The material, from a family of minerals called oxides, could replace platinum, a rare and expensive metal that is currently used in diesel engines to try to control the amount of pollution released into the air.
In a study published in the August 17 issue of Science, researchers found that when a manmade version of the oxide mullite replaces platinum, pollution is up to 45 percent lower than with platinum catalysts.
“Many pollution control and renewable-energy applications require precious metals that are limited – there isn’t enough platinum to supply the millions and millions of automobiles driven in the world,” said Dr. Kyeongjae “K.J.” Cho, professor of materials science and engineering and physics at UT Dallas and a senior author of study. “Mullite is not only easier to produce than platinum, but also better at reducing pollution in diesel engines.”
For the environmentally conscious, the higher fuel efficiency of diesel engines makes an attractive alternative to engines that run on gasoline. On the flip side, compared with gasoline engines, diesel vehicles produce more nitric oxide (NO) and nitrogen dioxide (NO2), which are known as NOx pollutants.
In June, the World Health Organization upgraded the classification of diesel engine exhaust as carcinogenic in humans, putting it in the same category as cigarette smoke and asbestos. Countries throughout the world have drafted guidelines to reduce diesel air pollution in the next decade.
Platinum, because of its expense to mine and limited supply, is considered a precious metal. Estimates suggest that for 10 tons of platinum ore mined, only about one ounce of usable platinum is produced.
In 2003, Cho became a co-founder and lead scientist at Nanostellar, a company created to find catalysts through a material design that would replace platinum in reducing diesel exhaust (Carbon monoxide, or CO, and NOx pollutants). His company has designed and commercialized a platinum-gold alloy catalyst that is a viable alternative to platinum alone, but until this experiment with mullite, had not found a catalyst made of materials that are less expensive to produce.
Cho, also a visiting professor at Seoul National University in South Korea, and his team suspected that the oxygen-based composition of mullite, originally found off the Isle of Mull in Scotland, might prove to be a suitable alternative. His team synthesized mullite and used advanced computer modeling techniques to analyze how different forms of the mineral interacted with oxygen and NOx. After computer modeling confirmed the efficiency of mullite to consume NOx, researchers used the oxide catalyst to replace platinum in diesel engine experiments.
“Our goal to move completely away from precious metals and replace them with oxides that can be seen commonly in the environment has been achieved,” Dr. Cho said. “We’ve found new possibilities to create renewable, clean energy technology by designing new functional materials without being limited by the supply of precious metals.”
The mullite alternative is being commercialized under the trademark name Noxicat. Dr. Cho and his team will also explore other applications for mullite, such as fuel cells.
Dr. Weichao Wang, who earned his PhD in materials science and engineering in 2011 under Dr. Cho’s supervision in Erik Jonsson School of Engineering and Computer Science at UT Dallas, was lead author of this study. Researchers from the University of Kentucky and Huazhong University of Science and Technology in China were also involved in this work.
The study was supported by the Texas Advanced Computing Center, Nanostellar and the National Research Foundation of Korea.
LaKisha Ladson | Newswise Science News
Glass's off-kilter harmonies
18.01.2017 | University of Texas at Austin, Texas Advanced Computing Center
Explaining how 2-D materials break at the atomic level
18.01.2017 | Institute for Basic Science
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
19.01.2017 | Earth Sciences
19.01.2017 | Life Sciences
19.01.2017 | Physics and Astronomy