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William Lloyd Evans Lecture

photo of daniel nocera
October 6 - October 7, 2016
12:15PM - 6:15AM
MP 1000, CBEC Lobby, CBEC 130

Date Range
Add to Calendar 2016-10-06 12:15:00 2016-10-07 06:15:00 William Lloyd Evans Lecture Time: Various Event Host: Department of Chemistry & Biochemistry Short Description: The latter property of self-healing is a critical discovery as it allows for the facile integration of the artificial OEC catalyst, together with a hydrogen evolving catalyst (HEC), onto a silicon (Si) wafer in a buried junction configuration. The OEC | triple-junction Si | HEC configuration gives rise to the artificial leaf, which produces hydrogen and oxygen when solar light shines on neutral water, at atmospheric pressure and room temperature. Thursday, Oct. 6, 2016"A Complete Artificial Photosynthesis" - 4-5:15 p.m., MP1000The artificial leaf was invented to accomplish the solar fuels process of natural photosynthesis – the splitting of water to hydrogen and oxygen using sunlight. To create the artificial leaf, four properties of the oxygen evolving complex of Photosystem II (OEC-PSII) were mimicked: An artificial catalyst was created that:possessed the same cubane structure of OEC-PSIIself-assembled from waterpossessed the proton-electron inventory of the Kok cycle used by the OEC-PSII for water splittingwas self-healingThe latter property of self-healing is a critical discovery as it allows for the facile integration of the artificial OEC catalyst, together with a hydrogen evolving catalyst (HEC), onto a silicon (Si) wafer in a buried junction configuration. The OEC | triple-junction Si | HEC configuration gives rise to the artificial leaf, which produces hydrogen and oxygen when solar light shines on neutral water, at atmospheric pressure and room temperature.  But natural photosynthesis does more than split water. Natural photosynthesis has evolved to combine the hydrogen, produced from solar-driven water splitting, with carbon dioxide to produce biomass. We have achieved an authentic and complete artificial photosynthesis. Using the tools of synthetic biology, a bio-engineered bacterium has been developed to convert carbon dioxide, along with the hydrogen produced from the artificial leaf, into biomass and liquid fuels, thus closing an entire artificial photosynthetic cycle. This hybrid microbial | artificial leaf system scrubs 180 grams of CO2 from air, equivalent to 230,000 liters of air per 1 kWh of electricity. This hybrid device, called the bionic leaf, operates at unprecedented solar-to-biomass (10.7%) and solar-to-liquid fuels (6.2%) yields, greatly exceeding the 1% yield of natural photosynthesis.Reception and Poster Session in CBEC Lobby following lecture. Friday, Oct. 7, 2016"Proton-Coupled Electron Transfer Chemistry of Energy Conversion Catalysis" - 4:10-5:30 p.m., 130 CBECSolar-to-fuels generation requires the rearrangement of stable chemical bonds with light as the impetus for the fuel-forming reaction. All such reactions, regardless of the specific fuel, require the transfer of multiple electrons and protons. Energy barriers to such bond rearrangements are minimized only if electrons are efficiently coupled to protons. Catalysts can mediate this coupling, and as well as it does so, determines the solar-to-fuels efficiency.We have created molecular and heterogeneous catalysts to enable us to study the PCET activation mechanism associated with oxygen evolution reaction (OER), oxygen reduction reaction (ORR), hydrogen evolution reaction (HER) and the carbon dioxide reduction reaction (CDR). Electrochemical and photochemical techniques have been constructed to afford a PCET-mechanistic description of associative O–O and H–H bond-formation and of dissociative O–O and C–O bond-cleavage, as these are the crucial activation processes for OER, HER, ORR and CDR, respectively. The molecular complexes incorporate critical chemical and physical properties of heterogeneous energy conversion catalysts, providing a launch point to begin understanding the mechanisms of heterogeneous catalysts at a detailed atomistic level. The combination of a portfolio of experiments spanning PCET mechanism from the molecular to the solid state provides a powerful insight to the crucial steps for the efficient conversion of small molecules to fuels.For more information visit the Department of Chemistry and Biochemistry.  MP 1000, CBEC Lobby, CBEC 130 College of Arts and Sciences asccomm@osu.edu America/New_York public
Time: Various
Event Host: Department of Chemistry & Biochemistry
Short Description: The latter property of self-healing is a critical discovery as it allows for the facile integration of the artificial OEC catalyst, together with a hydrogen evolving catalyst (HEC), onto a silicon (Si) wafer in a buried junction configuration. The OEC | triple-junction Si | HEC configuration gives rise to the artificial leaf, which produces hydrogen and oxygen when solar light shines on neutral water, at atmospheric pressure and room temperature.


