For vehicles and heavy-duty automobiles that should journey lengthy distances with out frequent, time-consuming charging stops, batteries usually fall quick. Hydrogen gasoline cells — which will be refueled as rapidly as conventional gasoline — provide a cleaner, extra environment friendly different.
Now, researchers at UCLA have made a breakthrough that would dramatically lengthen the lifespan of those gasoline cells, making them a extra viable clear power supply that may assist deliver sustainable, long-haul trucking nearer to actuality.
Led by Yu Huang, a professor of supplies science and engineering on the UCLA Samueli Faculty of Engineering, the analysis group has developed a brand new catalyst design able to pushing the projected gasoline cell catalyst lifespans to 200,000 hours, which is almost seven instances the U.S. Division of Power’s goal for 2050. Printed in Nature Nanotechnology, the analysis marks a big step towards the widespread adoption of gasoline cell know-how in heavy-duty automobiles, reminiscent of long-haul tractor trailers.
Though medium- and heavy-duty vehicles make up solely about 5% of automobiles on the street, they’re liable for almost 1 / 4 of greenhouse gasoline car emissions, in keeping with federal estimates. This makes heavy-duty purposes a super entry level for polymer electrolyte membrane gasoline cell know-how.
As a result of gasoline cells are considerably lighter than batteries, they require much less power to maneuver the automobiles. With a projected energy output of 1.08 watts per sq. centimeter, gasoline cells that includes the brand new catalyst can ship the identical efficiency as typical batteries that weigh as much as eight instances extra. This distinction is particularly related for heavy-duty automobiles, which not solely carry substantial cargo but in addition are usually a lot heavier than normal automobiles. As well as, constructing a nationwide hydrogen-refueling infrastructure would probably require much less funding than establishing an electrical vehicle-charging community throughout the nation.
Gas cells work by changing the chemical power saved in hydrogen into electrical energy, emitting solely water vapor as a byproduct. This has made them a promising answer for cleaner transportation. Nevertheless, the gradual chemical response for the power conversion has been a problem, requiring a catalyst to realize sensible speeds.
Whereas platinum-alloy catalysts have traditionally delivered superior chemical response, the alloying parts leach out over time, diminishing catalytic efficiency. The degradation is additional accelerated by the demanding voltage cycles required to energy heavy-duty automobiles.
To handle this problem, the UCLA group has engineered a sturdy catalyst structure with a novel design that shields platinum from the degradation sometimes noticed in alloy techniques.
The researchers started by embedding ultrafine platinum nanoparticles inside protecting graphene pockets. Composed of a single layer of carbon atoms organized in a two-dimensional honeycomb lattice, graphene is the thinnest recognized materials. Regardless of its atomic thinness, it’s extremely sturdy, light-weight and extremely conductive. These graphene-encased nanoparticles have been then nested contained in the porous construction of Ketjenblack, a powdery carbon materials. This “particles-within-particles” design supplies long-term stability whereas preserving the excessive catalytic exercise important for environment friendly gasoline cell efficiency.
“Heavy-duty gasoline cell techniques should face up to harsh working circumstances over lengthy durations, making sturdiness a key problem,” mentioned Huang, who holds the Traugott and Dorothea Frederking Endowed Chair at UCLA Samueli. “Our pure platinum catalyst, enhanced with a graphene-based safety technique, overcomes the shortcomings of typical platinum alloys by stopping the leaching of alloying parts. This innovation ensures that the catalyst stays energetic and strong, even underneath the demanding circumstances typical of long-haul purposes.”
The brand new catalyst exhibited an influence lack of lower than 1.1% after an accelerated stress take a look at involving 90,000 square-wave voltage cycles designed to simulate years of real-world driving, the place even a ten% loss is usually thought-about glorious. These superior outcomes challenge gasoline cell lifetimes exceeding 200,000 hours, far surpassing the DOE’s goal of 30,000 hours for heavy-duty proton alternate membrane gasoline cell techniques.
By efficiently addressing the twin challenges of catalytic exercise and sturdiness, UCLA researchers’ revolutionary catalyst design holds nice promise for the adoption of hydrogen-powered heavy-duty automobiles — an important step towards lowering emissions and enhancing gasoline effectivity in a sector that accounts for a considerable share of transportation power use.
The group’s findings constructed on its earlier success in creating a gasoline cell catalyst for light-duty automobiles that demonstrated a lifespan of 15,000 hours — almost doubling the DOE’s goal of 8,000 hours.
The brand new research’s lead authors are UCLA Ph.D. graduates Zeyan Liu and Bosi Peng, each suggested by Huang, whose analysis group makes a speciality of creating nanoscale constructing blocks for advanced supplies, reminiscent of gasoline cell catalysts. Xiaofeng Duan, a professor of chemistry and biochemistry at UCLA, and Xiaoqing Pan, a professor of supplies science and engineering at UC Irvine, are additionally authors on the paper. Huang and Duan are each members of the California NanoSystems Institute at UCLA.
Different authors on the paper are Yu-Han “Joseph” Tsai and Ao Zhang from UCLA, in addition to Mingjie Xu, Wenjie Zang, XingXu Yan and Li Xing from UC Irvine.
UCLA’s Expertise Growth Group has filed a patent on the know-how.