‘Green’ process runs on sunlight
Sandia National Laboratories researchers seeking to make hydrogen a less expensive fuel for cars have upgraded a catalyst nearly as cheap as dirt — molybdenum disulfide, “molly” for short — to stand in for platinum, a rare element with the moonlike price of $1,500 a gram.
Sandia-induced changes elevate the plentiful, 37-cents-a-gram molly from being a welterweight outsider in the energy-catalyst field — put crudely, a lazy bum that never amounted to much — to a possible contender with the heavyweight champ.
The improved catalyst, expected to be the subject of an Oct. 7 Nature Communications paper, has already released four times the amount of hydrogen ever produced by molly from water. To Sandia postdoctoral fellow and lead author Stan Chou, this is just the beginning: “We should get far more output as we learn to better integrate molly with, for example, fuel-cell systems,” he said.
An additional benefit is that molly’s action can be triggered by sunlight, a feature which eventually may provide users an off-the-grid means of securing hydrogen fuel.
Hydrogen fuel is desirable because, unlike gasoline, it doesn’t release carbon into the atmosphere when burned. The combustion of hydrogen with oxygen produces an exhaust of only water.
In Chou’s measured words, “The idea was to understand the changes in the molecular structure of molybdenum disulfide (MOS?), so that it can be a better catalyst for hydrogen production: closer to platinum in efficiency, but earth-abundant and cheap. We did this by investigating the structural transformations of MOS? at the atomic scale, so that all of the materials parts that were ‘dead’ can now work to make H? [hydrogen].”
The rind of an orange
in what sense were the parts “dead,” one might ask?
Visualize an orange slice where only the rind of the orange is useful; the rest — the edible bulk of the orange — must be thrown away. Molly exists as a stack of flat nanostructures, like a pile of orange slices. These layers are not molecularly bolted together like a metal but instead are loose enough to slide over one another — a kind of grease, similar to the structure of graphene, and with huge internal surface areas.
But here’s the rub: While the edges of these nanostructures match platinum in their ability to catalyze hydrogen, the relative immense surface area of their sliding interiors are useless because their molecular arrangements are different from their edges. Because of this excess baggage, a commercial catalyst would require a huge amount of molly. The slender edges would work hard like Cinderella, but the stepsister interiors would just hang out, doing nothing.
Chou, who works on two-dimensional materials and their properties, thought the intent should be to get these stepsisters jobs.
Empowering the center
“There are many ways to do this,” said co-author Bryan Kaehr, “but the most scalable way is to separate the nanosheets in solution using lithium. With this method, as you pull the material apart, its molecular lattice changes into different forms; the end product, as it turns out, is catalytically active like the edge structure.”
To determine what was happening, and the best way to make it happen, the Sandia team used computer simulations generated by coauthor Na Sai from the University of Texas at Austin that suggested which molecular changes to look for. The team also observed changes with the most advanced microscopes at Sandia. including the FEI Titan, an aberration-corrected transmission electron microscope able to view atoms normally too small to see on most scopes.
“The extended test period made possible by the combined skills of our group allowed the reactions to be observed with the amount of detail needed,” said Chou.
Lacking these tools, researchers at other labs had ended their tests before the reaction could complete itself, like a cook taking sugar and water off the stove before syrup is produced, resulting in a variety of conflicting intermediate results.
“Why Stan’s work is impactful is that there was so much confusion as to how this process works and what structures are actually formed,” said Kaehr. “He unambiguously showed that this desirable catalytic form is the end result of the completed reaction.”
Said Sandia Fellow and University of New Mexico professor Jeff Brinker, another paper author, “People want a non-platinum catalyst. Molly is dirt cheap and abundant. By making these relatively enormous surface areas catalytically active, Stan established understanding of the structural relation of these two-dimensional materials that will determine how they will be used in the long run. You have to basically understand the material before you can move forward in changing industrial use.”
Kaehr cautions that what’s been established is a fundamental proof of principle, not an industrial process. “Water splitting is a challenging reaction. It can be poisoned, stopping the molly reaction after some time period. Then you can restart it with acid. There are many intricacies to be worked out.
“But getting inexpensive molly to work this much more efficiently could drive hydrogen production costs way down.”
The Latest on: Hydrogen production
via Google News
The Latest on: Hydrogen production
- ENGIE chooses Plug Power hydrogen refueling system for world’s largest mine truckon December 9, 2019 at 11:19 pm
The company is also working with global mining company Anglo American. That partnership is moving toward the development of hydrogen production and a refueling station that will complement a new ...
- Sarawak to build six new hydrogen refuelling stations in the state, says Abang Joharion December 9, 2019 at 9:39 pm
Two of the proposed stations would be located in Kuching and one each in Sri Aman, Sibu, Bintulu and Miri. He said an integrated hydrogen production plant and refuelling station, touted to be the ...
- Green hydrogen: Research to enhance efficiencyon December 9, 2019 at 9:40 am
The findings published recently in the journal Physical Review Letters offer a possible starting point for enhancing the environmental impact of hydrogen-based technologies. Workable solutions for the ...
- Hydrogen fuel in Queensland – what is nexton December 7, 2019 at 6:04 pm
A key challenge with this reaction is that a by-product is the greenhouse gas, carbon dioxide. However, technologies that allow for the storage of that carbon dioxide are emerging, which would make ...
- A $39 Billion Wind Company Bets Hydrogen Is Key to Climate Goalson December 5, 2019 at 9:30 pm
(Bloomberg) -- One of the world’s biggest developers of offshore wind farms thinks its massive turbines could be key to the production of hydrogen in a greener way and ultimately, stemming climate ...
- Toyota really believes hydrogen fuel cells are the future: Here’s whyon December 4, 2019 at 6:00 am
(The Fukushima Hydrogen Energy Research Field will open in spring, with a 10,000-kW hydrogen production facility that uses solar panels to make several hundred tons of hydrogen a year through ...
- Raven SR’s Non-Combustion Technology Reaches New Highs in Hydrogen Production Efficiencyon December 4, 2019 at 12:02 am
which then delivers a high hydrogen or synthetic fuel production,” said Matt Murdock, Raven SR CEO. “These results are from our smaller engineering unit at our facility on the UC Berkley Richmond ...
- Plug Power Selected by ENGIE to Deliver Refueling System for World’s Largest Hydrogen-Powered Mine Truckon December 3, 2019 at 7:54 am
ENGIE is working with Anglo American, a global mining company, to develop a renewable hydrogen production and refueling solution to support a new hydrogen-powered mine haul vehicle that will be ...
- Hydrogen Storage Market 2019 | Industry Size, Share, Price, Trend and Global Forecast to 2024on December 3, 2019 at 3:34 am
The report includes distinct types of companies such as: - Hydrogen production, fuel cell and hydrogen storage material and technology providers. - Manufacturers of industrial gases and related ...
- Sandia work may lower bar for hydrogen techon December 1, 2019 at 11:10 pm
Breakthroughs in advanced hydrogen storage materials coming out of HyMARC will also support DOE’s [email protected] initiative to enable affordable large-scale hydrogen production, storage, transport and ...
via Bing News