Nav: Home

Ammonia synthesis made easy with 2D catalyst

November 25, 2019

HOUSTON - (Nov. 25, 2019) - Rice University researchers have developed an inorganic method to synthesize ammonia that is both environmentally friendly and can produce the valuable chemical on demand under ambient conditions.

The Brown School of Engineering lab of materials scientist Jun Lou manipulated a two-dimensional crystal it understands well -- molybdenum disulfide -- and turned it into a catalyst by removing atoms of sulfur from the latticelike structure and replacing the exposed molybdenum with cobalt.

This allowed the material to mimic the natural organic process bacteria use to turn atmospheric dinitrogen into ammonia in organisms, including in humans, who use ammonia to help liver function.

The inorganic process will allow ammonia to be produced anywhere it's needed as a small-scale adjunct to industry, which produces millions of tons of the chemical each year through the inorganic Haber-Bosch process.

The research is described in the Journal of the American Chemical Society.

"The Haber-Bosch process produces a lot of carbon dioxide and consumes a lot of energy," said co-lead author and Rice graduate student Xiaoyin Tian. "But our process uses electricity to trigger the catalyst. We can get that from solar or wind."

The researchers already knew that molybdenum disulfide had an affinity to bond with dinitrogen, a naturally occurring molecule of two strongly bonded nitrogen atoms that forms about 78% of Earth's atmosphere.

Computational simulations by Mingjie Liu, a research associate at Brookhaven National Laboratory, showed replacing some exposed molybdenum atoms with cobalt would enhance the compound's ability to facilitate dinitrogen's reduction to ammonia.

Lab tests at Rice showed this was so. The researchers assembled samples of the nanoscale material by growing defective molybdenum disulfide crystals on carbon cloth and adding cobalt. (The crystals are technically 2D but appear as a plane of molybdenum atoms with layers of sulfur above and below.) With current applied, the compound yielded more than 10 grams of ammonia per hour using 1 kilogram of catalyst.

"The scale is not comparable to well-developed industrials processes, but it can be an alternative in specific cases," said co-lead author Jing Zhang, a postdoctoral researcher at Rice. "It will allow the production of ammonia where there is no industrial plant, and even in space applications." He said lab experiments used dedicated feeds of dinitrogen, but the platform can as easily pull it from the air.

Lou said other dopants may allow the material to catalyze other chemicals, a topic for future studies. "We thought there was an opportunity here to take something we're very familiar with and try to do what nature has been doing for billions of years," he said. "If we design a reactor the right way, the platform can carry out its function without interruption."
-end-
Co-authors of the paper are Rice assistant research professor Hua Guo and graduate student Qiyi Fang; Qin Wu of Brookhaven National Laboratory; and Jiadong Zhou and Zheng Liu of Nanyang Technological University, Singapore.

The Welch Foundation and the U.S. Department of Energy Office of Science supported the research.

Read the abstract at https://pubs.acs.org/doi/10.1021/jacs.9b02501.

This news release can be found online at https://news.rice.edu/2019/11/25/ammonia-synthesis-made-easy-with-2d-catalyst/

Follow Rice News and Media Relations via Twitter @RiceUNews.

Related materials:

Lou Group: https://n3lab.rice.edu
Mingjie Liu: https://www.bnl.gov/cfn/people/staff.php?q=219
Rice Department of Materials Science and NanoEngineering: https://msne.rice.edu
George R. Brown School of Engineering: https://engineering.rice.edu

Images for download:

https://news-network.rice.edu/news/files/2019/11/1125_AMMONIA-1-WEB.jpg
Rice University graduate student Xiaoyin Tian, left, and postdoctoral researcher Jing Zhang led the effort to develop an inorganic catalyst for ammonia based on doped, two-dimensional molybdenum disulfide. (Credit: Lou Group/Rice University)

https://news-network.rice.edu/news/files/2019/11/1125_AMMONIA-2-WEB.jpg
Microscope images show cobalt-doped molybdenum disulfide as grown on a carbon cloth. The high-resolution transmission electron microscope image at right reveals the doped nanosheets, which facilitate the efficient electrochemical catalysis of ammonia. The process was developed for small-scale use by materials scientists at Rice University. (Credit: Lou Group/Rice University)

https://news-network.rice.edu/news/files/2019/11/1125_AMMONIA-3-WEB.jpg
The addition of cobalt atoms to fill vacancies in 2D molybdenum disulfide crystals enhances the material's ability to catalyze ammonia from dinitrogen. Rice University scientists have developed a "green" method for the small-scale synthesis of ammonia that uses less energy and produces less carbon dioxide than industrial processes. (Credit: Lou Group/Rice University)

