Even small devices need power, and much of that juice comes from fuel cells. As these devices become even smaller, the rush is on to find more efficient ways to power them.
In the last several years, scientists have discovered that palladium, a metal, is a strong candidate for providing that initial boost that helps fuel cells go. Palladium is far cheaper than another popular fuel cell catalyst, platinum, and it’s more abundant.
But researchers have wrestled with creating palladium nanoparticles with enough active surface area to make catalysis efficient in fuel cells while preventing particles from clumping together during the chemical processes that convert a fuel source to electricity. Two Brown University chemists have found a way to overcome those challenges.
The scientists report in the online edition of the Journal of the American Chemical Society that they have produced palladium nanoparticles with about 40 percent greater surface area than commercially available palladium particles. The Brown catalysts also remain intact four times longer than what’s currently available.
“This approach is very novel. It works,” said Vismadeb Mazumder, a graduate student who joined chemistry professor Shouheng Sun on the paper. “It’s two times as active, meaning you need half the energy to catalyze. And it’s four times as stable.”
Mazumder and Sun created palladium nanoparticles 4.5 nanometers in size. They attached the nanoparticles to a carbon platform at the anode end of a direct formic acid fuel cell. The researchers then did something new: They used weak binding amino ligands to keep the palladium nanoparticles separate and at the same size as they’re attached to the carbon platform. By keeping the particles separate and uniform in size, they increased the available surface area on the platform and raised the efficiency of the fuel cell reaction.
“It just works better,” Sun said.
What’s also special about the ligands is that they can be “washed” from the carbon platform without jeopardizing the integrity of the separated palladium nanoparticles. This is an important step, Mazumder emphasized, because previous attempts to remove binding ingredients have caused the particles to lose their rigid sizes and clump together, which gums up the reaction.
The Brown team said in experiments lasting 12 hours, their catalysts lost 16 percent of its surface area, compared to a 64-percent loss in surface area in commercial catalysts.
“We managed to ebb the decay of our catalyst by our approach,” said Mazumder, who is in his second year in Sun’s lab. “We made high-quality palladium nanoparticles, put them efficiently on a support, then removed them from the stabilizers efficiently without distorting catalyst quality.”
The Brown scientists now are looking at various palladium-based catalysts with enhanced activity and stability for future fuel cell applications.
“We want to make it cheaper with analogous activity,” Mazumder said.
The research was funded by the Division of Materials Research of the National Science Foundation and a Brown seed fund.
Richard Lewis | EurekAlert!
Cancer diagnosis: no more needles?
25.05.2018 | Christian-Albrechts-Universität zu Kiel
Less is more? Gene switch for healthy aging found
25.05.2018 | Leibniz-Institut für Alternsforschung - Fritz-Lipmann-Institut e.V. (FLI)
The more electronics steer, accelerate and brake cars, the more important it is to protect them against cyber-attacks. That is why 15 partners from industry and academia will work together over the next three years on new approaches to IT security in self-driving cars. The joint project goes by the name Security For Connected, Autonomous Cars (SecForCARs) and has funding of €7.2 million from the German Federal Ministry of Education and Research. Infineon is leading the project.
Vehicles already offer diverse communication interfaces and more and more automated functions, such as distance and lane-keeping assist systems. At the same...
A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.
The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...
At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.
At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...
There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?
At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
25.05.2018 | Event News
02.05.2018 | Event News
13.04.2018 | Event News
25.05.2018 | Event News
25.05.2018 | Machine Engineering
25.05.2018 | Life Sciences