- Category: Technology
09 Nov 2012
- Published on Friday, 09 November 2012 08:40
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Why pay around $24,000 per pound for a catalyst when you can get similar results for $8 per pound?
That is what’s driving the University of Rochester’s work in developing a nickel-based catalyst to replace platinum catalysts in photocatalytic hydrogen production systems. The job is seen as advancing in efforts to efficiently use sunlight for clean, carbon-free energy and fuel.
“People have typically used catalysts made from platinum and other expensive metals,” said Patrick Holland, a chemistry professor. “It would be much more sustainable if we used metals that were more easily found on the Earth, more affordable and lower in toxicity. That would include metals such as nickel.”
For their catalyst, the researchers incorporated durable cadmium selenide quantum dots or nanocrystals as their light-absorbing material or chromophore, to increase its life span.
“The problem is [chromophores] only last hours, or, if you’re lucky, a day. These nanocrystals performed without any sign of deterioration for at least two weeks,” said Mr. Kraus.
The nanocrystals and the nickel catalyst (nickel nitrate) were placed in a solution of water and ascorbic acid and exposed to a light source.
Photons from a light source excited electrons in the nanocrystals and transferred them to the nickel catalysts. When two electrons are available, they combine on the catalyst with protons from water to form a hydrogen molecule.
All in all, with their new materials and processes, the researchers saw turnovers – instances of hydrogen atoms being formed – in excess of 600,000 compared with the usual 10,000 instances.
This system was so robust that it kept producing hydrogen until the source of electrons was removed after two weeks.
While all three researchers say the commercial implementation of their work is years off, Mr. Holland points out that an efficient, low-cost system would have uses beyond energy.
"Any industry that requires large amounts of hydrogen would benefit, including pharmaceuticals and fertilizers," said Mr. Holland. – EcoSeed Staff