Science

Could moly sulfide be the key to cheaper hydrogen production?

Could moly sulfide be the key to cheaper hydrogen production?
A moly sulfide nanocluster on a graphite surface form the electrode that allows it to form hydrogen through electrolysis (Image: Jakob Kibsgaard)
A moly sulfide nanocluster on a graphite surface form the electrode that allows it to form hydrogen through electrolysis (Image: Jakob Kibsgaard)
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Assistant Professor Thomas Jaramillo and his co-authors concluded that it could be feasible to produce hydrogen in factory-scale electrolysis facilities at competitive costs (Photo: Linda A. Cicero)
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Assistant Professor Thomas Jaramillo and his co-authors concluded that it could be feasible to produce hydrogen in factory-scale electrolysis facilities at competitive costs (Photo: Linda A. Cicero)
A moly sulfide nanocluster on a graphite surface form the electrode that allows it to form hydrogen through electrolysis (Image: Jakob Kibsgaard)
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A moly sulfide nanocluster on a graphite surface form the electrode that allows it to form hydrogen through electrolysis (Image: Jakob Kibsgaard)

Chemical engineers have found a 30-year-old recipe that stands to make future hydrogen production cheaper and greener. The recipe has led researchers to a way to liberate hydrogen from water via electrolysis using molybdenum sulfide – moly sulfide for short – as the catalyst in place of the expensive metal platinum.

While hydrogen is relatively abundant here on Earth, it is generally bound to either carbon or oxygen to form methane and water respectively. Producing hydrogen currently involves liberating it from methane at a cost of between US$1 and $2 per kilogram. And the world’s hunger for hydrogen continues to grow, currently we consume 55 billion kilograms of the element per year, making freeing it from methane or water big business. And with numerous automakers dipping their tires in the hydrogen fuel waters, it's set to get much bigger.

The other side of the equation is the by-product of production. When hydrogen is freed from methane the waste product is carbon, which is released into the atmosphere furthering climate change. Producing hydrogen from water on the other hand produces oxygen as waste.

The limiting factor to getting hydrogen from water in the past has been the expense of electrolysis, the process were hydrogen atoms are liberated from their bond with oxygen in water by passing an electrical current through an electrode immersed in the water. The main expense in this process was the use of platinum as the electrode. The efficiency of platinum to catalyze the breaking of hydrogen-oxygen bonds in water to free the hydrogen until now has been unmatched.

Enter moly sulfide. Since World War II, moly sulfide has been used by petroleum engineers in the refinement of oil. It was thought to be inefficient for the electrolysis of hydrogen from water due to the molecular structure at its surface.

That was until Stanford Engineering's Jens Nørskov, then at the Technical University of Denmark, noticed this structure differed at the edges of the crystal lattice. Around the edges, hydrogen production was possible as the structure has only two chemical bonds rather than the three seen elsewhere in its structure. This meant moly sulfide was capable of electrolyzing hydrogen, if only at the edges.

Next came the Eureka moment, when the researchers uncovered a 30-year-old recipe for double bonded moly sulfide. Using this recipe, nanoclusters of double-bonded moly sulfide were synthesized and deposited on an electrically conductive sheet of graphite to form a cheap electrode alternative to platinum.

Initial tests show the new technology to work at an efficiency approaching that of platinum. Early cost predictions for factory-scale production range from $1.60 to $10.40, which at the lower end would be competitive with current methane-based methods.

"There are many pieces of the puzzle still needed to make this work and much effort ahead to realize them," said Stanford Engineering Assistant Professor Thomas Jaramillo. "However, we can get huge returns by moving from carbon-intensive resources to renewable, sustainable technologies to produce the chemicals we need for food and energy.”

Findings of the research, which is a collaboration between Stanford University and Aarhus University in Denmark, were published in Nature Chemistry .

Source: Stanford University

9 comments
9 comments
Bruce H. Anderson
AS I read the article above, and look at the links below to previous Gizmag articles, it appears that a new and exciting development occurs annually. I hope one of them can be commercialized.
Julie Rosenthal
I avidly read Gizmag because it elates me to know our new generation of thinkers and do-ers are making our world more self sustaining. Thank you, Gizmag, for your interesting and thought provoking articles!
Darren Walker
Dr. Howard Phillips of the Phillips Co. in Millerton, Okla. has produced as much as 40 gallons per minute of hydrogen using the most significant advance in hydrogen generation in decades, the CC HOD Phillips Method. Dr. Phillips gave a presentation at the recent www.HHOgames.com tradeshow in Tampa, Florida. Gizmag should also be following Dr. Ruggero Santilli and the www.MAGNEGAS.com, Tampa company.
On January 21, 2013, the Phillips Company sponsored a Catalytic-Carbon Hydrogen-on-Demand Equipment Design Conference (CC-HOD) to demonstrate their technology.
Don't forget HydroInfra and their Hydro Nano Gas ( Brown's Gas? ): http://www.hydroinfra.com/en/
Denzel Miles
Toyota must be happy to hear this for there new car
StWils
Great Idea, and yup, this, or variants and elements reappear with some regularity. However it will never be more than a lab toy until the U.S. government or another large power signs on. Alternatively, maybe the Wylies or Kochs, or other 1/10 percenters can figure out how to do this while simultaneously screwing rest of us to the wall on delivery.
Eggster
"When hydrogen is freed from methane the waste product is carbon, which is released into the atmosphere furthering climate change. "
Our use of terminology has become fairly sloppy. Carbon, by itself, is not a threat to the environment. Carbon + oxygen, on the other hand, is accepted as a contributor to 'climate change'. Carbon can be sequestered rather easily, whereas carbon dioxide (or monoxide) cannot be handled quite so easily.
Bob
Platinum is very expensive but since platinum lasts a long time, I'm not sure how replacing it with molybdenum sulfide will make hydrogen production that much cheaper. The biggest cost will continue to be electricity and the cheapest source of hydrogen will continue to be from natural gas.
Jim Sadler
Platinum is also in very short and limited supply. to build on an industrial scale many millions in platinum might be required. Moly could cut the initial investment in large scale units to a point at which it is financially viable to build such machines.
Esteban Sperber Frankel
By methane or natural gas the carbon waste is not carbon black?.