Lecture abstract

Abstract

The greatest challenge facing our global future is energy. Rising living standards of a growing world population will cause global energy consumption to increase dramatically over the next half century. Within our lifetimes, energy consumption will increase at least two-fold, from our current burn rate of 12.8 TW to 28 35 TW by 2050 (TW = 10 to the power twelve watts; this unit is convenient because it normalizes energy use per unit time, i.e., it is a burn rate). The challenge for science is to meet this energy need in a secure, sustainable and environmentally responsible way.

To place this challenge into perspective, consider the total amounts of possible energy from the following sources:

• From biomass, 7 - 10 TW: This is the maximum amount of biomass energy available from the entire agricultural land mass of the planet.
• From nuclear, 8 TW: To deliver this TW value with nuclear energy will require the construction of 8000 new nuclear power plants. Over the next 45 years, this would require the construction of one new nuclear power plant every two days.
• From wind, 2.1 TW: This energy is harvested by saturating the entire class 3 (the wind speed required for sustainable energy generation, 5.1 m/s at 10 m above the ground) and greater global land mass with wind mills.
• From hydroelectric, 0.7 - 2.0 TW: This energy is achieved by placing dams in all remaining rivers on the earth.

Under the untenable scenarios of the bulleted points listed above, an energy supply for 2050 is barely attained. The message is pretty clear. The additional energy needed for 2050, over the current 12.8 TW energy base, is simply not attainable from long discussed sources the global appetite for energy is simply too much. Petroleum-based fuel sources (i.e., coal, oil and gas) could be increased. However, deleterious consequences resulting from external drivers of economy, the environment, and global security dictate that this energy need be met by renewable and sustainable sources.

Of the possible sustainable and renewable carbon-neutral energy sources, sunlight is preeminent. If photosynthesis can be duplicated outside of the leaf an artificial photosynthesis if you will then the suns energy can be harnessed as a fuel. The combination of water and light from the sun can be used to produce hydrogen and oxygen. The hydrogen can then be combined with the oxygen in a fuel cell to give back water and energy. In the overall cycle, sunlight is converted to useful energy. But here is the catch. A response to this grand challenge of using water and sunlight to make a clean and sustainable fuel to power the planet faces a daunting endeavor - large expanses of fundamental molecular science await discovery for light-based energy conversion schemes to be enabled.

This talk will place the scale of the global energy issue in perspective and then discuss some of the basic science that is needed to emulate photosynthesis. With this basic science in place, the design of catalysts that produce hydrogen and oxygen from water will be presented.

Biography

Professor Daniel Nocera attended Rutgers University where he received a B.S. in Chemistry, graduating with Highest Honors in 1979. He subsequently moved to the California Institute of Technology where he began research on electron transfer reactions in biological and inorganic systems. After earning his Ph.D. degree in 1984, he accepted an appointment in the Chemistry Department at Michigan State University where he was promoted to Professor in 1990. In mid-summer 1997, he joined the Faculty of the Massachusetts Institute of Technology where he is currently a Professor of Chemistry.

He is W.M. Keck Professor of Energy at the Massachusetts Institute of Technology and is widely recognized in the world as a leading researcher in energy at the molecular level. He studied the basic mechanism of energy conversion in biology and chemistry with primary focus in recent years in the photogeneration of hydrogen and oxygen and pioneered each of these areas of science. He created the field of proton-coupled electron transfer (PCET) at a mechanistic level with the publication of the first ultrafast laser study of an electron transfer through a hydrogen bonded interface. His research group focuses on the mechanisms of energy conversion in chemistry and biology. One of his current projects focuses on the potential of solar energy schemes to produce alternative fuels like hydrogen.

This lecture is being supported by the Photochemical and Photobiological Sciences (PPS) Journal, published by the Royal Society of Chemistry.