STTR Phase I: Highly Efficient and Robust Photocatalyst Systems for CO2 Conversion to Valuable Fuels Using Renewable Solar

The broader impact/commercial potential of this STTR Phase I project is in reducing carbon dioxide emissions while delivering a sustainable solution to meet the global demand for green fuels and chemicals. Carbon dioxide is a major greenhouse gas linked to climate change and environmental concerns. Solutions to sequester carbon dioxide underground and in deep oceans are expensive, and the long-term effectiveness, safety, and associated environmental impacts are unclear. This project allows highly efficient conversion of carbon dioxide into valuable green products using only renewable solar energy. The cost-effective, sustainable production of green fuels utilizing carbon dioxide as a feedstock will be key to reducing emissions and lowering dependency on fossil-based sources. Low-cost green fuels, such as methane, are expected to accelerate the penetration of a $30 billion market for the transportation and power generation sectors. This project addresses the fact that the high stability of carbon dioxide and conventional approaches to convert these molecules involve high temperature, high pressure, and/or extremely reactive reagents, rendering them expensive and harmful to the environment. Artificial photosynthesis is a promising approach to convert carbon dioxide and water into commercially valuable chemical products, such as methane, methanol, formic acid and syngas, using only solar energy. This project will assess the technical feasibility of a revolutionary artificial photosynthesis system based on photocatalyst wafers prepared using magnetron sputter epitaxy (MSE) to generate green methane from carbon dioxide in a single step. The proposed project utilizes low-cost, scalable processes to prepare photocatalyst wafers with high efficiencies and stabilities that can be extrapolated to 20+ years of operation lifetime. The key challenge is to effectively combine the novel carbon dioxide reduction functionality with the unique light harvesting and water oxidation platform, and optimize the operating parameters to enhance the overall system efficiency and robustness. The goal is to demonstrate photocatalyst wafers with 10+% solar to fuel efficiencies, unprecedented long-term stability in the carbon dioxide reduction process, and a bench-scale prototype for performance validation. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.