Nav: Home

Simple equation directs creation of clean-energy catalysts

May 14, 2018

New guidelines laid down by Nebraska and Chinese researchers could steer the design of less costly, more efficient catalysts geared toward revving up the production of hydrogen as a renewable fuel.

Nebraska's Xiao Cheng Zeng and colleagues have identified several overlooked factors critical to the performance of single-atom catalysts: individual atoms, usually metallic and anchored by surrounding molecular frameworks, that kick-start and accelerate chemical reactions.

The team folded those variables into a simple equation requiring what Zeng described as "back-of-the-envelope calculations." That equation should allow researchers to easily predict how the choice of atom and its surrounding material will affect catalytic performance. To date, researchers have often relied on time-consuming trial and error to find promising single-atom catalysts.

"All this (relevant) information can be easily gathered from a textbook," said Zeng, Chancellor's University Professor of chemistry. "Even before an experiment, you can quickly see whether it's a good way to make the catalyst. We're simplifying the process."

Using its equation, the team discovered several atom-framework combinations that approximate the performance of precious-metal catalysts - platinum, gold, iridium - at mere thousandths of the cost. One swapped out a platinum atom for manganese; another replaced iridium with cobalt.

"There are two (primary) ways to reduce the price of these catalysts," Zeng said. "One is to use as little of the metals as possible - so single-atom catalysts are the cheapest. The other direction is finding alternative metals like iron or aluminum or zinc that are very cheap."

Two of the team's atom-framework combinations can split water into its constituent parts: an oxygen atom and two hydrogen atoms, the latter of which can serve as a green fuel for vehicles and other applications. Two other catalyst candidates help oxygen atoms take on more electrons, priming them to bond with positively charged hydrogen atoms and form water - the desired byproduct of hydrogen fuel cells.

"Right now, this is not the prevailing way to produce hydrogen," Zeng said. "The industry still uses fossil fuels to produce hydrogen. It's just cheaper. So that's our motivation: lower the cost so that all these cleaner, fuel-producing reactions become (viable)."

SCOUTING REPORT

The researchers found that the number and nature of atoms directly bonded to a single-atom catalyst can profoundly affect how it catalyzes chemical reactions. In some instances, the catalyzing atom might be attached to either three or four other atoms, each of which is itself part of a five- or six-atom ring. Every atom in that immediate network also has a known attraction to electrons, with the strength of that attraction further influencing catalytic performance.

The arrangement and qualities of those neighboring atoms matter, Zeng said, in the same way that an offensive line matters to a stationary, pocket-passing quarterback. And the team's new equation could act as a scouting report for researchers looking to amplify the strengths or cover the weaknesses of their personnel, he said.

For Zeng and his colleagues, that personnel consisted of more than 20 so-called transition metals that are generally worse than precious metals at catalyzing reactions. But the team showed that surrounding a cobalt, iron or other second-string atom with the right environment - sometimes a honeycomb of carbon atoms known as graphene, sometimes a network of nitrogen atoms - can elevate its performance.

"Every offensive line is different," Zeng said. "How do you make the quarterback function the best in that pocket? How do you find the best quarterback within different pockets?

"If you have a two-star quarterback, you need a better offensive line. But even a backup quarterback can perform well with the right line."

Zeng authored the study with colleagues from Beijing University of Chemical Technology. The study appeared in the journal Nature Catalysis and was highlighted in Chemical and Engineering News, a magazine published by the American Chemical Society.
-end-


University of Nebraska-Lincoln

Related Hydrogen Articles:

Paving the way for hydrogen fuel cells
The hype around hydrogen fuel cells has died down, but scientists have continued to pursue new technologies that could enable such devices to gain a firmer foothold.
Keeping the hydrogen coming
A coating of molybdenum improves the efficiency of catalysts for producing hydrogen.
Hydrogen bonds directly detected for the first time
For the first time, scientists have succeeded in studying the strength of hydrogen bonds in a single molecule using an atomic force microscope.
Argon is not the 'dope' for metallic hydrogen
Hydrogen is both the simplest and the most-abundant element in the universe, so studying it can teach scientists about the essence of matter.
Metallic hydrogen, once theory, becomes reality
Nearly a century after it was theorized, Harvard scientists have succeeded in creating metallic hydrogen.
From theory to reality: The creation of metallic hydrogen
For more than 80 years, it has been predicted that hydrogen will adopt metallic properties under certain conditions, and now researchers have successfully demonstrated this phenomenon.
Artificial leaf goes more efficient for hydrogen generation
A new study, affiliated with Ulsan National Institute of Science and Technology has introduced a new artificial leaf that generates hydrogen, using the power of the Sun to mimic underwater photosynthesis.
Hydrogen from sunlight -- but as a dark reaction
The storage of photogenerated electric energy and its release on demand are still among the main obstacles in artificial photosynthesis.
New process produces hydrogen at much lower temperature
Waseda University researchers have developed a new method for producing hydrogen, which is fast, irreversible, and takes place at much lower temperature using less energy.
Hydrogen in your pocket? New plastic for carrying and storing hydrogen
A Waseda University research group has developed a polymer which can store hydrogen in a light, compact and flexible sheet, and is safe to touch even when filled with hydrogen gas.

Related Hydrogen Reading:

The One-Minute Cure: The Secret to Healing Virtually All Diseases
by Madison Cavanaugh (Author)

Hydrogen and Fuel Cells: Emerging Technologies and Applications
by Bent Sørensen (Author), Giuseppe Spazzafumo (Author)

Hydrogen: The Essential Element
by John S. Rigden (Author)

HYDROGEN: by Dr.Walter / Lectures on Hydrogen
by SANGAKUSHA Publishing Co.,Ltd.

The Magic of Hydrogen Peroxide
by Emily Thacker (Author)

The Hydrogen Sonata (Culture)
by Iain M. Banks (Author)

Hydrogen Peroxide and Aloe Vera - A Home Remedies Handbook
by Conrad LeBeau (Author), Conrad LeBeau (Editor), Conrad LeBeau (Editor)

Hydrogen Peroxide: Medical Miracle
by William Campbell Douglass II (Author)

Build A Solar Hydrogen Fuel Cell System
by Phillip Hurley (Author)

2014 True Power of Hydrogen Peroxide, Miracle Path To Wellness - Mary Wright, goes beyond One Minute Cure
by Mary Wright (Author)

Best Science Podcasts 2018

We have hand picked the best science podcasts for 2018. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Hacking The Law
We have a vision of justice as blind, impartial, and fair — but in reality, the law often fails those who need it most. This hour, TED speakers explore radical ways to change the legal system. Guests include lawyer and social justice advocate Robin Steinberg, animal rights lawyer Steven Wise, political activist Brett Hennig, and lawyer and social entrepreneur Vivek Maru.
Now Playing: Science for the People

#495 Earth Science in Space
Some worlds are made of sand. Some are made of water. Some are even made of salt. In science fiction and fantasy, planet can be made of whatever you want. But what does that mean for how the planets themselves work? When in doubt, throw an asteroid at it. This is a live show recorded at the 2018 Dragon Con in Atlanta Georgia. Featuring Travor Valle, Mika McKinnon, David Moscato, Scott Harris, and moderated by our own Bethany Brookshire. Note: The sound isn't as good as we'd hoped but we love the guests and the conversation and we wanted to...