Hydrogen has been hailed as the fuel of the future, but producing it cleanly using platinum as a catalyst is simply too costly to service the world's energy needs. On the flipside, producing hydrogen with fossil fuels not only releases CO2 as a byproduct, but is unsustainable, negating hydrogen's green potential. However, hydrogen may yet make good on its promise thanks to a group of scientists at the University of Cambridge.
They found that cobalt can function as an efficient catalyst at room temperature in pH neutral water surrounded by oxygen. Compared to platinum, cobalt is relatively abundant and therefore inexpensive – a recipe that could make all the difference if we're going to complete a transition to alternative energy sources over the next 50 years.
"Until now, no inexpensive molecular catalyst was known to evolve H2 efficiently in water and under aerobic conditions," explains Dr. Erwin Reisner, head of the Christian Doppler Laboratory at the University of Cambridge Department of Chemistry. "However, such conditions are essential for use in developing green hydrogen as a future energy source under industrially relevant conditions."
Currently, the researchers are developing a solar water splitting device that would yield just H2 and O2 – clean fuel and oxygen. "We are excited about our results and we are optimistic that we will successfully assemble a sunlight-driven water splitting system soon," writes Masaru Kato and Fezile Lakadamyali, co-authors of the study published in the journal Angewandte Chemie International Edition in August 2012.
However, cobalt is not a magic bullet. "Many hurdles such as the rather poor stability of the catalyst remain to be addressed," cautions Dr. Reisner. "But our finding provides a first step to produce ‘green hydrogen’ under relevant conditions."
Other groups are working on the same problem, from transferring solar energy to hydrogen for storage to a group that says it has produced hydrogen from sunlight and ethanol. With any luck, future trips to the pump won't be for petrol.
Source: University of Cambridge