Goal 3
Develop and validate predictive models for component and interface durability, and the implications for solar to fuel efficiency and selectivity under real-world conditions.
The State of the Art in 2020: The durability of solar fuels systems that have been designed so far is insufficient for real-world use, which requires efficient and stable operation up to 100,000 hours under fluctuating levels of sunlight with impure feedstocks. This is a major bottleneck for the advancement of the science and transition of solar fuels to a technology. The primary degradation mechanisms found so far are loss of catalytic activity and corrosion. Protections against degradation mainly involve providing physical barriers to separate non-durable materials from water, however these barriers may compromise function, and must be perfect to ensure stability under the harsh conditions present in solar fuels generation systems.
LiSA’s Research: Corrosion is well-recognized as a failure mechanism, but very little is understood about the myriad other processes that can influence the photocatalyst or reaction-center microenvironment, and thus drive changes in performance over time. LiSA aims to establish the science of durability as it applies to solar-driven (photo)electrochemical systems that generate liquid fuels. The work is primarily directed toward understanding the fundamental chemical and physical mechanisms that underlie degradation and compromise the function of electrocatalysts and photocatalysts, generating specific descriptors that can be used to predict degradation rates under various conditions. This provides the tools necessary for co-design of materials and combination of materials that have stable performance in photo-driven microenvironments and microenvironment assemblies. It also provides the basis for co-design of light absorbers and their interfaces that are optimized for carrier extraction and catalytic activity, while maintaining stable operation over long periods of time. Corrosion mechanisms, descriptors for co-design, and operational limits of durability are essential for the Hub-wide research strategy of using data science to bridge microscopic processes to complex systems science.
Team Contributions: Work toward this Goal is led by the Durability team, focusing on characterizing the physics and chemistry of degradation processes across time and spatial dimensions. The team works with the Photodynamics team to probe how microenvironments evolve at the atomic, molecular and systems scale under operando conditions. The Photoactive Materials team uses that understanding to co-design photocatalyst materials that have durability-promoting surfaces that are also functional for charge extraction and catalysis. From this foundation, the Chemical Microenvironments and Systems and Integration teams co-design durable systems of microenvironments that are high performing, and incorporate mechanisms for self-repair.
Develop and validate predictive models for component and interface durability, and the implications for solar to fuel efficiency and selectivity under real-world conditions.
Artwork: Darius Siwek