Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Gold nanoparticles give an edge in recycling CO2

25.10.2013
It’s a 21st-century alchemist’s dream: turning Earth’s superabundance of carbon dioxide — a greenhouse gas — into fuel or useful industrial chemicals.

Researchers from Brown have shown that finely tuned gold nanoparticles can do the job. The key is maximizing the particles’ long edges, which are the active sites for the reaction.


Less is more ... to a point
Gold nanoparticles make better catalysts for CO2 recycling than bulk gold metal. Size is crucial though, since edges produce more desired results than corners (red points, above). Nanoparticles of 8 nm appear to have a better edge-to-corner ratio than 4 nm, 6 nm, or 10 nm nanoparticles. Credit: Sun lab/Brown University

By tuning gold nanoparticles to just the right size, researchers from Brown University have developed a catalyst that selectively converts carbon dioxide (CO2) to carbon monoxide (CO), an active carbon molecule that can be used to make alternative fuels and commodity chemicals.

“Our study shows potential of carefully designed gold nanoparticles to recycle CO2 into useful forms of carbon,” said Shouheng Sun, professor of chemistry and one of the study’s senior authors. “The work we’ve done here is preliminary, but we think there’s great potential for this technology to be scaled up for commercial applications.”

The findings are published in the Journal of the American Chemical Society.

The idea of recycling CO2 — a greenhouse gas the planet current has in excess — is enticing, but there are obstacles. CO2 is an extremely stable molecule that must be reduced to an active form like CO to make it useful. CO is used to make synthetic natural gas, methanol, and other alternative fuels.

Converting CO2 to CO isn’t easy. Prior research has shown that catalysts made of gold foil are active for this conversion, but they don’t do the job efficiently. The gold tends to react both with the CO2 and with the water in which the CO2 is dissolved, creating hydrogen byproduct rather than the desired CO.

The Brown experimental group, led by Sun and Wenlei Zhu, a graduate student in Sun’s group, wanted to see if shrinking the gold down to nanoparticles might make it more selective for CO2. They found that the nanoparticles were indeed more selective, but that the exact size of those particles was important. Eight nanometer particles had the best selectivity, achieving a 90-percent rate of conversion from CO2 to CO. Other sizes the team tested — four, six, and 10 nanometers — didn’t perform nearly as well.

“At first, that result was confusing,” said Andrew Peterson, professor of engineering and also a senior author on the paper. “As we made the particles smaller we got more activity, but when we went smaller than eight nanometers, we got less activity.”

To understand what was happening, Peterson and postdoctoral researcher Ronald Michalsky used a modeling method called density functional theory. They were able to show that the shapes of the particles at different sizes influenced their catalytic properties.

“When you take a sphere and you reduce it to smaller and smaller sizes, you tend to get many more irregular features — flat surfaces, edges and corners,” Peterson said. “What we were able to figure out is that the most active sites for converting CO2 to CO are the edge sites, while the corner sites predominantly give the by-product, which is hydrogen. So as you shrink these particles down, you’ll hit a point where you start to optimize the activity because you have a high number of these edge sites but still a low number of these corner sites. But if you go too small, the edges start to shrink and you’re left with just corners.”

Now that they understand exactly what part of the catalyst is active, the researchers are working to further optimize the particles. “There’s still a lot of room for improvement,” Peterson said. “We’re working on new particles that maximize these active sites.”

The researchers believe these findings could be an important new avenue for recycling CO2 on a commercial scale.

“Because we’re using nanoparticles, we’re using a lot less gold than in a bulk metal catalyst,” Sun said. “That lowers the cost for making such a catalyst and gives the potential to scale up.”

The work was funded by a National Science Foundation grant to the Brown-Yale Center for Chemical Innovation (CCI), which looks for ways to use CO2 as a sustainable feedstock for large-scale commodity chemicals. Other authors on the paper were Önder Metin, Haifeng Lv, Shaojun Guo, Christopher Wright, and Xiaolian Sun.

Editors: Brown University has a fiber link television studio available for domestic and international live and taped interviews, and maintains an ISDN line for radio interviews. For more information, call (401) 863-2476.

Kevin Stacey | EurekAlert!
Further information:
http://www.brown.edu

More articles from Life Sciences:

nachricht A new technique isolates neuronal activity during memory consolidation
22.06.2017 | Spanish National Research Council (CSIC)

nachricht CWRU researchers find a chemical solution to shrink digital data storage
22.06.2017 | Case Western Reserve University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

Im Focus: Optoelectronic Inline Measurement – Accurate to the Nanometer

Germany counts high-precision manufacturing processes among its advantages as a location. It’s not just the aerospace and automotive industries that require almost waste-free, high-precision manufacturing to provide an efficient way of testing the shape and orientation tolerances of products. Since current inline measurement technology not yet provides the required accuracy, the Fraunhofer Institute for Laser Technology ILT is collaborating with four renowned industry partners in the INSPIRE project to develop inline sensors with a new accuracy class. Funded by the German Federal Ministry of Education and Research (BMBF), the project is scheduled to run until the end of 2019.

New Manufacturing Technologies for New Products

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

A new technique isolates neuronal activity during memory consolidation

22.06.2017 | Life Sciences

Plant inspiration could lead to flexible electronics

22.06.2017 | Materials Sciences

A rhodium-based catalyst for making organosilicon using less precious metal

22.06.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>