Scientists in Canada have discovered a potential cost-effective method for producing hydrogen by electrolysis of water. It could be the key to large-scale hydrogen storage for renewable energy on demand.
To date, the expense of catalysts from rare crystalline metals has proved a barrier to the development of water electrolysis for energy storage. But in a recent Science paper, Simon Trudel and Curtis Berlinguette of the University of Calgary detailed a novel method for making effective catalysts from metals as cheap, non-toxic and plentiful as iron oxide, aka rust. These, they claimed, perform just as well as existing alternatives, but for a 1,000th of the cost.
Currently, oxides of rare noble metals such as platinum and iridium (which are resistant to corrosion and oxidisation in moist air) are used as catalysts for this energy-hungry reaction. This means the process is expensive: pure iridium, for example, costs nearly £4,000 per 100g.
The Calgary duo have demonstrated a low-temperature, photo-chemical technique that uses an organic nano-scaffold to bind metals, which prevents them from adopting a crystalline form. A mixed-metal oxide of iron, cobalt and nickel produced in this way had “catalytic properties similar to noble metal oxides”, according to the report.
It’s the disordered structure of these amorphous materials that makes them so reactive, explains chemistry professor Berlinguette. “There is no precedent for making amorphous phases of these types of catalysts containing more than one metal. That is the breakthrough.”
The team’s spin-off company, FireWater Fuel Corp., plans to have a commercial electrolyser on the market by 2014, with a smaller home model ready for testing the year after. Berlinguette claims that an electrolyser the size of a beer fridge could store enough renewable power for a whole house.
Shannon Boettcher, a University of Oregon chemistry professor, believes that, with technological advances and economies of scale in manufacture, water electrolysis has the potential to provide “economically viable storage of intermittent renewable energy at a massive scale”.
Photo: Flickr V31S70