Subscribe to our free daily newsletters
. 24/7 Space News .




Subscribe to our free daily newsletters



CARBON WORLDS
Recruiting manganese to upgrade carbon dioxide
by Staff Writers
Onna, Japan (SPX) Jul 10, 2017


The manganese atom (in purple) is at the center of the frame - the ligand - which facilitates the hydrogenation of CO2. Credit OIST

Carbon dioxide (CO2) is known as a greenhouse gas and plays an essential role in climate change; it is no wonder scientists have been looking for solutions to prevent its release in the environment. However, as a cheap, readily available and non-toxic carbon source, in the past few years there have been efforts to turn carbon dioxide into valuable wares, or 'value-added' products.

For instance, carbon dioxide enables energy storage by reacting with hydrogen gas - called the hydrogenation process - transforming the mixture into higher energy liquid compounds such as methanol that can be easily transported and used as fuel for cars.

Similarly, carbon dioxide hydrogenation in the presence of other chemicals can lead to the formation of various value-added products widely used in industry such as formic acid, formamides, or formaldehyde. These chemicals can also potentially be used for energy storage as, for example, heating formic acid under certain conditions allow for the release of hydrogen gas in a controlled and reversible fashion.

Conversion of carbon dioxide into useful products is complicated by the fact that CO2 is the most oxidized form of carbon and as such a very stable and unreactive molecule. Therefore, the direct reaction of CO2 with hydrogen requires high energy, making the process economically unfavorable.

This problem can be overcome using catalysts, which are compounds used in small amounts to accelerate chemicals reactions. For CO2 hydrogenation purposes, most known catalysts are based on precious metals such as iridium, rhodium or ruthenium. While excellent catalysts, the scarcity of these precious metals makes it difficult to use them at industrial scales.

They are also hard to recycle and potentially toxic for the environment. Other catalysts use cheaper metals such as iron or cobalt but require a phosphorus-based molecule - called phosphine -surrounding the metal. Phosphines are not always stable around oxygen and sometimes burn violently in an air atmosphere, which presents another problem for the practical applications.

To overcome these issues, the OIST Coordination Chemistry and Catalysis Unit led by Prof. Julia Khusnutdinova reported in ACS Catalysis novel and efficient catalysts based on an inexpensive and abundant metal: manganese. Manganese is the third most abundant metal in Earth's crust after titanium and iron, and presents much lower toxicity as compared to many other metals used in CO2 hydrogenation.

The scientists initially looked for inspiration within the natural world: hydrogenation is a reaction that occurs in many organisms that would not have access to precious metals or phosphines. They observed the structure of specific enzymes - hydrogenases - to understand how they could accomplish hydrogenation using simple, Earth-abundant materials. To facilitate the hydrogenation, enzymes utilize a 'smart' arrangement where the surrounding organic framework cooperates with a metal atom - like iron- efficiently kick-starting the reaction.

"After looking at hydrogenases, we wanted to check if we could make artificial molecules that mimics these enzymes using the same type of common materials, like iron and manganese," explained Dr. Abhishek Dubey, the first author of this study.

The main challenge of this study was to build an adequate frame - called a ligand - around the manganese to induce the hydrogenation. The scientists came up with a surprisingly simple ligand structure resembling natural hydrogenase enzymes with a twist from typical phosphine catalysts.

"In most cases, ligands support the metal without directly taking part in a chemical bond activation. In our case, we believe the ligand directly participates in the reaction," said Dr. Dubey.

In ligand design, the structure of a ligand is tightly linked to its efficiency. The new catalyst - the ligand and the manganese together - can perform more than 6,000 turnovers in a hydrogenation reaction, converting more than 6,000 times CO2 molecules before decaying. And this new ligand, the outcome of a collaboration with an international team including Prof. Carlo Nervi and Mr. Luca Nencini from University of Turin in Italy and Dr. Robert Fayzullin from Russia, is simple to manufacture and stable in the air.

For now, the catalyst is able to transform carbon dioxide into formic acid, a widely-used food preservative and tanning agent, and formamide, which has industrial applications. But the versatility of this catalyst opens many other possibilities.

"Our next goal is to utilize such structurally simple, inexpensive manganese catalysts to target other types of reactions in which CO2 and hydrogen can be converted into useful organic chemicals", concluded Prof. Khusnutdinova.

Research paper

CARBON WORLDS
Black carbon varies, but stubbornly persists, in snow and ice around the world
Boulder CO (SPX) Jul 03, 2017
A new University of Colorado Boulder study comparing dissolved black carbon deposition on ice and snow in ecosystems around the world (including Antarctica, the Arctic, and alpine regions of the Himalayas, Rockies, Andes, and Alps) shows that while concentrations vary widely, significant amounts can persist in both pristine and non-pristine areas of snow. Black carbon is the soot-like bypr ... read more

Related Links
Okinawa Institute of Science and Technology (OIST) Graduate University
Carbon Worlds - where graphite, diamond, amorphous, fullerenes meet


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

CARBON WORLDS
Dutch project tests floating cities to seek more space

Don't look down: glass bottom skywalk thrills in China

NASA Statement on National Space Council

Silicon-on-Seine: world's biggest tech incubator opens in Paris

CARBON WORLDS
After two delays, SpaceX launches broadband satellite for IntelSat

On the road to creating an electrodeless spacecraft propulsion engine

Dragon Splashes Down to Complete Resupply Mission

Ariane 5 launch proves reliability and flies new fairing

CARBON WORLDS
Mars surface 'more uninhabitable' than thought: study

Mars Rover Opportunity continuing science campaign at Perseverance Valley

The Niagara Falls of Mars once flowed with lava

Russian Devices for ExoMars Mission to Be Ready in Fall 2017

CARBON WORLDS
Chinese satellite Zhongxing-9A enters preset orbit

Chinese Space Program: From Setback, to Manned Flights, to the Moon

China prepares to launch second heavy-lift carrier rocket

China heavy-lift carrier rocket launch fails: state media

CARBON WORLDS
HTS Capacity Lease Revenues to Reach More Than $6 Billion by 2025

SES Transfers Capacity from AMC-9 Satellite Following Significant Anomaly

Second launch doubles number of Iridium NEXT satellites in orbit to 20

OneWeb inaugurates production line Assembly, Integration, and Test of OneWeb satellites

CARBON WORLDS
Sorting complicated knots

Engineers find way to evaluate green roofs

Nature-inspired material uses liquid reinforcement

Feel the heat, one touch a time

CARBON WORLDS
NASA diligently tracks microbes inside the International Space Station

Why Does Microorganism Prefer Meager Rations Over Rich Ones

Complex Organic Molecules Found On "Space Hamburger"

Extreme Atmosphere Stripping May Limit Exoplanets' Habitability

CARBON WORLDS
New Mysteries Surround New Horizons' Next Flyby Target

Mid-infrared images from the Subaru telescope extend Juno spacecraft discoveries

Earth-based Views of Jupiter to Enhance Juno Flyby

NASA's Juno Spacecraft to Fly Over Jupiter's Great Red Spot July 10




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