- News Home
12 December 2013 1:00 pm ,
Vol. 342 ,
The iconic 125-year-old Lick Observatory on Mount Hamilton near San Jose, California, is facing the threat of closure...
Recent results from the Curiosity Mars rover have helped scientists formulate a plan for the next phase of its mission...
A new, remarkably powerful drug that cripples the hepatitis C virus (HCV) came to market last week, but it sells for $...
In pretoothbrush populations, gumlines would often be marred by a thick, visible crust of calcium phosphate, food...
Evolutionary biologists have long studied how the Mexican tetra, a drab fish that lives in rivers and creeks but has...
Victorian astronomers spent countless hours laboriously charting the positions of stars in the sky. Such sky mapping,...
In an ambitious project to study 1000 years of sickness and health, researchers are excavating the graveyard of the now...
Stefan Behnisch has won awards for designing science labs and other buildings that are smart, sustainable, and...
- 12 December 2013 1:00 pm , Vol. 342 , #6164
- About Us
Turning Gold Into Green
19 October 2005 (All day)
It's a kind of reverse alchemy: Rather than converting lead into gold, chemists have begun investigating how tiny particles of gold can be used to make a myriad of chemical products from plastics to detergent. Now a new study has found a way to fine-tune the approach, potentially making it efficient and safe enough to be attractive to industry.
Oxidation reactions, in which oxygen is added to hydrocarbons, are a crucial way to convert petroleum products into commercial chemicals. Happily, one environmentally friendly source of the oxygen needed for these reactions is freely available in the air as O2. The only trouble is that the oxygen needs a kick-start to begin the reaction, which requires a big energy input. And with all that energy, it's hard to prevent oxygen from forming harmful by-products.
In recent years, scientists have turned to gold as a possible oxidation starter. Though chemically inert in its bulk form, gold is reactive at the nanoscale. However, until recently, scientists haven't been able to make it work without adding hydrogen--and mixing combustible hydrogen and oxygen on a large scale presents a big safety concern.
So how to jump-start the oxygen reaction without hydrogen? Chemist Graham Hutchings of Cardiff University in the U.K. and his team explored this by determining what products form during gold-catalyzed oxidation reactions performed in different solvents. The team found that by choosing solvents carefully, they could tweak the reactions, selectively creating high yields of different products. It was also possible to carefully tune the catalyst and conditions to achieve selective oxidation without any solvent--an important part of "green" chemistry, the researchers report 20 October in Nature.
This paper demonstrates that you don't have to have hydrogen to do these oxidation reactions--and that's a big deal, says chemist Wayne Goodman of Texas A&M University in College Station. The high selectivity of the method's oxidation reactions is "a very exciting result," adds chemical engineer Harold Kung of Northwestern University in Evanston, Illinois. Chemist Masatake Haruta of Tokyo Metropolitan University in Japan agrees, saying that the next step is to better understand how gold particles activate the oxygen. Once the details are better understood, this research will help provide a "roadmap" for pursuing sustainable chemistry, he says.