Water is a vastly preferred source for hydrogen, one of the most promising green fuels for the establishment of a sustainable and environmentally friendly energy cycle. This close cycle would work through the use of renewable energy for splitting water into its components: oxygen and hydrogen; and then extracting the stored energy recombining them back to water via fuel cells, for example.
However, water-splitting technologies are still far from being economically competitive for mass production. This is a major issue to support a societal change in the energy paradigm: industrial high purity electrolytic hydrogen is still, at least, four times more expensive than the very cheap hydrogen obtained from steam reforming. Therefore, a tremendous research effort is being done in the field to find viable solutions to reduce electrolysis costs. To do so, cost-effective, earth-abundant, efficient and robust catalysts for water splitting are needed, to be incorporated in scalable and industrially-ready processes.
Our research team has been studying novel strategies to facilitate the oxygen evolution reaction (OER), the oxidation half-reaction in water electrolysis, typically considered a bottleneck due to its complexity and high potentials requirement. During the last years, our research group has disclosed very interesting alternatives to provide cost-effective OER electrocatalysis. For this new project, we propose the final integration of these previous successful results into complete electrolytic cells.
For this objective, we will need to optimize our OER electrodes to match the working requirements of the corresponding reduction electrocatalysts for hydrogen evolution (HER), but also for carbon dioxide reduction (CO2R), both key processes for the development of future renewable fuels productions. Our final goal will be the design and construction of two-electrode cells operating at maximum currents and lowest overpotentials, while being exclusively based on abundant raw materials.
Our approach will be multidisciplinary, taking advantage of inorganic chemistry for the preparation and processing of the catalysts; materials science for their incorporation onto electrode supports; physical chemistry for the characterization of materials and electrodes; electrochemistry for the characterization of electrode and cell performance; analytical chemistry for the identification and quantification of products and by-products; and chemical engineering for the design and construction of electrolytic cells.
Through an optimization strategy to match the best electrodes in the corresponding working conditions, complete two-electrode cells will be validated and their performance analyzed in comparison with current technologies, to identify the technological advantages (and disadvantages) of our novel findings. We will also explore the combination of electrolytic cells with renewable energy sources, preferably photovoltaic panels. This additional target will require efficient enough electrolyzers, but also robust under high stress conditions, as those provided by renewable energies, that are intrinsically intermittent, and variable.