Scientists have found and tested an abundant and inexpensive catalyst needed to make hydrogen fuel from sunlight and water, a necessary step on the road to the elusive clean, green hydrogen economy.

The new catalyst — molybdenum sulfide– is an alternative to platinum, an expensive and rare catalyst used to convert single ions of hydrogen split off from water into hydrogen gas.

“That’s the very neat thing here, it is quite inexpensive and abundant,” Jens Norskov, a chemical engineer with the Department of Energy’s SLAC National Accelerator Laboratory at Stanford University, told me Monday.

The dream of a hydrogen economy stems from the fact that hydrogen is an energy dense and clean fuel — upon combustion, it releases water. The problem is that most hydrogen is produced from natural gas in a process that releases carbon dioxide, a greenhouse gas.