Subscribe to our free daily newsletters
  Energy News  




Subscribe to our free daily newsletters



ENERGY TECH
Electronic entropy enhances water splitting
by Staff Writers
Chicago IL (SPX) Oct 25, 2017


Wolverton and others previously knew that entropy was key to making this reaction possible, but they were unable to find the source of cerium's entropy. "Most people thought entropy was caused by mixing oxygen or vibrations from the heat," Wolverton said. "But we found that it's a different source, and it's not what you might think." (illustration only)

Researchers have long known that cerium is the best element to use when splitting water into hydrogen and oxygen - a key technique in creating hydrogen gas for fuel. But why, exactly, cerium is so successful has been far less understood.

Now a Northwestern University team led by Chris Wolverton has discovered that cerium's electronic entropy, which is created when an electron transitions among various states within an electron shell, is the underlying reason for its success. This finding could help researchers better exploit cerium's entropy for water-splitting technologies.

"In order for water splitting to be fast enough to be practical, you need a large amount of entropy," said Wolverton, professor of materials science and engineering in Northwestern's McCormick School of Engineering. "It turns out that cerium is magic for entropy."

Supported by the US Department of Energy, the research was recently published in Nature Communications. Shahab Naghavi, a postdoctoral fellow in the Wolverton Research Group, served as the paper's first author.

Since the 1970s, researchers have touted the potential of a "hydrogen economy," in which hydrogen would replace gasoline to fuel ground transportation. When burned, hydrogen's only byproduct is water, making it environmentally cleaner and more energy efficient than its fossil-fuel alternatives. Pure hydrogen gas, however, is very rare within the Earth's atmosphere.

"The problem is: how do you get the hydrogen in the first place?" Wolverton asked. "Currently, you have to burn hydrocarbons, but that produces carbon dioxide."

Water (or steam) splitting could cleanly and efficiently produce enough pure hydrogen to make the hydrogen economy a true possibility. To split hydrogen from oxygen, researchers use heat generated by solar radiation and cerium oxide, or ceria. Using sunlight to heat ceria to 1,000- to 1,500-degrees Celsius drives a series of reactions that cause hydrogen to split off.

Wolverton and others previously knew that entropy was key to making this reaction possible, but they were unable to find the source of cerium's entropy. "Most people thought entropy was caused by mixing oxygen or vibrations from the heat," Wolverton said. "But we found that it's a different source, and it's not what you might think."

In order for the chemical reaction that drives water splitting to be successful, cerium in the oxide must gain an electron. And that single electron gives rise to whole lot of entropy.

"If there are multiple places for the electron, that gives rise to electronic entropy," Wolverton explained. "The electron can transition from one state to another to another and creates disorder on the electronic scale, and hence, entropy."

Cerium's family of elements - known as rare earths - naturally have more electron states around which the electron can move. Wolverton's team computed the electronic entropy of all 17 rare earths and discovered that cerium demonstrated the largest amount.

"For a long time, we've known that cerium is good for water splitting, but we didn't quite know why," Wolverton said. "Now we partially know why, and that opens up possibilities for future work."

ENERGY TECH
A new way to produce clean hydrogen fuel from water using sunlight
Osaka, Japan (SPX) Oct 06, 2017
Hydrogen is the most abundant element in the universe, and is considered by many to be a potential clean fuel of the future. Water and fossil fuels contain large amounts of hydrogen, but unlocking molecular dihydrogen fuel from these sources takes a great deal of energy, casting doubt over any future hydrogen economy. Turning water into hydrogen using solar energy could lead the way to cheap and ... read more

Related Links
Northwestern University
Powering The World in the 21st Century at Energy-Daily.com


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only

Comment using your Disqus, Facebook, Google or Twitter login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

ENERGY TECH
IEA: An electrified world would cost $31B per year to achieve

'Fuel-secure' steps in Washington counterintuitive, green group says

SLAC-led project will use AI to prevent or minimize electric grid failures

Scientists propose method to improve microgrid stability and reliability

ENERGY TECH
Sulfur may be key for safe rechargeable lithium batteries

The blob that ate the tokamak

Loops of liquid metal can improve future fusion power plants

A new miniature solution for storing renewable energy

ENERGY TECH
Construction to begin on $160 million Industry Leading Hybrid Renewable Energy Project

A kite that might fly

Scotland outreach to Canada yields wind energy investment

First floating wind farm starts operation in Scotland

ENERGY TECH
How solar peaker plants could replace gas peakers

Transparent solar technology represents 'wave of the future'

Clean Energy Collective Starts Construction on SCE and G Community Solar Facilities

SCE monopoly abuse of power prompts the necessity of off-grid inventions

ENERGY TECH
South Korea to push ahead with nuclear power plants

AREVA NP awarded contract for safety upgrades in seven reactors

AREVA NP installs a system allowing flexible electricity generation at Goesgen nuclear power plant

MATRIX pitched as a game changer for used fuel dry storage

ENERGY TECH
Separating methane and CO2 will become more efficient

Converting carbon dioxide to carbon monoxide using water, electricity

Breaking down stubborn cellulose

Breakthrough in direct activation of CO2 and CH4 into liquid fuels and chemicals

ENERGY TECH
Electricity from shale gas versus coal

North America helped drive revenue for Halliburton

Oil prices diverge on competing trends

Gas has environmental benefits, with caveats

ENERGY TECH
Geologic evidence is the forerunner of ominous prospects for a warming earth

'Plan B': Seven ways to engineer the climate

British government unveils green spending plans

As Paris climate goals recede, geoengineering looms larger




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News






The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement