Researchers at the University of Cambridge have produced hydrogen from water using a newly designed and inexpensive cobalt catalyst. It’s noteworthy because the cobalt catalyst will work in conditions useful to industry. The catalyst uses simple fresh water, tolerates oxygen in the atmosphere and runs at room temperature.
These attributes set up respectable “Faradaic efficiencies” (electrical use) under N2 and 21% O2 in N2, the usual mixture in the atmosphere, and can be used under both homogeneous and heterogeneous conditions. Just how efficient the catalyst is hasn’t answered by the Cambridge press release or the abstract from the published paper in Angewandte Chemie International Edition.
The new catalyst does face down a major problem, current highly efficient catalysts such as the noble metal platinum are too expensive and cheaper alternatives are typically inefficient.
The leading problem for sunlight to fuel is developing sunlight-driven water splitting for green and sustainable hydrogen.
Lead author of the research, Dr Erwin Reisner, an EPSRC research fellow and head of the Christian Doppler Laboratory at the University of Cambridge, said: “A H2 evolution catalyst which is active under elevated O2 levels is crucial if we are to develop an industrial water splitting process – a chemical reaction that separates the two elements which make up water. A real-world device will be exposed to atmospheric O2 and also produce O2 in situ as a result of water splitting.”
Currently the cheap source of hydrogen is cutting it off from natural gas molecules or high temperatures steam reforming. So far H2 cannot be used as a ‘direct’ substitute for gasoline or ethanol, but it can be used as a fuel in combination with fuel cells, which are already available in cars and buses.
Dr Reisner follows up with, “Until now, no inexpensive molecular catalyst was known to evolve H2 efficiently in water and under aerobic conditions. However, such conditions are essential for use in developing green hydrogen as a future energy source under industrially relevant conditions.”
“Our research has shown that inexpensive materials such as cobalt are suitable to fulfill this challenging requirement. Of course, many hurdles such as the rather poor stability of the catalyst remain to be addressed, but our finding provides a first step to produce ‘green hydrogen’ under relevant conditions.”
With the new cobalt catalyst results in hand the researchers are now working on a solar water splitting device, where a fuel H2 and the by-product O2 are produced simultaneously.
Fezile Lakadamyali and Masaru Kato, co-authors of the study, add: “We are excited about our results and we are optimistic that we will successfully assemble a sunlight-driven water splitting system soon.”
This looks great, now if the team could get the hydrogen ready to store or reconnected to a carbon atom they’d really have something. Either way, when the stability of the cobalt is worked out perhaps more electrolysis will displace the costly natural gas stripping and steam reforming.