Unabogie
4th June 2007, 08:25 PM
http://www.azonano.com/news.asp?newsID=1326
The new technique combines two previously known methods for producing hydrogen. The previous methods have limitations making them impractical when used alone, but those drawbacks are overcome when the methods are combined, Varma said.
One of the methods was invented by Herbert C. Brown, a chemist and Nobel laureate from Purdue who discovered a compound called sodium borohydride during World War II. The compound contains sodium, boron and hydrogen. He later developed a technique for producing hydrogen by combining sodium borohydride with water and a catalyst. The method, however, has a major drawback because it requires expensive catalysts such as ruthenium.
The other method involves a chemical reaction in which tiny particles of aluminum are combined with water in such a way that the aluminum ignites, releasing hydrogen during the combustion process. This method does not require an expensive catalyst, but it yields insufficient quantities of hydrogen to be practical for fuel cell applications.
"Our solution is to combine both methods by using what we call a triple borohydride-metal-water mixture, which does not require a catalyst and has a high enough hydrogen yield to make the method promising for fuel cell applications," Varma said. "So far we have shown in experiments that we can convert 6.7 percent of the mixture to hydrogen, which means that for every 100 grams of mixture we can produce nearly 7 grams of hydrogen, and that yield is already better than alternative methods on the market."
Anyone know more about this?
The new technique combines two previously known methods for producing hydrogen. The previous methods have limitations making them impractical when used alone, but those drawbacks are overcome when the methods are combined, Varma said.
One of the methods was invented by Herbert C. Brown, a chemist and Nobel laureate from Purdue who discovered a compound called sodium borohydride during World War II. The compound contains sodium, boron and hydrogen. He later developed a technique for producing hydrogen by combining sodium borohydride with water and a catalyst. The method, however, has a major drawback because it requires expensive catalysts such as ruthenium.
The other method involves a chemical reaction in which tiny particles of aluminum are combined with water in such a way that the aluminum ignites, releasing hydrogen during the combustion process. This method does not require an expensive catalyst, but it yields insufficient quantities of hydrogen to be practical for fuel cell applications.
"Our solution is to combine both methods by using what we call a triple borohydride-metal-water mixture, which does not require a catalyst and has a high enough hydrogen yield to make the method promising for fuel cell applications," Varma said. "So far we have shown in experiments that we can convert 6.7 percent of the mixture to hydrogen, which means that for every 100 grams of mixture we can produce nearly 7 grams of hydrogen, and that yield is already better than alternative methods on the market."
Anyone know more about this?