Washington, Sep 18 (ANI): University of Wisconsin-Madison researchers are working towards developing better catalyst for fuel cells in a bid to make clean cars a reality.
If successful, the researchers could make a car that runs on hydrogen from solar power, and produces water instead of carbon emissions.
Materials science and engineering assistant professor Dane Morgan and Ph.D. student Edward (Ted) Holby have developed a computational model that could optimise an important component of fuel cells, making it possible for the technology to have a more widespread use.
The researchers investigated how particle size is related to the overall stability of a material, and showed with their model that increasing the particle size of a fuel cell catalyst decreases degradation and therefore increases the useful lifetime of a fuel cell.
Fuel cells are electrochemical devices that facilitate a reaction between hydrogen and oxygen, producing electrical power and forming water.
In the type of fuel cells Morgan is researching, called proton exchange membrane fuel cells (PEMFCs), hydrogen is split into a proton and electron at one side of the fuel cell (the anode).
The proton moves through the device while the electron is forced to travel in an external circuit, where it can perform useful work, while at the other side of the fuel cell (the cathode), the protons, electrons and oxygen combine to form water, which is the only waste product.
One of the many hurdles to producing efficient fuel cells for widespread use is the catalyst added to aid the reaction between protons, electrons and oxygen at the cathode.
Current fuel cells use platinum and platinum alloys as a catalyst. While platinum can withstand the corrosive fuel cell environment, it is expensive and not very abundant.
Thus, to maximize platinum use, researchers use catalysts made with platinum particles as small as two nanometers, which are approximately 10 atoms across.
These tiny structures have a large surface area on which the fuel cell reaction occurs.
However, platinum catalysts this small degrade very quickly, which means that the fuel cell doesn’t last long.
The researchers have found a possible solution to the rapid degradation problem-when it comes to catalyst particle size, sometimes smaller isn’t better.
In their modelling work, they showed that if the particle size of a platinum catalyst is increased to four or five nanometers, which is approximately 20 atoms across, the level of degradation significantly decreases.
This means the catalyst and the fuel cell as a whole can continue to function for much longer than if the particle size was only two or three nanometers.
“Fuel cells are just one of many energy technologies – solar, battery, etc. – with enormous potential to reduce our dependence on oil and our carbon emissions. Computer simulation offers a powerful tool to understand and develop new materials at the heart of these energy technologies,” said Morgan. (ANI)
Medical researchers face conflicts of interest
By Julie Steenhuysen
CHICAGO (Reuters) – Dr. Bruce Psaty of University of Washington in Seattle knows how easy it can be to fall under the spell of a friendly relationship with drug companies.
As an assistant professor, he published an article on using beta-blockers to treat high blood pressure that caught the attention of the pharmaceutical industry.
“My family and I were invited to a first-class resort, where I presented the results at a sponsored conference,” Psaty wrote in a commentary this week in the Journal of the American Medical Association.
He agreed to help develop a set of slides on beta-blockers and soon found himself suggesting that the drug company’s studies be featured, in part because he felt “a kind of social duty to reciprocate both the kindness and the investment made by the sponsor in the slide set.”
Psaty said his own story illustrates the subtleties of conflicts of interest. He is dissatisfied with the current debate among doctors, spurred by reports last year by Iowa Republican Senator Charles Grassley that a prominent Harvard psychiatrist failed to fully disclose hefty payments from drug companies.
“The debate has not been terribly fruitful,” Psaty said in a telephone interview. He said conflicts are sometimes hard to recognize, pointing to the work of Dan Ariely, a behavioral economist at Duke University in North Carolina.
Ariely’s research suggests that most people are comfortable with just a little bit of cheating, without considering themselves dishonest. He says subtle conflicts of interest often color decision making, yet most people — especially doctors — think they are immune.
HUMAN INSTINCT
“It’s human instinct,” Ariely said in a telephone interview. “If someone does something nice — gives you $5 million in a research grant — don’t you want to do something nice back to them?”
Ariely said return favors could come in the form of excluding a sicker patient from a clinical trial, which might affect the study results. “Not on purpose, but I’m trying to help my friends, just a little bit.”
Several states including Massachusetts, Minnesota and Vermont are tightening restrictions on gifts to doctors in the hopes of preventing such conflicts.
And a bill introduced by Senators Grassley and Wisconsin Democrat Herb Kohl would compel doctors to disclose their financial ties with drug companies or face stiff fines.
Psaty said such laws may curb some financial conflicts, but a bigger challenge will be addressing the influence drugmakers have over company-funded research supporting the safety and effectiveness of the drugs they make.
Psaty said he accepts no funding from drug companies for his research, but short of having all clinical trials funded with public money, he suggests doctors look for red flags in studies that might indicate bias.
“Was the question a good question? Did they set the study up right? Did they use the weakest possible comparator to make a drug look good in a trial?” he said.
And when a medical journal editorial disagrees with the primary interpretation of the author, “that is a potential marker of a study where there may been some bias from conflict of interest,” he said.
(Editing by Maggie Fox and Sandra Maler)