Researchers develop lower-cost, more efficient nanostructure for fuel cells

Researchers develop lower-cost, more efficient nanostructure for fuel cells
Diagram of a proton exchange membrane fuel cell created using a surface engineering technique called “surface doping.” Credit: Yu Huang Lab/UCLA

A team led by researchers at the UCLA Henry Samueli School of Engineering and Applied Science has developed nanostructures made from a compound of three metals that increases the efficiency and durability of fuel cells while lowering the cost to produce them. Their solution addresses vexing problems that have stalled the adoption of this technology.

Yu Huang, a UCLA associate professor of , was the principal investigator of the research, which was published in the June 12 issue of Science.

Proton exchange membrane fuel cells have shown great promise as a with numerous applications including zero-emission vehicles. The fuel cells work by causing hydrogen fuel and oxygen from the air to react to produce electricity, and the exhaust they create is water—rather than the pollutants and greenhouse gases emitted by traditional car engines.

The chemical processes that take place in fuel cells are catalyzed by metals. One of those processes is an , which has typically used platinum as its catalyst. But the high cost of platinum has been a major factor in hindering wider adoption of fuel cells. Scientists have studied alternative catalysts—including using a platinum–nickel compound—but to date, none has been durable enough to be a viable solution.

To create a that would be more efficient, more durable and less expensive to produce, the researchers used a surface engineering technique called "surface doping," in which they added a third metal called molybdenum to the surface of platinum-nickel . The change made the alloy surface more stable and prevented the loss of nickel and platinum over time.

The study found that nanostructures with the platinum-nickel-molybdenum surface were 81 times more efficient catalysts than catalysts made from a commercial platinum-carbon compound. And the three-metal compound retained about 95 percent of its efficiency over time—significantly better than the efficiency rate of 66 percent or less for platinum-nickel catalysts.

"We showed that the addition of a third transition metal enables improvement in both efficiency and durability to bring down long-term costs," said Huang, who is also a member of the California NanoSystems Institute. "In addition, the doping approach may also apply to a broad range of catalysts and opens up a new route for catalyst engineering for the search of high performance catalysts for environment protection, energy generation and chemical productions."

Explore further

New nanomaterials will boost renewable energy

More information: "High-performance transition metal–doped Pt3Ni octahedra for oxygen reduction reaction." Science 12 June 2015. DOI: 10.1126/science.aaa8765
Journal information: Science

Citation: Researchers develop lower-cost, more efficient nanostructure for fuel cells (2015, June 15) retrieved 18 October 2019 from
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.

Feedback to editors

User comments

Jun 22, 2015
I have not read this paper, but the discovery for a new oxygen reduction reaction catalyst in some research work was based on cyclic voltammetry (CV) and rotating disk electrode RDE using standard three electrode system where the newly discovered catalyst under investigation is stuck on the surface of the working electrode. In CV the catalyst is tested at stagnant condition where diffusion limitation is a problem and without studying the effect of scan rate. In RDE the diffusion limitation problem is solved, however in real Fuel cell the catalyst is sandwiched between the polymer electrolyte and the diffusion medium. In RDE method the rotation rate is increased until the the experimentally measured current becomes independent of the rotation rate. This is the correct current to use in testing the performance of the catalyst not the kinetic current based on Levich type analysis as done by almost all researchers.

Jun 22, 2015
The levich type analysis is based on the following equation:
(kinetic current)-1 + (limiting current)-1 = ( measured current)-1
This equation is derived based on unrealistic assumption such as the ORR is first order with respect of oxygen concentrations. The small region in the polarization curve (less than 0.1 volt) where both diffusion and kinetics are controlling does not resemble the mixed region in a real fuel cell assembly.In RDE setup the measured current in very large potential region almost equal to the limiting and is an indicator of the performance of the catalyst under investigation.So in RDE the Levich equation result in division by zero.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more