Navigation Links
Metal-free catalyst outperforms platinum in fuel cell
Date:6/5/2013

Researchers from South Korea, Case Western Reserve University and University of North Texas have discovered an inexpensive and easily produced catalyst that performs better than platinum in oxygen-reduction reactions.

The finding, detailed in Nature's Scientific Reports online today, is a step toward eliminating what industry regards as the largest obstacle to large-scale commercialization of fuel cell technology.

Fuel cells can be more efficient than internal combustion engines, silent, and at least one type produces zero greenhouse emissions at the tail pipe. Car and bus manufacturers as well as makers of residential and small-business-sized generators have been testing and developing different forms of fuel cells for more than a decade but the high cost and insufficiencies of platinum catalysts have been the Achilles heel.

"We made metal-free catalysts using an affordable and scalable process," said Liming Dai, the Kent Hale Smith Professor of macromolecular science and engineering at Case Western Reserve and one of the report's authors. "The catalysts are more stable than platinum catalysts and tolerate carbon monoxide poisoning and methanol crossover."

And, in their initial tests, a cathode coated with one form of catalystgraphene nanoparticles edged with iodineproved more efficient in the oxygen reduction reaction, generating 33 percent more current than a commercial cathode coated with platinum generated.

The research was led by Jong-Beom Baek, director of the Interdisciplinary School of Green Energy/Low-Dimensional Carbon Materials Center at South Korea's Ulsan National Institute of Science and Technology. Fellow authors include: In-Yup Jeon, Hyun-Jung Choi, Min Choi, Jeong-Min Seo, Sun-Min Jung, Min-Jung Kim and Neojung Park, from Ulsan; Sheng Zhang from Case Western Reserve; and Lipeng Zhang and Zhenhai Xia from North Texas.

Like a battery, a fuel cell converts chemical energy into electrical energy. It works by removing an electron from a fuel, usually hydrogen or methanol mixed with water, at the cell's anode, or positive electrode, creating a current.

Hydrogen ions produced then pass through a membrane to the cathode, or negative electrode. Here, oxygen molecules from the air are split and reduced by the addition of electrons and combined with the hydrogen ions to form water and heatthe only byproducts.

A better, cheaper catalyst than scarce and costly platinum is required if hydrogen fuel cells and direct methanol fuel cells are to become realistic alternatives to fossil fuels, the authors say.

The technology to make alternative catalysts builds on a simple and cheap industrial process several of the researchers developed to make graphene sheets from graphite.

Inside a ball miller, which is a canister filled with steel balls, the researchers broke graphite down into single-layer graphene nanoparticles. While the canister turned, they injected chlorine, bromine or iodine gas to produce different catalysts.

In each case, gas molecules replaced carbon atoms along the zigzag edges of nanoplatelets created by milling. Not only were the edges then favorable to binding with oxygen molecules, but the bond strength between the two oxygen atoms weakened. The weaker the oxygen bonds became, the more efficiently the oxygen was reduced and converted to water at the cathode.

In testing, a cathode coated with iodine-edged nanoplatelets performed best. A cathode coated with bromine-edged nanoparticles generated 7 percent less current than the commercial cathode coated with platinum, the chlorine-edged nanoplatelets 40 percent less.

In a test of durability, electrodes coated with the nanoplatelets maintained 85.6 percent to 87.4 percent of their initial current after 10,000 cycles while the platinum electrodes maintained only 62.5 percent.

Carbon monoxide was added to replicate the poisoning that many scientists blame for the poor performance of platinum at the cathode. The performance of the graphene-based catalysts was unaffected.

When methanol was added to replicate methanol crossover from the anode to cathode in direct methanol fuel cells, the current density of the platinum catalyst dropped sharply. Again, the graphene-based catalysts were unaffected.

"This initial research proves such catalysts work better than platinum," Baek said. "We are working now to optimize the materials."


'/>"/>

Contact: Kevin Mayhood
kevin.mayhood@case.edu
216-368-4442
Case Western Reserve University
Source:Eurekalert

Related biology news :

1. KIT: Processes at the surface of catalysts
2. Low-cost nanosheet catalyst discovered to split hydrogen from water
3. Synthetic molecule first electricity-making catalyst to use iron to split hydrogen gas
4. Painting with catalysts: Nano-engineered materials for detoxifying water by use of sunlight
5. Catalysts that produce green fuel
6. DNA catalysts do the work of protein enzymes
7. Mysterious catalyst explained
8. Insect-eating bat outperforms nectar specialist as pollinator of cactus flowers
9. Platinum is wrong stuff for fuel cells
10. Flower power to purge poison and produce platinum
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:1/11/2017)... , Jan. 11, 2017 Intoxalock, a leading ... the release of its patent-pending calibration device. With this ... perform calibrations, securely upload data logs and process repairs ... customer. "Fighting drunk driving through the application ... public at large, but also for the customer who ...
(Date:1/6/2017)... Jan. 6, 2017  Privately-held CalciMedica, Inc., announced ... healthy volunteers of a novel calcium release-activated calcium ... pancreatitis. Acute pancreatitis, sudden painful ... disorder, but can be very serious.  In severe cases ... where extended hospital stays, time in the ICU ...
(Date:1/6/2017)... 5, 2017  Delta ID Inc., a leader in ... for automotive at CES® 2017. Delta ID has collaborated ... demonstrate the use of iris scanning as a secure, ... driver in a car, and as a way to ... Delta ID and Gentex will demonstrate (booth ...
Breaking Biology News(10 mins):
(Date:1/21/2017)... Interpace Diagnostics Group, Inc. (NASDAQ: IDXG)("Interpace" ... useful molecular diagnostic tests and pathology services, today ... purchase agreement with three  institutional investors to purchase ... in a registered direct offering.  In a concurrent ... to the same investors warrants to purchase 855,000 ...
(Date:1/21/2017)... Jan. 20, 2017 Aratana Therapeutics, Inc. (NASDAQ: ... on the licensing, development and commercialization of innovative biopharmaceutical ... Best Company in North America ... award based on the FDA approval of three ... ENTYCE ® (capromorelin oral solution) and NOCITA ® ...
(Date:1/20/2017)... , ... January 20, 2017 , ... The two newest ... treatment options for patients. Vironika, a spin out from The Wistar Institute, and Sanguis, ... lab space at 3624 Market Street. , Vironika is developing a treatment for ...
(Date:1/20/2017)... , Jan. 20, 2017 Ginkgo ... of Gen9, a pioneer in the synthesis and ... unique expertise in assembling pathway-length synthetic DNA into ... and capacity in the construction of new organism ... industries. "Gen9 was founded to significantly ...
Breaking Biology Technology: