Featured Research

from universities, journals, and other organizations

Researchers identify cause of surface barriers of metal-organic frameworks: Relevant to gas storage

Date:
July 31, 2014
Source:
Karlsruhe Institute of Technology
Summary:
Metal-organic frameworks (MOFs) can take up gases similar to a sponge that soaks up liquids. Hence, these highly porous materials are suited for storing hydrogen or greenhouse gases. However, loading of many MOFs is inhibited by barriers. Scientists now report that the barriers are caused by corrosion of the MOF surface. This can be prevented by water-free synthesis and storing strategies.

Loading of highly porous metal-organic frameworks (MOFs) that are made of metallic nodes (green) and organic connection elements (gray) with gas molecules is often inhibited by surface barriers.
Credit: IFG/KIT

Metal-organic frameworks (MOFs) can take up gases similar to a sponge that soaks up liquids. Hence, these highly porous materials are suited for storing hydrogen or greenhouse gases. However, loading of many MOFs is inhibited by barriers. Scientists of Karlsruhe Institute of Technology (KIT) now report in Nature Communications that the barriers are caused by corrosion of the MOF surface. This can be prevented by water-free synthesis and storing strategies.

Related Articles


MOFs are crystalline materials consisting of metallic nodes and organic connection elements. They have a very large surface area and are highly porous. Like a sponge, they can take up other molecules. MOFs, produced on a large technical scale, are highly suited for the storage of gases: When the gas enters the solid, it is partly liquefied. The density increases and much more molecules can be stored in the same volume. Among others, MOFs are suited for the storage of hydrogen in the tank of hydrogen-driven automobiles. They can also be used for storing greenhouse gases like carbon dioxide and methane. Other applications are substance separation, catalysis, and sensor technology. For any application, an appropriate MOF can be produced. Mostly, MOFs have the form of a powder. In the past ten years, more than 20,000 different representatives of this class have been synthesized and characterized in detail.

"For nearly all applications, loading of these highly porous crystals with molecules is essential," Lars Heinke of the Institute of Functional Interfaces (IFG) of KIT explains. "The efficiency of molecule transport into the porous particles is crucial to the performance of the MOFs." In many MOF materials, however, loading is inhibited largely by so-called surface barriers. The surface of the sponge is broken, the pores are clogged, and loading is delayed significantly. This limits the application opportunities.

To better understand and identify the reasons of these problems, the IFG researchers studied the formation of surface barriers. For this purpose, they conducted fundamental experiments on thin, structurally perfect MOF layers mounted on solid substrates. These SURMOFs (SURface-mounted Metal-Organic Frameworks) are characterized by a high order and ideal structure. The researchers succeeded in attributing the barriers to a corrosion of MOF layers on the surface. They demonstrated how corrosion of the surface layer proceeds and found that water plays a central role. "Many scientists thought that these surface barriers are intrinsic and, hence, cannot be prevented. This assumption has now been disproved. It is possible to produce MOFs for loading without "clogging"," says the Head of KIT's IFG, Professor Christof Wöll. The work reported in the journal "Nature Communications" refutes several previous hypotheses.

The findings might be helpful for many applications of MOFs. Due to the results of the KIT researchers, water-free synthesis strategies for MOFs will have to be developed in the future. Improved materials will ensure barrier-free transport of molecules from the gas phase and liquid phase into MOFs. This will enable to further increase the efficiency of these promising storage and functional materials.


Story Source:

The above story is based on materials provided by Karlsruhe Institute of Technology. Note: Materials may be edited for content and length.


Journal Reference:

  1. Lars Heinke, Zhigang Gu, Christof Wöll. The surface barrier phenomenon at the loading of metal-organic frameworks. Nature Communications, 2014; 5 DOI: 10.1038/ncomms5562

Cite This Page:

Karlsruhe Institute of Technology. "Researchers identify cause of surface barriers of metal-organic frameworks: Relevant to gas storage." ScienceDaily. ScienceDaily, 31 July 2014. <www.sciencedaily.com/releases/2014/07/140731145601.htm>.
Karlsruhe Institute of Technology. (2014, July 31). Researchers identify cause of surface barriers of metal-organic frameworks: Relevant to gas storage. ScienceDaily. Retrieved October 25, 2014 from www.sciencedaily.com/releases/2014/07/140731145601.htm
Karlsruhe Institute of Technology. "Researchers identify cause of surface barriers of metal-organic frameworks: Relevant to gas storage." ScienceDaily. www.sciencedaily.com/releases/2014/07/140731145601.htm (accessed October 25, 2014).

Share This



More Matter & Energy News

Saturday, October 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

IKEA Desk Converts From Standing to Sitting With One Button

IKEA Desk Converts From Standing to Sitting With One Button

Buzz60 (Oct. 24, 2014) — IKEA is out with a new convertible desk that can convert from a sitting desk to a standing one with just the push of a button. Jen Markham explains. Video provided by Buzz60
Powered by NewsLook.com
Ebola Protective Suits Being Made in China

Ebola Protective Suits Being Made in China

AFP (Oct. 24, 2014) — A factory in China is busy making Ebola protective suits for healthcare workers and others fighting the spread of the virus. Duration: 00:38 Video provided by AFP
Powered by NewsLook.com
Real-Life Transformer Robot Walks, Then Folds Into a Car

Real-Life Transformer Robot Walks, Then Folds Into a Car

Buzz60 (Oct. 24, 2014) — Brave Robotics and Asratec teamed with original Transformers toy company Tomy to create a functional 5-foot-tall humanoid robot that can march and fold itself into a 3-foot-long sports car. Jen Markham has the story. Video provided by Buzz60
Powered by NewsLook.com
Police Testing New Gunfire Tracking Technology

Police Testing New Gunfire Tracking Technology

AP (Oct. 24, 2014) — A California-based startup has designed new law enforcement technology that aims to automatically alert dispatch when an officer's gun is unholstered and fired. Two law enforcement agencies are currently testing the technology. (Oct. 24) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins