Scientists at Tokyo University of Science have used rust as a catalyst for organic waste light-assisted hydrogen production, producing 25 times more hydrogen than previous titanium dioxide catalysts,media reported. Countries such as Japan and South Korea see hydrogen as the clean fuel of the future and are reorganizing to achieve a zero-emissions “hydrogen economy”, in which transportation will be driven mainly by fuel cell vehicles and hydrogen-fuelled vehicles, which emit only water as the final product.
However, economic and sustainable hydrogen production methods have not really been determined. Electrolysis wastes a lot of energy and consumes fresh water. Natural gas or coal production releases a lot of carbon at the production site, eliminating any perceived environmental benefits. Solar-powered photocatalytic processes, invented in the 1970s, produce very little hydrogen and are therefore not worth the trouble or cost of its titanium dioxide catalysts.
Now, a team of researchers at Tokyo University of Science believes it has found a cheap, efficient photocatalytic hydrogen solution based on special types of corrosion.
Using light from xenon lamps, a water-methanol solution and a rust-based catalyst called alpha-FeOOH, the team found that the hydrogen produced was 25 times higher than previous titanium dioxide technology. Another benefit is that this particular form of rust seems to help prevent hydrogen from recombining with oxygen in the container, making it easier to separate and avoid ingesting potential explosion hazards. The structure can continuously and steadily produce hydrogen for more than 400 hours.
The team then plans to study precisely the role of oxygen in activating light-induced alpha-FeOOH reactions, because when oxygen is removed from the reaction chamber, it stops working completely. Although the technology still needs to break down water to produce hydrogen, this may be an effective way to use sunlight without any expensive catalysts.
The study was published in the journal Chemistry: A European Journal.