Navigation Links
Metal-free catalyst outperforms platinum in fuel cell

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
Case Western Reserve University

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:
(Date:10/8/2015)... , October 8, 2015 ... or the "Company"), a biometric authentication company focused ... of the Wocket® smart wallet announces that revenues ... were approximately $410,000 compared with $113,00 for the ... the 9 months ended September 30, 2015 were ...
(Date:10/7/2015)... -- NXTD ) ("NXT-ID" or the "Company"), ... commerce market and creator of the Wocket® smart wallet ... term executive at American Express has been appointed to ... ("NXT-ID" or the "Company"), a biometric authentication company focused ... the Wocket® smart wallet announces Mr. Stanley E. ...
(Date:10/6/2015)... Oct. 6, 2015  Maverix Biomics, Inc., a ... to its software portfolio with the debut of ... differential expression in eukaryotes. The software is integrated ... cloud-based genomic analysis solution that leverages proven open-source ... next-generation sequencing efforts. Garry Nolan,s ...
Breaking Biology News(10 mins):
(Date:10/13/2015)... , ... October 13, 2015 , ... ... educational opportunities for school age children in the areas of Science, Technology, Engineering ... sectors of the national economy, and the program aims to increase the number ...
(Date:10/12/2015)... , Oct. 12, 2015 This report ... which include cell type, products, applications, end-user markets and ... REPORT HIGHLIGHTS The global cell expansion market generated ... expected to reach revenues of $9.7 billion in 2015 ... growth rate (CAGR) of 17.8% from 2015 to 2020. ...
(Date:10/12/2015)... , Oct. 12, 2015  Patara Pharma, a ... and inflammatory diseases and conditions, today announced the ... stock financing. Concurrent with the close of its ... a Loan and Security Agreement with Silicon Valley ... $7 million. Patara will use the funds from ...
(Date:10/12/2015)... WA (PRWEB) , ... October 12, 2015 , ... NeuMedics ... the treatment of retinal diseases that can safely and chronically be administered as an ... Health Impact Forum co-hosted by The Cleveland Clinic and taking place October 25th to ...
Breaking Biology Technology: