Invention could solve bottleneck in developing pollution-free cars

Hydrogen-powered cars that don’t pollute the environment are a step closer thanks to a new discovery that promises to solve the main problem holding back the technology: The lack of a safe, efficient system for onboard storage. Hydrogen-powered cars that dont pollute the environment are a step closer thanks to a new discovery that promises to solve the main problem holding back the technology: The lack of a safe, efficient system for onboard storage. Explains Andrew Weller from the Dept. of Chemistry at the University of Bath in the U.K., "Hydrogen has a low density and it only condenses into a liquid at −252°C. This makes it difficult to use conventional storage systems. High-pressure gas containers would need 3-in.-thick steel walls, making them too heavy and large for cars. Scientists have experimented with ways of storing hydrogen by locking the gas into metal lattices. "The U.S. Dept. of Energy has said that it wants 6% of the weight of hydrogen storage systems to be hydrogen in order to give hydrogen powered cars the same mileage/tank of fuel as petrol-based systems, says Weller. "While metal hydrides and metal organic framework materials can give this kind of ratio, they only work at temperature extremes which are difficult to engineer into ordinary vehicles, says Weller. Metal hydrides only work above 300°C and metal organic framework materials only work at liquid nitrogen temperatures −198°C). The University of Bath researchers, however, discovered a new material that works at room temperature and at atmospheric pressure at the flick of a switch. The material, made from a heavy metal (rhodium), only has a weight ratio of 0.1%. This isnt enough for a whole hydrogen tank, says Weller. But the material could be used in combination with metal hydride sources to store and release energy instantaneously until the main