A smear of green-brown goop developed at the University of Toronto could overcome a critical hurdle in the way of large-scale commercialization of hydrogen as a transportation fuel.

Hydrogen is considered attractive as a transportation fuel because when it burns, it leaves behind only oxygen and water as byproducts. But the process for producing hydrogen by electrolysis of water is expensive, and relies on rare elements. The tungsten-based gel developed by Bo Zhang, a visiting researcher from China, and his Canadian colleagues, the Globe and Mail reports, “can break apart molecules of water at about three times the rate and far more cheaply than any substance currently available.”

Relatively cheap and abundant tungsten “doesn’t split the water itself,” the paper explains, “but its presence in the catalyst changes the properties of the other ingredients, specifically an iron-cobalt oxide, enabling it to split water more easily.”

Zhang said the new material can be made at room temperature, unlike many catalysts, can be applied easily as a paste, and “had shown no sign of degrading after 500 hours of testing.”