Matching supply with demand is a significant issue with the large-scale deployment of intermittent renewable energy systems such as wind and solar power. For example, the peak power generated when the wind blows must be matched to periods of peak demand. This necessitates the development of large and efficient means of temporary power storage. One attractive option is a high performance, reversible, and efficient fuel cell/electrolyzer system. This system would operate in electrolyzer mode to store electrical energy as chemical energy (hydrogen) during periods of plentiful power generation. Operation can then be reversed to supply electrical energy during periods of peak demand.
Intellectual Merit
Proton conducting oxides have potential application in efficient high temperature solid oxide fuel cells and electrolyzers. While the transport properties of these materials are being studied in increasing detail, there is currently very limited knowledge regarding the catalytic and electrocatalytic activity of this class of material. Reduction and oxidation (redox) of surface oxygen sites by the Mars-van Krevelen mechanism is a central step in catalytic and electrocatalytic reaction on oxygen ion conducting materials. The central hypothesis of the proposed research is that an analogous proton-based Mars-van Krevelen mechanism will be a critical step in the catalytic cycle on proton conducting oxides. The central route to enhanced activity will be doping of transition metals both into the oxide lattice and as nanoparticles on the oxide surface. The hypothesized electrocatalytic mechanism will be validated by isotopic transient studies and the measured reaction kinetics related to proton incorporation thermodynamics, transport properties and crystal structure. Proton conducting solid oxide fuel cells and electrolyzers will be fabricated and tested to demonstrate the links between electrocatalysis and electrode function.
The demonstration of a proton based Mars-van Krevelen mechanism will provide a fundamental basis from which the performance of proton conducting oxide electrodes may be interpreted and enhanced.
Broader Impacts
Replacing oxygen ion conductors with proton conducting oxides can provide a new direction for heterogeneous catalyst development. The results of this multidisciplinary study will be disseminated to the catalysis, electrochemistry, and solid state ionics communities through journal publications and conference presentations.
Undergraduate students will play an active role in this research through clearly identified, focused research projects. The importance and potential impact of ongoing scientific advances in the area of energy and the environment will be conveyed to the general public via "Energy days" to be held at the University of Virginia. Faculty and graduate and undergraduate students from across campus actively engaged in this field will provide technology demonstrations and discussion points. A focused approach to engaging middle school students will be developed by expanding a small existing program. The PI, as well as graduate students in the PI's laboratory, will spend a time at local middle schools introducing the concept of engineering to students through a series of hands-on projects. These will be focused on energy and sustainability concepts with learning outcomes reinforced through classroom education.
