FOR IMMEDIATE RELEASE
Mar. 1, 2014 - WASHINGTON, Feb. 27, 2014 — Advances in renewable and sustainable energy, including mimicking photosynthesis and optimizing lithium-ion batteries, are the topics of three plenary talks at the 247th National Meeting & Exposition of the American Chemical Society (ACS), the world’s largest scientific society, taking place here through Thursday.
The presentations, which are among the more than 10,000 scheduled to take place at the meeting, will be held on Sunday, March 16, from 3 to 5 p.m., Ballroom A of the Dallas Convention Center.
As fossil fuel reserves become depleted, researchers are seeking alternative energy sources. Turning to green, leafy plants for inspiration, they are designing so-called molecular machines that mimic photosynthesis, converting the energy in the sun’s rays and water into fuels and electricity. Two plenary talks will discuss this topic. But the fuels and electricity from artificial photosynthesis, as well as from other alternative energy methods, need to be stored for future use. Thus, another plenary talk will address new methods and materials for fuel cells and lithium-ion batteries.
- Jens K. Nørskov, Ph.D.: “Catalysis for sustainable energy”
- Héctor Abruña, Ph.D.: “Operando methods for characterization of Fuel-Cell'>fuel cell and battery materials”
- Michael R. Wasielewski, Ph.D.: “Molecular approaches to solar energy conversion.”
The American Chemical Society is a nonprofit organization chartered by the U.S. Congress. With more than 161,000 members, ACS is the world’s largest scientific society and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.
Essentially all sustainable energy systems rely on the energy influx from the sun. In order to store solar energy it is most conveniently transformed into a chemical form, a fuel. The key to provide an efficient transformation of energy to a chemical form is the availability of suitable catalysts, and we will need to find new catalysts for a number of processes if we are to successfully synthesize fuels from sunlight. Insight into the way the catalysts work at the molecular may prove essential to speed up the discovery process. The lecture will discuss some of the challenges to catalyst discovery, the associated challenges to science as well as some approaches to molecular level catalyst design. Specific examples will include the photo-electrochemical water splitting and carbon dioxide reduction reactions.
This presentation will deal with the development of operando methods for the study and characterization of Fuel-Cell'>fuel cell and battery materials. The presentation will begin with a brief overview of the methods employed. Particular emphasis will be placed on the use of X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS), transmission electron microscopy (TEM) under active potential control, confocal Raman and differential electrochemical mass spectrometry (DEMS). The utility of these methods will be illustrated by selected examples including conversion reactions of Mn3O4 as anode material for lithium ion batteries (LIBs), spectroscopic studies of Li/S batteries and the use of DEMS to characterize electrolyte systems for LIBs. The use of operando TEM will be illustrated by studies of Fuel-Cell'>fuel cell catalyst degradation and coalescence and lithiation/de-lithiation dynamics of LiFePO4via energy-filtered TEM. The presentation will conclude with an assessment of future directions.
Natural photosynthesis is carried out by organized assemblies of photoreceptors and catalysts within proteins that provide specifically tailored environments to optimize solar energy conversion. The photoactive molecules used in artificial photosynthetic systems for solar fuels production and in organic photovoltaics (OPVs) for solar electricity generation require significant molecular order to achieve high performance. Artificial photosynthetic systems for solar fuels formation must be robust assemblies that collect light energy, separate charge, and transport charge to catalysts, while comparable systems for OPVs must transport electrons and holes across interfaces to electrodes. The design and synthesis of complex, covalent molecular systems comprising chromophores, electron donors, and electron acceptors, which mimic both the light-harvesting and the charge separation functions of photosynthetic proteins, have been demonstrated; yet, the development of analogous self-ordering and self-assembling components is still in its early stages. We are developing a variety of molecular building blocks that address the many common issues associated with molecular systems for solar fuels and electricity production.