RAISE: CET: Solar-powered Electrolysis for Hydrogen Production from Seawater

Cornell University, Ithaca NY

Investigators

Abstract

This Research Advanced by Interdisciplinary Science and Engineering (RAISE) award is made in response to Dear Colleague Letter 23-109, as part of the NSF-wide Clean Energy Technology initiative. Hydrogen, a clean alternative to fossil fuels and one of the only zero-emission solutions to high-capacity and long-term energy storage, can provide a viable solution to the deep decarbonization of energy systems and thus bring profound impacts on climate change mitigation. Taking advantage of the most abundant and widely accessible renewable energy on Earth, splitting water using natural sunlight could not only meet potential hydrogen demand but also enable a fully sustainable approach without carbon emissions, i.e., green hydrogen production. Despite the great promise, existing solar-powered green hydrogen technologies suffer from (1) limited energy conversion efficiency (< 10% solar-to-hydrogen conversion efficiency) and (2) substantial clean water consumption (> 9 liters of water per kilogram of hydrogen), which has posed significant challenges to making real-world impacts. The overarching goal of this project is to design, develop, and optimize a sustainable electrolytic system with natural sunlight and seawater as the sole inputs, which is expected to achieve a promising solar-to-hydrogen efficiency with additional clean water as the byproduct. The research will be integrated into STEM education and workforce development by equipping graduate students with interdisciplinary expertise through hands-on research projects, incorporating cutting-edge topics of clean energy technologies into undergraduate and graduate courses, and hosting high-school and undergraduate students through workshops and summer research programs. Furthermore, the project aims to increase public awareness of clean energy technologies by displaying the prototype and performing field demonstrations in local communities. The research aims to develop a high-efficiency, low-cost, and off-grid solar-powered seawater electrolysis strategy for green hydrogen production combining interdisciplinary expertise in heat and mass transfer, electrochemistry, and material science. Realization of the design relies on the full-spectrum utilization of solar energy, which requires a mechanistic understanding of (1) the solar-electricity-water conversion to realize the optimal photovoltaic efficiency and solar evaporation rate, (2) the water-hydrogen conversion to approach the electrochemical kinetic limits of hydrogen evolution and the maximum clean water production, and (3) the coupling of key components toward the theoretical limits of solar-to-hydrogen conversion efficiency. The research will not only advance the fundamental understanding of energy conversion and transport associated with green hydrogen, but also demonstrate a fully sustainable pathway toward unprecedented solar-to-hydrogen efficiency and clean water production with natural sunlight and seawater as the sole inputs. 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.