This is the latest in a series of profiles of our MIT Energy Fellows – graduate students who are supported by MIT Energy Initiative (MITEI) members to participate in faculty-led research and become part of a long-term community of students and alumni.
Bottling up the sun’s energy for a rainy day has been as elusive as grasping and holding a ray of light. D. Kwabena Bediako hopes to exploit a little-understood chemical transformation to enable solar energy to be stored until it’s needed.
Bediako is one of 47 MIT Energy Fellows supported by MITEI’s member companies in 2009-2010. Sponsored by MITEI sustaining member Saudi Aramco, Bediako is working with Professor Daniel G. Nocera, the Henry Dreyfus Professor of Energy and Professor of Chemistry, to develop electrocatalysts—electrodes made of materials that help split water into hydrogen and oxygen without being consumed in the process.
Water-splitting—a process that mimics plants’ ability to use sunlight to generate energy—allows researchers to store energy produced by photovoltaics, for instance, in the chemical bonds of oxygen and hydrogen.
Photons, or light energy, may be captured with catalysts made of certain metals on the surface of a photovoltaic cell. These catalysts in turn use the energy to act on water and rearrange its bonds to produce hydrogen and oxygen. In this way, solar photons are converted into high-energy chemical bonds that can be released in a fuel cell.
“Wide-scale utilization of renewable and carbon neutral energy sources such as solar energy will be dependent on our ability to store this energy efficiently and in a cost-effective manner,” Bediako said. Hydrogen’s energy density beats that of fossil fuels with potentially no carbon footprint.
“I find my research very stimulating and relevant, because to the extent that we can understand the process of water-splitting and how to prepare materials that can effect this transformation efficiently, we can expect that we will come closer to the vision of carbon-neutral energy,” he said.
Global returns
Growing up in Ghana, West Africa, Bediako was drawn to chemistry in high school by a teacher who inspired him to see chemistry research as essential to impacting the standard of living in society.
Even then, he had his sights set on MIT. “MIT is well-known as a great institution throughout the world. Ghana is no exception. I knew of MIT’s reputation,” he said. He hopes to one day return to Ghana and establish a research center in which local students can study the energy problem and be involved in cutting-edge research.
After completing an undergraduate degree in chemistry in 2008 at Calvin College in Grand Rapids, Michigan, he worked for a year in the petroleum-refining laboratories of UOP-Honeywell in Des Plaines, Illinois, before applying to graduate work in energy research at MIT. He said MIT’s focus on “big picture” problems resonated deeply with him.
“So far, I am very happy with the program, and I cannot imagine myself more satisfied anywhere else,” he said. “My classes have given me the opportunity to learn from professors who are at the forefront of their fields. And MITEI, which has brought many speakers from outside MIT, has given me the opportunity to put my research in perspective and understand the larger issue.
“I am certain that these and other efforts of MIT will be highly influential in calling the world’s attention to what is one of the greatest scientific challenges of our generation,” he said.
He is excited to be working toward a potential solution to the global energy crisis, but warns that as alluring as it is to think of sun and water as limitless, clean energy sources, solar energy may not provide a panacea. “I do think we will have to make sacrifices in how we live,” he said. “As we look ahead and develop new energy technologies, we cannot continue in our trend of energy consumption and solve the energy crisis. Our current energy crisis is in part a ramification of our wasteful consumption, and we will have to learn to live less wastefully.”