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:8/5/2020)... ... ... Regenative Labs has received approval from the Centers for Medicare & Medicaid Services ... jelly allografts to be assigned a Q code and be approved for application directly ... allograft product to be recognized as a 361 HCT/P by CMS regulated under 21CFR ...
(Date:7/31/2020)... ... July 30, 2020 , ... Justin Zamirowski to lead ... near term focus on Type 2 diabetes and associated comorbidities. , Justin brings ... areas and classes. As Chief Commercial Officer, Justin will lead Better Therapeutics’ ...
(Date:7/18/2020)... ... ... Commercial launch readiness is a critical stage in a product life cycle. ... the global economic downturn will only increase price pressures overall for the industry. The ... value from every product launch is critical. However, history shows that only a third ...
Breaking Biology News(10 mins):
(Date:7/18/2020)... ... ... After research model surgery and catheter implantation, the long journey of catheter ... of a successful study, while protecting and accessing the catheter or device post-surgery is ... from Envigo in a live webinar on Wednesday, August 5, ...
(Date:7/18/2020)... ... July 16, 2020 , ... Medial ... early detection and prevention of high-burden diseases, and Centric Consulting, a business and ... organizations to utilize existing data in order to identify and prioritize patients for ...
(Date:7/10/2020)... ... July 08, 2020 , ... Bode ... significant expansion of laboratory operations through its COVID-19 testing service, Bode-CARES . ... , Bode-CARES provides a turnkey solution that includes a comprehensive ...
(Date:7/10/2020)... ... July 09, 2020 , ... ... is commonly used to suppress pigment formation in zebrafish embryos, maintaining optical transparency ... led by Dr MA has been using the zebrafish model to investigate the ...
Breaking Biology Technology: