Softer nanomaterials can make fuel cell cars cheaper



[ad_1]

A platinum-type metal of only five atomic layers of thickness is "entirely appropriate" to optimize the performance of a fuel cell electrode. Credit: image of Johns Hopkins University / Lei Wang

According to a new study by Johns Hopkins, a new method of increasing the reactivity of ultra-thin nanowires, of a thickness of only a few atoms, will one day make fuel cells hydrogen cars less expensive.

A report of the conclusions, which will be published on 22 February in Science, the offers promise faster and cheaper production of electrical energy using fuel cells, but also bulk chemicals and materials such as hydrogen.

"Each material undergoes surface stresses due to the breakage of the crystalline symmetry of the material at the atomic level.We have discovered a way to make these crystals ultra-thin, thus reducing the distance between atoms and increasing the reactivity of the material", explains Chao Wang, assistant professor of chemical and biomolecular engineering at Johns Hopkins University and one of the authors of the study.

The stress is, in short, the deformation of any material. For example, when a piece of paper is folded, it is effectively disturbed at the smallest atomic level; the intricate lattices that hold the paper together are forever changed.

In this study, Wang and his colleagues manipulated the effect of stress, or distance between atoms, causing a radical change in the material. By making these networks incredibly thin, about a million times thinner than a strand of human hair, the material becomes much easier to handle, just as a paper is easier to fold than a thicker stack of paper.




Animated illustration of how intrinsic surface stress promotes the responsiveness of the electrocatalyst. Credit: Zhenhua Zeng and Jeffrey Greeley

"We're basically using the force to adjust the properties of the thin plates that make up the electrocatalysts, which are part of the fuel cell electrodes," says Jeffrey Greeley, professor of chemical engineering at Purdue, as well as another of the corresponding authors of the document. "The ultimate goal is to test this method on a variety of metals."

"By adjusting the fineness of the materials, we have been able to create more stresses, which changes the properties of the material, including how the molecules are held together, which means you have more freedom to accelerate the desired reaction on the material. surface of the material, "Wang explains.

The increased activity of catalysts used in fuel cell cars is an example of the usefulness of optimization reactions in the application. While fuel cells represent a promising technology for zero-emission EVs, the challenge lies in the expense associated with precious metal catalysts such as platinum and palladium, which limits its viability to the vast majority of consumers . A more active catalyst for fuel cells can reduce costs and pave the way for widespread adoption of green and renewable energies.

Softer nanomaterials can make fuel cell cars cheaper

Chao Wang, assistant professor of chemical and biomolecular engineering at Johns Hopkins, in his lab with Lei Wang, another author of the related research article. Credit: Will Kirk / Johns Hopkins University

Wang and his colleagues believe that their new method can increase catalyst activity by 10 to 20 times, using 90% fewer precious metals than is currently required to power a fuel cell.

"We hope that our results will one day contribute to the production of cheaper and more efficient fuel cells to make green cars more accessible to everyone," Wang said.


Explore further:
A gilding technique inspired by the ancient Egyptians could produce better fuel cells for the electric cars of tomorrow

More information:
L. Wang et al., "Tunable Intrinsic Deformation in Two-Dimensional Transition Metal Electrocatalysts" Science (2019). science.sciencemag.org/cgi/doi… 1126 / science.aat8051

Journal reference:
Science

Provided by:
Johns Hopkins University

[ad_2]

Source link