Team develops recyclable hydrogen fuel

Posted by Emma Woollacott

A new method for “recycling” hydrogen-containing fuel materials could make hydrogen-based vehicles more economically viable.

The big problem with using hydrogen for transportation is its low energy density - you need an awful lot of it to power a car. And the DOE is aiming for vehicles that can travel 300 miles or more on a single fuel tank.

Los Alamos National Laboratory and University of Alabama researchers working for the Chemical Hydrogen Storage Center of Excellence have focused on using a class of materials known as chemical hydrides. Hydrogen can be released from these materials and potentially used to run a fuel cell.

Ammonia borane is a good prospect, because its hydrogen storage capacity approaches a whopping 20 percent by weight. The problem, though, has been the lack of energy-efficient ways to reintroduce hydrogen back into the spent fuel once it has been released. In other words, it couldn’t be adequately recycled.

However, the research team has discovered that a specific form of dehydrogenated fuel, called polyborazylene, could be recycled relatively easily without too much energy input. It's a significant step toward using ammonia borane as a possible energy carrier for transportation purposes.

“This research represents a breakthrough in the field of hydrogen storage and has significant practical applications,” said Dr Gene Peterson, leader of the Chemistry Division at Los Alamos. “The chemistry is new and innovative, and the research team is to be commended on this excellent achievement.”

The team is now working with the Dow Chemical Company to improve overall chemical efficiencies and move toward large-scale implementation of hydrogen-based fuels.

The full article is in Angewandte Chemie International Edition.