Archive
2015
January
February
March
April
May
June
July
August
October
2014
January
February
March
April
May
June
July
August
September
October
November
December
2013
September
October
November
December
Feb. 14, 2014

Picture of the Week: Nanoparticle Heart

by Jessica McDonald

Click to enlarge images
It’s easy for ethanol to combust in an engine at high temperatures, but fuel cells operate at room temperature. That’s where nanoparticles like this heart-shaped one, which is an alloy of three metals—platinum, iridium, and tin—come in. Grouped together, they act as a catalyst in fuel cells, driving the production of energy from ethanol without the need for extra heat.
 
“This is a very special type of catalyst, which we use to oxidize ethanol into water and carbon dioxide,” says Xiaowei Teng, an assistant professor of chemical engineering at the University of New Hampshire, who spearheads work on the material. The process releases electrons that can be used to power cars, cell phones, and other devices that require electricity.
 
In the image above, which has been artificially colored red, each dot is an atom of one of the three elements. Dong Su, a scientist at Brookhaven National Laboratory on Long Island, used electron microscopy to reveal the nanoparticle’s structure. The unusual heart shape wasn’t intentional, Teng says, but “it might expose more active sites for catalytic reactions.”
 
Platinum has long been used as a catalyst for many chemical reactions, but because it’s very expensive, reducing the amount used in fuel cells is an active area of research. Teng says that combining other metals with platinum reduces the amount of the pricey material needed and improves how well the fuel cell works. Tin, for example, can make the reaction go 10-30 times faster. Iridium, meanwhile, can help convert the ethanol completely into carbon dioxide instead of acetic acid, which is less efficient at producing energy.
 
Teng sees ethanol fuel cells as more practical than the traditional idea of using hydrogen for energy. For one, hydrogen is extremely flammable, and transportation of the gas is dangerous. “To a certain degree, it's a moving bomb,” says Teng. By comparison, ethanol is relatively benign—Teng’s group oxidizes solutions that are in the range of 5-40 percent ethanol, which is essentially like working with beer or whiskey. Plus, gas stations mix ethanol—a biofuel made from corn and other plant materials—in their pumps, so the infrastructure is already there.
 
Work on the fuel cell is still in the early stages. The efficiency is low—Teng's team is able to convert 10-15 percent of ethanol into carbon dioxide at most, and the rest ends up as acetic acid. But by continuing to tweak the alloy, and by learning more about how its structure affects its function, he hopes to maximize the amount of energy he can get out of the 2-3 nanometer-sized particles. Regardless, he’s putting his heart into it. 

 

About Jessica McDonald

Jessica McDonald is a health reporter for WHYY, Philadelphia's public radio station. She is also a former SciFri intern.

The views expressed are those of the author and are not necessarily those of Science Friday.
EVAL ERROR: Entity: line 1: parser error : Space required after the Public Identifier

                                                 ^
Entity: line 1: parser error : SystemLiteral " or ' expected

                                                 ^
Entity: line 1: parser error : SYSTEM or PUBLIC, the URI is missing

                                                 ^

Code:
line 1: package tmpevalpackage;
line 2: sub doEval { 
line 3: 	my($parent);
line 4: 	
line 5: 	if($LayoutManager::url_resolved_values{'SEGMENT.nickname'}) {
line 6: 		$parent = $LayoutManager::url_resolved_values{'SEGMENT.nickname'};
line 7: 	}
line 8: 	elsif($LayoutManager::url_resolved_values{'VIDEO.nickname'}) {
line 9: 		$parent = $LayoutManager::url_resolved_values{'VIDEO.nickname'};
line 10: 	}
line 11: 	elsif($LayoutManager::url_resolved_values{'DOCUMENT.nickname'}) {
line 12: 		$parent = $LayoutManager::url_resolved_values{'DOCUMENT.nickname'}
line 13: 	}
line 14: 	
line 15: 	if($parent) {
line 16: 		my(@books) = &Database::SelectClause('BOOK',"parent = $parent");
line 17: 		if(!@books) {
line 18: 			$parent = '';
line 19: 		}
line 20: 	}
line 21: 	
line 22: 	if(!$parent) {
line 23: 		my(@sel) = &Database::SelectClause('GLOBAL','record all ""');
line 24: 		if(@sel) {
line 25: 			$parent = 'GLOBAL.' . $sel[0];
line 26: 		}
line 27: 			$main::ENV{'reading_header'} = "FEATURED READING";
line 28: 	}
line 29: 	
line 30: 	 = '';
line 31: 	
line 32: 	if($parent) {
line 33: 		my(@books) = &Database::SelectClause('BOOK',"parent = $parent");
line 34: 		0 = 0;
line 35: 		my $dots;
line 36: 		foreach(@books) {
line 37: 			my(%data);
line 38: 			&Database::GetRow($_,'BOOK',\%data);
line 39: 			my($status,$title,$author,$url,$image,$width,$height) = &SciFri::Schema::getAmazonItem($data{'isbn'});
line 40: 			if($data{'title'}) {
line 41: 				$title = $data{'title'};
line 42: 			}
line 43: 			if($data{'author'}) {
line 44: 				$author = $data{'author'};
line 45: 			}
line 46: 			if($status eq 'ok') {
line 47: 				 .= "<div class=\"box-2x1-item box-slide\" data-href=\"$url\">";
line 48: 				 .= "	<div class=\"box-2x1-item-photo\">";
line 49: 				 .= "		<div class=\"image-wrapper\" data-jsclass=\"imageWrapper\" data-align=\"right\">";
line 50: 				 .= "			<img src=\"$image\" data-width=\"$width\" data-height=\"$height\">";
line 51: 				 .= "		</div>";
line 52: 				 .= "	</div>";
line 53: 				 .= "	<h4>$title</h4>";
line 54: 				if($author) {
line 55: 					 .= "	<p>by $author</p>";
line 56: 				}
line 57: 				 .= "	<div class=\"box-2x1-more-button\"><a href=\"$url\"><img src=\"/images/v1/icon_text_more_white.png\" width=47 height=15 border=0></a></div>";
line 58: 				 .= "</div>";
line 59: 				++0;
line 60: 			}
line 61: 		}
line 62: 	}
line 63: 	if($parent eq "GLOBAL.1") { $main::ENV{'reading_header'} = "FEATURED READING"; }
line 64: 	else { $main::ENV{'reading_header'} = "RELATED READING"; }
line 65:  };
line 66: &doEval();
line 67: 1;

Science Friday® is produced by the Science Friday Initiative, a 501(c)(3) nonprofit organization.

Science Friday® and SciFri® are registered service marks of Science Friday, Inc. Site design by Pentagram; engineering by Mediapolis.

 

topics