Topic: Photocatalytic Generation of Solar Fuels and Commodity ChemicalsSpeaker: Assistant Professor Francesca Arcudi, Department of Chemical Sciences, University of Padova (Unipd) Date and time: May 15, 13:30–15:30 Venue: Room 105, #5 Building of SPST Host: Yang Fan
Abstract: This talk will describe two separate strategies to photocatalytically produce (i) CO from CO2, and (ii) polymer-grade ethylene from an ethylene feed with acetylene contaminant. CO2 reduction is accomplished in pure water with an unprecedented combination of performance parameters: turnover number (TON(CO)) >80,000, quantum yield (QY) >3% and selectivity >99%, using CuInS2 colloidal quantum dots (QDs) as photosensitizer and a Co-porphyrin catalyst. The amine/ammonium-terminated ligand shells of the QDs are responsible for the exception performance of this system by establishing (i) an electrostatic assembly with Co-porphyrin, which allow the colocalization of protons, CO2, and catalyst at the QD core that serves at the source of the electrons; (ii) a dynamic equilibrium between carbamic acid and free CO2 that increases the local concentration of available CO2; and (iii) “second-sphere” effects that improve the efficiency of the Co-porphyrin catalyst. In a separate system based on a Co-porphyrin catalyst, acetylene is reduced to ethylene, an intermediate in the production of ~50-60% of all plastics. Our system reduces acetylene into ethylene with several advantages over the present hydrogenation technology, including (i) operation with near 100% conversion in an ethylene-rich gas feed and ≥99% selectivity under both non-competitive (no ethylene co-feed) and competitive (ethylene co-feed) conditions, the latter being industrially relevant; (ii) operation at room temperature using light and water in place of high temperature and an external H2 feed, and (iii) use of cobalt in the catalyst in place of precious metal catalysts. Combining the high activity and selectivity of the homogeneous system with the ease of separability, recyclability, and robustness of a heterogeneous system lends advantages over the homogeneous catalyst, namely, facile recyclability and increased longevity. These features offer substantial advantages over current hydrogenation technologies with respect to selectivity and sustainability.
Biography:
Francesca Arcudi obtained her PhD in 2017 at the University of Trieste, under the supervision of Prof. Maurizio Prato. From 2018 to 2022, Francesca joined Northwestern University in United States as postdoctoral research fellow working with Emily A. Weiss. In late 2022, she was awarded the “Rita Levi Montalcini” Program for Young Researchers for outstanding scholars working abroad to start an independent career in Italy as assistant professor. She is now leading a team at the University of Padova to research strategies for light-powered reactions to produce fuels and commodity chemicals.
Francesca Arcudi obtained her PhD in 2017 at the University of Trieste, under the supervision of Prof. Maurizio Prato. From 2018 to 2022, Francesca joined Northwestern University in United States as postdoctoral research fellow working with Emily A. Weiss. In late 2022, she was awarded the “Rita Levi Montalcini” Program for Young Researchers for outstanding scholars working abroad to start an independent career in Italy as assistant professor. She is now leading a team at the University of Padova to research strategies for light-powered reactions to produce fuels and commodity chemicals.