British scientists say they have produced hydrogen, a renewable energy source, from water using an inexpensive catalyst under industrially relevant conditions.

Those conditions include using pH neutral water, surrounded by atmospheric oxygen, to produce hydrogen at room temperature, Cambridge University reported Thursday.

"A H2 [hydrogen] 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," Cambridge researcher Erwin Reisner said.

Finding an efficient and inexpensive catalyst that can function under real-world conditions -- in water, under air and at room temperature -- has been a stumbling block, researchers said.

Highly efficient catalysts such as platinum are too expensive and cheaper alternatives are typically inefficient, they said.

Experiments at Cambridge have shown a simple catalyst containing cobalt, a relatively inexpensive and abundant metal, operates as an active catalyst under the condition sought, researchers said.

"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." Reisner said.