There is a crisis in the world’s energy needs. In the next 25 years it is estimated that the world’s energy demands will increase by over a third. One of the grand challenges facing science today is to discover the basis for an energy economy that is efficient, clean, cost-effective, and sustainable. Sunlight is our ultimate source of energy and this energy has been caught and collected over time in combustible fossil fuels (i.e. oil, natural gas and coal) that currently account for the vast majority of our energy consumption, but with well-known drawbacks. The Earth receives more solar energy in one hour than consumed by humans in an entire year. Thus conversion of solar energy into electricity provides a viable long-term solution to our energy needs, but to render this approach practicable efficient storage of this energy is required. Molecular hydrogen can store this energy chemically and release it efficiently as electricity by use of fuel cells. However, cheap and efficient catalysts are required for conversion of electricity into H2 and operation of fuel cells. Nature has found a solution for this problem in the form of [FeFe]-hydrogenase enzymes, whose active site features an organometallic [2Fe2S] butterfly cluster core that efficiently catalyzes the production of H2 from water with little overpotential.
Inspired by this enzyme active site, the researchers have synthesized new organometallic [2Fe2S] chemical analogues, and they serve as cheap and efficient catalysts for electrochemical reduction of weak acids to H2 albeit with substantial overpotentials. The talk on August 16 discussed the fundamental principles of chemical energy, electronic and geometric structure, kinetics and mechanisms for production of molecular hydrogen studied by a variety of chemical, spectroscopic, and computational methods.
