Featured Research

from universities, journals, and other organizations

A First: Hydrogen Atoms Manipulated Below The Surface Of A Palladium Crystal

Date:
December 18, 2005
Source:
Penn State / Eberly College Of Science
Summary:
For the first time, scientists have manipulated hydrogen atoms into stable sites beneath the surface of a palladium crystal, creating a structure predicted to be important in metal catalysts, in hydrogen storage, and in fuel cells. Observations of the effects of the resulting subsurface hydrides--hydrogen atoms with a partial negative charge--confirmed the existence of the stable sites, which had been predicted but previously had neither been deliberately assembled nor directly observed.

The writing is less than half an Angstrom (0.00005 microns) "tall" off the surface. The characters are less than 500 Angstrom (0.05 microns) high. They were created when Weiss and his team moved hydrogen atoms underneath a palladium surface using a custom-built, ultrastable, low-temperature, scanning tunneling microscope.
Credit: Image courtesy of Penn State / Eberly College Of Science

For the first time, scientists have manipulated hydrogen atoms into stable sites beneath the surface of a palladium crystal, creating a structure predicted to be important in metal catalysts, in hydrogen storage, and in fuel cells. The research will be published in the 13 December 2005 issue of the journal Proceedings of the National Academy of Science.

Observations of the effects of the resulting subsurface hydrides--hydrogen atoms with a partial negative charge--confirmed the existence of the stable sites, which had been predicted but previously had neither been deliberately assembled nor directly observed. The research was led by Paul S. Weiss, Distinguished Professor of Chemistry and Physics at Penn State.

After moving absorbed hydrogen atoms to just below the crystal surface, the researchers were able to observe how the presence of the hydride in specific sites within a metal crystal affects the chemical, physical, and electronic properties of the metal. Understanding these effects could advance efforts to improve chemical reactions involving metal catalysts. In addition, the subsurface hydride may provide a model material for application in hydrogen storage and fuel cells. The ability to prepare the subsurface hydride provides an important research tool for these applications.

Weiss points out that hydrogen atoms just below the surface of the metal have been thought to be important in a number of chemical reactions. "Indirect experimental data have shown that chemically reactive hydrogen atoms were located at such sites, but there was no way to test them," says Weiss. "This material will allow us to test the predictions and to apply data from direct observation."

The researchers carried out the experiments in a low-temperature scanning tunneling microscope (STM) under ultrahigh vacuum by exposing the crystal to a hydrogen atmosphere. They removed excess hydrogen from the surface by cycles of exposure to heat and oxygen. After the surface had been cleaned, the researchers were able to use electrons from the STM tip to move hydrogen atoms that had been absorbed into the bulk metal up into the stable subsurface sites. As the hydride formed underneath the surface of the material, Weiss and his team observed that the surface of the crystal distorted, the positive charge of palladium atoms above them increased, and interactions occurred with hydrogen atoms on the surface of the palladium crystal. "One of the most interesting aspects of the research was the ability to move atoms beneath the surface," Weiss says. "The observation of the effects of the populated sites, such as surface distortion, confirmed the existence of the stable sites and the theoretical predictions of the physical and electrical properties of the hydrides."

Years ago, Weiss was the first on an IBM team to manipulate xenon atoms on a metal surface. His coworkers later moved atoms to spell out their corporate logo. By extending the ability to manipulate atoms beyond the surface of a material, this research is expected to advance the understanding and control of important chemical reactions in a variety of commercial applications. In addition, this ability has potential as a model system of a technologically important material.

In addition to Weiss, other members of the research team include E. Charles H. Sykes, a former postdoctoral fellow in the Weiss lab who is now an assistant professor of chemistry at Tufts University; Luis C. Fernandez-Torres, a former postdoctoral fellow in the Weiss lab who is now an assistant professor of chemistry at the University of Puerto Rico at Cayey; Sanjini U. Hanayakkara, a Penn State graduate student; Brent A. Mantooth, a former graduate student in the Weiss lab who is now a scientist at SAIC Research and Development Center; and Ryan M. Nevin, a former REU undergraduate in the Weiss lab who is now a graduate student at the University of Wisconsin.

This research was funded by the Air Force Office of Scientific Research, with additional support from the Army Research Office, the National Science Foundation, and the Office of Naval Research.


Story Source:

The above story is based on materials provided by Penn State / Eberly College Of Science. Note: Materials may be edited for content and length.


Cite This Page:

Penn State / Eberly College Of Science. "A First: Hydrogen Atoms Manipulated Below The Surface Of A Palladium Crystal." ScienceDaily. ScienceDaily, 18 December 2005. <www.sciencedaily.com/releases/2005/12/051217010703.htm>.
Penn State / Eberly College Of Science. (2005, December 18). A First: Hydrogen Atoms Manipulated Below The Surface Of A Palladium Crystal. ScienceDaily. Retrieved September 2, 2014 from www.sciencedaily.com/releases/2005/12/051217010703.htm
Penn State / Eberly College Of Science. "A First: Hydrogen Atoms Manipulated Below The Surface Of A Palladium Crystal." ScienceDaily. www.sciencedaily.com/releases/2005/12/051217010703.htm (accessed September 2, 2014).

Share This




More Matter & Energy News

Tuesday, September 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Halliburton Reaches $1B Gulf Spill Settlement

Halliburton Reaches $1B Gulf Spill Settlement

AP (Sep. 2, 2014) Halliburton's agreement to pay more than $1 billion to settle numerous claims involving the 2010 BP oil spill could be a way to diminish years of costly litigation. A federal judge still has to approve the settlement. (Sept. 2) Video provided by AP
Powered by NewsLook.com
Google Teases India Event, Possible Android One Reveal

Google Teases India Event, Possible Android One Reveal

Newsy (Sep. 1, 2014) Google has announced a Sept. 15 event in India during which they're expected to reveal their Android One phones. Video provided by Newsy
Powered by NewsLook.com
Australian Airlines Relax Phone Ban Too

Australian Airlines Relax Phone Ban Too

Reuters - Business Video Online (Aug. 26, 2014) Qantas and Virgin say passengers can use their smartphones and tablets throughout flights after a regulator relaxed a ban on electronic devices during take-off and landing. As Hayley Platt reports the move comes as the two domestic rivals are expected to post annual net losses later this week. Video provided by Reuters
Powered by NewsLook.com
Hurricane Marie Brings Big Waves to California Coast

Hurricane Marie Brings Big Waves to California Coast

Reuters - US Online Video (Aug. 26, 2014) Huge waves generated by Hurricane Marie hit the Southern California coast. Rough Cut (no reporter narration). Video provided by Reuters
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