21 June 2017
New low-cost catalyst helps generate hydrogen fuel
Published online 16 September 2015
Discovery of a cheap metal-based catalyst may pave the way for hydrogen-fuel-based economy.
Hydrogen, touted to be the cleanest fuel, can reduce the atmospheric levels of carbon dioxide. However, existing techniques employ expensive metals such as platinum to generate hydrogen from water.
A catalyst made from cobalt, a metal much cheaper than platinum, and common elements such as phosphorus and sulfur, can efficiently generate hydrogen from water by using electricity and sunlight. Chemically known as pyrite-type cobalt phosphosulfide, this catalyst is potentially useful for manufacturing water-splitting electrolytic and solar-driven photoelectrolysis cells1.
Using the catalyst, Song Jin and his colleagues from US-based University of Wisconsin–Madison prepared films and nanowires on graphite disk and nanoplates on carbon fibre paper.
In electrochemical studies, the films, the nanowires and the nanoplates generated hydrogen from water at very low turn-on potentials. When it came to splitting water, the films, the nanowires and the nanoplates performed better than the previously reported catalysts such as cobalt disulfide and cobalt phosphides.
Teaming up with Jr-Hau He and his colleagues from King Abdullah University of Science and Technology (KAUST), the researchers then found that the catalyst could generate hydrogen from water by harnessing sunlight.
“The catalytic efficiency of the new catalyst is very close to that of the platinum, suggesting its potential for developing electrolytic or solar-driven water-splitting cells,” says Jin.
Cabán-Acevedo, Miguel. et al. Efficient hydrogen evolution catalysis using ternary pyrite-type cobalt phosphosulphide. Nat. Mater. http://dx.doi.org/10.1038/NMAT4410 (2015).