Featured Research

from universities, journals, and other organizations

High-Intensity Ultrasound Creates Better Catalyst For Cleaning Fuels

Date:
July 9, 1998
Source:
University Of Illinois At Urbana-Champaign
Summary:
Using high-intensity ultrasound, researchers at the University of Illinois have discovered a dramatically improved catalyst for removing smelly sulfur-containing compounds from gasoline and other fossil fuels.

CHAMPAIGN, Ill. - Using high-intensity ultrasound, researchers at the University of Illinois have discovered a dramatically improved catalyst for removing smelly sulfur-containing compounds from gasoline and other fossil fuels. The improved catalyst is a new form of molybdenum disulfide, most commonly recognized as the black lubricant used to grease automobiles and machinery.

Molybdenum disulfide normally consists of long, flat layers of molybdenum metal atoms sandwiched above and below by single atomic layers of sulfur. Because the interaction between the sulfur planes is weak, they can easily slide on one another, providing excellent high-temperature lubrication.

But molybdenum disulfide's other important commercial application is as a catalyst used by the petroleum industry to remove sulfur-containing compounds in gasoline. Upon combustion, these unwanted sulfur compounds would contribute to the formation of ecologically damaging acid rain.

"The flat planes of molybdenum disulfide that make it such a good lubricant also interfere with its ability to react with fuels to remove sulfur," said Kenneth Suslick, a U. of I. professor of chemical sciences. "This is because all the reactions necessary for sulfur removal occur along the edges of the long planes, and the bigger the planes, the less relative edge there is."

Suslick and students Millan Mdleleni and Taeghwan Hyeon discovered a way to make molybdenum disulfide with many more edge atoms using a technique called sonochemistry -- the chemical application of high-intensity ultrasound. The technique produces very small particles of molybdenum disulfide, 1,000 times smaller than the thickness of a human hair, that subsequently do not form into planes.

The sonochemical synthesis arises from acoustic cavitation -- the formation, growth and implosive collapse of small gas bubbles in a liquid blasted with sound. The collapse of these cavitating bubbles generates intense local heating, forming a hot spot in the cold liquid with a transient temperature of about 9,000 degrees Fahrenheit, the pressure of about 1,000 atmospheres and the duration of about a billionth of a second.

"When the bubbles collapse, the vapor of volatile molybdenum-metal-containing compounds inside the bubbles is decomposed into hot metal atoms," Suslick said. "These atoms then react with sulfur dissolved in the liquid to form clusters of molybdenum disulfide that contain a few thousand atoms and are about a millionth of an inch in diameter."

As the researchers reported in the June 24th issue of the Journal of the American Chemical Society, these clusters are too small to have extended planes of atoms and consequently possess many more edge atoms that can participate in the sulfur-removal process.

"Our sonochemically prepared molybdenum disulfide is 10 times more active than the standard industrial catalyst," Suslick said. "The sonochemical synthesis is simple, quick and easy to scale up."


Story Source:

The above story is based on materials provided by University Of Illinois At Urbana-Champaign. Note: Materials may be edited for content and length.


Cite This Page:

University Of Illinois At Urbana-Champaign. "High-Intensity Ultrasound Creates Better Catalyst For Cleaning Fuels." ScienceDaily. ScienceDaily, 9 July 1998. <www.sciencedaily.com/releases/1998/07/980709085806.htm>.
University Of Illinois At Urbana-Champaign. (1998, July 9). High-Intensity Ultrasound Creates Better Catalyst For Cleaning Fuels. ScienceDaily. Retrieved July 31, 2014 from www.sciencedaily.com/releases/1998/07/980709085806.htm
University Of Illinois At Urbana-Champaign. "High-Intensity Ultrasound Creates Better Catalyst For Cleaning Fuels." ScienceDaily. www.sciencedaily.com/releases/1998/07/980709085806.htm (accessed July 31, 2014).

Share This




More Matter & Energy News

Thursday, July 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Britain Testing Driverless Cars on Roadways

Britain Testing Driverless Cars on Roadways

AP (July 30, 2014) British officials said on Wednesday that driverless cars will be tested on roads in as many as three cities in a trial program set to begin in January. Officials said the tests will last up to three years. (July 30) Video provided by AP
Powered by NewsLook.com
7 Ways to Use Toothpaste: Howdini Hacks

7 Ways to Use Toothpaste: Howdini Hacks

Howdini (July 30, 2014) Fresh breath and clean teeth are great, but have you ever thought, "my toothpaste could be doing more". Well, it can! Lots of things! Howdini has 7 new uses for this household staple. Video provided by Howdini
Powered by NewsLook.com
Amid Drought, UCLA Sees Only Water

Amid Drought, UCLA Sees Only Water

AP (July 30, 2014) A ruptured 93-year-old water main left the UCLA campus awash in 8 million gallons of water in the middle of California's worst drought in decades. (July 30) Video provided by AP
Powered by NewsLook.com
Smartphone Powered Paper Plane Debuts at Airshow

Smartphone Powered Paper Plane Debuts at Airshow

AP (July 30, 2014) Smartphone powered paper airplane that was popular on crowdfunding website KickStarter makes its debut at Wisconsin airshow (July 30) 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:
from the past week

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