Located on a 300-acre forested campus in Houston, Rice University is consistently ranked among the nation's top 20 universities by U.S. News & World Report. Rice has highly respected schools of Architecture, Business, Continuing Studies, Engineering, Humanities, Music, Natural Sciences and Social Sciences and is home to the Baker Institute for Public Policy. With 3,962 undergraduates and 3,027 graduate students, Rice's undergraduate student-to-faculty ratio is just under 6-to-1. Its residential college system builds close-knit communities and lifelong friendships, just one reason why Rice is ranked No. 1 for lots of race/class interaction and No. 4 for quality of life by the Princeton Review. Rice is also rated as a best value among private universities by Kiplinger's Personal Finance.

Rice University

Related Rice Articles:

3D camera earns its stripes at Rice
The Hyperspectral Stripe Projector captures spectroscopic and 3D imaging data for applications like machine vision, crop monitoring, self-driving cars and corrosion detection.
Climate change could increase rice yields
Research reveals how rice ratooning practices can help Japanese farmers increase rice yields.
Breeding new rice varieties will help farmers in Asia
New research shows enormous potential for developing improved short-duration rice varieties.
High-protein rice brings value, nutrition
A new advanced line of rice, with higher yield, is ready for final field testing prior to release.
Rice plants engineered to be better at photosynthesis make more rice
A new bioengineering approach for boosting photosynthesis in rice plants could increase grain yield by up to 27 percent, according to a study publishing January 10, 2019 in the journal Molecular Plant.
Can rice filter water from ag fields?
While it's an important part of our diets, new research shows that rice plants can be used in a different way, too: to clean runoff from farms before it gets into rivers, lakes, and streams.
Rice plants evolve to adapt to flooding
Although water is essential for plant growth, excessive amounts can waterlog and kill a plant.
Breeding better Brazilian rice
Rice production in Brazil is a multi-billion-dollar industry. It employs hundreds of thousands of people, directly and indirectly.
Breakthrough in battle against rice blast
Scientists have found a way to stop the spread of rice blast, a fungus that destroys up to 30% of the world's rice crop each year.
More rice, please: 13 rice genomes reveal ways to keep up with ever-growing population
Rice provides 20% of daily calories consumed globally. We will need more as population grows toward 9-10 billion by 2050.
More Rice News and Rice Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: The Power Of Spaces
How do spaces shape the human experience? In what ways do our rooms, homes, and buildings give us meaning and purpose? This hour, TED speakers explore the power of the spaces we make and inhabit. Guests include architect Michael Murphy, musician David Byrne, artist Es Devlin, and architect Siamak Hariri.
Now Playing: Science for the People

#576 Science Communication in Creative Places
When you think of science communication, you might think of TED talks or museum talks or video talks, or... people giving lectures. It's a lot of people talking. But there's more to sci comm than that. This week host Bethany Brookshire talks to three people who have looked at science communication in places you might not expect it. We'll speak with Mauna Dasari, a graduate student at Notre Dame, about making mammals into a March Madness match. We'll talk with Sarah Garner, director of the Pathologists Assistant Program at Tulane University School of Medicine, who takes pathology instruction out of...
Now Playing: Radiolab

What If?
There's plenty of speculation about what Donald Trump might do in the wake of the election. Would he dispute the results if he loses? Would he simply refuse to leave office, or even try to use the military to maintain control? Last summer, Rosa Brooks got together a team of experts and political operatives from both sides of the aisle to ask a slightly different question. Rather than arguing about whether he'd do those things, they dug into what exactly would happen if he did. Part war game part choose your own adventure, Rosa's Transition Integrity Project doesn't give us any predictions, and it isn't a referendum on Trump. Instead, it's a deeply illuminating stress test on our laws, our institutions, and on the commitment to democracy written into the constitution. This episode was reported by Bethel Habte, with help from Tracie Hunte, and produced by Bethel Habte. Jeremy Bloom provided original music. Support Radiolab by becoming a member today at Radiolab.org/donate.     You can read The Transition Integrity Project's report here.