Thursday, Oct. 6, 2016

"A Complete Artificial Photosynthesis" - 4-5:15 p.m., MP1000

The artificial leaf was invented to accomplish the solar fuels process of natural photosynthesis – the splitting of water to hydrogen and oxygen using sunlight. To create the artificial leaf, four properties of the oxygen evolving complex of Photosystem II (OEC-PSII) were mimicked: An artificial catalyst was created that:

  1. possessed the same cubane structure of OEC-PSII
  2. self-assembled from water
  3. possessed the proton-electron inventory of the Kok cycle used by the OEC-PSII for water splitting
  4. was self-healing

The latter property of self-healing is a critical discovery as it allows for the facile integration of the artificial OEC catalyst, together with a hydrogen evolving catalyst (HEC), onto a silicon (Si) wafer in a buried junction configuration. The OEC | triple-junction Si | HEC configuration gives rise to the artificial leaf, which produces hydrogen and oxygen when solar light shines on neutral water, at atmospheric pressure and room temperature.  

But natural photosynthesis does more than split water. Natural photosynthesis has evolved to combine the hydrogen, produced from solar-driven water splitting, with carbon dioxide to produce biomass. We have achieved an authentic and complete artificial photosynthesis. Using the tools of synthetic biology, a bio-engineered bacterium has been developed to convert carbon dioxide, along with the hydrogen produced from the artificial leaf, into biomass and liquid fuels, thus closing an entire artificial photosynthetic cycle. This hybrid microbial | artificial leaf system scrubs 180 grams of CO2 from air, equivalent to 230,000 liters of air per 1 kWh of electricity. This hybrid device, called the bionic leaf, operates at unprecedented solar-to-biomass (10.7%) and solar-to-liquid fuels (6.2%) yields, greatly exceeding the 1% yield of natural photosynthesis.

Reception and Poster Session in CBEC Lobby following lecture. 

Friday, Oct. 7, 2016

"Proton-Coupled Electron Transfer Chemistry of Energy Conversion Catalysis" - 4:10-5:30 p.m., 130 CBEC

Solar-to-fuels generation requires the rearrangement of stable chemical bonds with light as the impetus for the fuel-forming reaction. All such reactions, regardless of the specific fuel, require the transfer of multiple electrons and protons. Energy barriers to such bond rearrangements are minimized only if electrons are efficiently coupled to protons. Catalysts can mediate this coupling, and as well as it does so, determines the solar-to-fuels efficiency.

We have created molecular and heterogeneous catalysts to enable us to study the PCET activation mechanism associated with oxygen evolution reaction (OER), oxygen reduction reaction (ORR), hydrogen evolution reaction (HER) and the carbon dioxide reduction reaction (CDR). Electrochemical and photochemical techniques have been constructed to afford a PCET-mechanistic description of associative O–O and H–H bond-formation and of dissociative O–O and C–O bond-cleavage, as these are the crucial activation processes for OER, HER, ORR and CDR, respectively. The molecular complexes incorporate critical chemical and physical properties of heterogeneous energy conversion catalysts, providing a launch point to begin understanding the mechanisms of heterogeneous catalysts at a detailed atomistic level. The combination of a portfolio of experiments spanning PCET mechanism from the molecular to the solid state provides a powerful insight to the crucial steps for the efficient conversion of small molecules to fuels.

For more information visit the Department of Chemistry and Biochemistry

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