platinum group metals, and allowing simultaneous production of gluconic acid at the anode and sorbitol at the cathode. To this end, we will synthesize mono- and bimetallic Ni-based nanomaterials, and systematically study them under well-defined conditions in an electrochemical cell in alkaline media. Fine control of the Ni surface state and addition of other metals will serve as tools to tune the electrocatalytic activity of Ni in the glucose oxidation and reduction reaction. Electrochemical methods, in situ spectroscopic and analytical tools combined with kinetic modeling will aid us determine rate and selectivity of electrochemical reactions depending on the electrode potential, glucose concentration, pH and temperature, and propose reaction mechanisms. Stability of the catalysts towards degradation will be investigated by identical-location transmission electron microscopy and on-line inductively coupled plasma mass spectrometry to probe textural degradation, metal dissolution and nanoparticle detachment. These studies will help designing active and stable Ni-based catalysts and defining operational modes ensuring high durability, selectivity and energy-efficiency. Finally, a continuous flow electrochemical reactor comprising industrially-relevant Ni foam/felt-based electrodes will be developed, allowing simultaneous, selective and energy-efficient production of gluconic acid at the anode and sorbitol at the cathode. The project contributes to the implementation of the French national strategy for bioeconomy validated in 2017. Our ambition is to enable France to move from a fossil fuel-based to a renewable carbon economy. It contributes to the development of cost- and energy-effective means for the transformation and refinery of glucose issued from lignocellulosic biomass (non-edible agricultural, forestry or marine) into high value-added chemicals. Compared to the existing technologies, such an electrochemical process will have a low environmental impact, will help in laying foundation of the French leadership in the next generation of electrochemical clean organic synthesis technologies, and contribute to the fight against climate change.