Abstract: Carbon capture, utilization, and storage (CCUS) are critical for managing anthropogenic carbon dioxide (CO2) emissions. Great strides have been made in electrification so far, but there are a handful of scenarios that still require hydrocarbon fuels and chemicals, such as aviation, long-haul trucking, and marine shipping. On the one hand, atmospheric CO2 is only 420 ppm, and using alkaline sorbents for direct air capture is energy intensive; and there are issues with carbon utilization during electrochemical CO2 reduction. On the other hand, atmospheric CO2 exchanges with surface water constantly, and the concentration of dissolved inorganic carbon (DIC) in the Great Lakes or the oceans is approximately 140 times higher in carbon molarity than atmospheric CO2. Thus, capturing and converting DIC in seawater represents an alternative approach to CO2 direct air capture. For these new opportunities, our group studies light-driven catalysis coupled with chemical transport and energy transfer across multiple scales. I will show that these fundamental solar photochemistry studies lead to the record efficiency (>85% quantum efficiency) and stability (>1000 hours) recently reported in photocatalysis.
Photocatalysis concerns multiple redox reactions located within nanoscale distances: I will first elucidate the chemical physics of coupled processes during photocatalysis; and then, I will describe the design and realization of 3D-printed reactors. For practice, combining light-driven photocatalysis with reactive transport using engineered photo-reactors enables the direct conversion of the 2.3-millimolar dissolved bicarbonate to syngas under sunlight. It saves over 50% of the energy over stepwise flue gas capture and conversion and shows the highest solar-to-fuel conversion efficiency for an earth-abundant BiVO4/Si system.
Short bio: Dr. Shu Hu is an Assistant Professor in the Department of Chemical and Environmental Engineering at Yale University, joint with the newly formed Energy Sciences Institute on the Yale West Campus. Dr. Hu studies light-driven catalysis coupled with chemical transport and energy transfer across multiple scales, leading to the record efficiency and stability recently reported in the photocatalysis field.
His group's impact has been recognized through several awards including the DOE Early Career Award, ECS Young Investigator Award for Energy Technology, MRS Emerging Researcher, and Global Chinese Chemical Engineer Awards, and was given several named lectureships including the Schottky Lectureship at TUM and Brown & Williamson Chemistry Lectureship at the University of Louisville. He currently serves as the Secretary of the New England Catalysis Society.
Shu Hu received his Ph.D. from Stanford University in Materials Science and Engineering. Between 2012 and 2015, he did postdoctoral work in the Department of Chemistry with Professor Nathan S. Lewis at California Institute of Technology, where he discovered coating-stabilized photochemical interfaces.
Prof. Hu’s group studies photocatalysis in the context of multi-scale reaction environments. The Hu lab is interested in high quantum efficiency photocatalytic chemical conversion, considered a game changer in sustainable chemical and materials transformation, with research directions spanning from photocatalysis, and semiconductor-liquid interfaces, to nanoscale semiconductor synthesis and operando spectroscopy.
Location:
In-Person Location: Bldg. 440, A105 & A106
Virtual Link: https://argonne.zoomgov.com/j/1613912289