Researchers reveal in-situ manipulation of active Au-TiO2 interface
2021-01-28
(Press-News.org) An international joint research team from the Shanghai Advanced Research Institute of the Chinese Academy of Sciences, along with Zhejiang University and the Technical University of Denmark, reported an in-situ strategy to manipulate interfacial structure with atomic precision during catalytic reactions. Results were published in the latest issue of Science.
The interface between nanoparticles and substrates plays a critical role in heterogeneous catalysis because most active sites are located at the perimeter of the interface. It is generally believed that this interface is immobile and unchangeable, thus can hardly be adjusted in reactive environments. As a result, it has been challenging to promote catalytic activity through precise control of the interfacial structure.
In this study, the scientists first used environmental transmission electron microscopy to directly visualize the epitaxial rotation of gold nanoparticles on titanium dioxide (TiO2) surfaces during CO oxidation at the atomic level. A perfect epitaxial relationship was observed between Au nanoparticles and TiO2 (001) surfaces under an O2 environment in real time.
Theoretical calculations including density functional theory calculations and thermodynamics analysis were then carried out, indicating that the epitaxial orientation could be induced by changing O2 adsorption coverage at the perimeter interface. The Au nanoparticle was more stable with adsorption of more O2 molecules at the Au-TiO2 interface, but became less stable with the consumption of O2 with CO.
To exploit the promoted activity of Au-TiO2 interface, researchers conducted additional top-view observations and found that this configuration remained unchanged when cooling from 500 °C to 20 °C in CO and O2 reactive environments, showing the rotation of the Au nanoparticle was also temperature dependent in reaction conditions.
Taking advantage of the reversible and controllable rotation of the Au nanoparticle, the scientists achieved in-situ manipulation of the active Au-TiO2 interface at the atomic level by changing gas and temperature.
This study sheds light on real-time manipulation of catalytic interface structure in reaction conditions at the atomic scale, which may inspire future approaches to real-time design of the catalytic interface under operating conditions.
INFORMATION:
[Attachments] See images for this press release:
ELSE PRESS RELEASES FROM THIS DATE:
2021-01-28
The emergence of SARS-CoV-2 virus variants that are adding twists in the battle against COVID-19 highlight the need for better genomic monitoring of the virus, says Katia Koelle, associate professor of biology at Emory University.
"Improved genomic surveillance of SARS-CoV-2 across states would really help us to better understand how the virus causing the pandemic is evolving and spreading in the United States," Koelle says. "More federal funding is needed, along with centralized standards for sample collection and genetic sequencing. Researchers need access to such metadata to better track how the virus is spreading geographically, and to identify any new variants ...
2021-01-28
BOSTON -- Routine screening of asymptomatic health care personnel (HCP) in the absence of confirmed exposures to COVID-19 is not a recommended strategy for preventing transmission of the coronavirus causing the current global pandemic, according to a new review co-authored by an infectious disease specialist at Massachusetts General Hospital (MGH). The review, published in Infection Control & Hospital Epidemiology, found that such testing is unlikely to affect the transmission of SARS-CoV-2 in health care settings and could even have unintended negative consequences.
Many universities, sports leagues and other institutions require individuals in their organization to undergo routine testing for COVID-19, whether or not they are experiencing symptoms. Current public ...
2021-01-28
When thick, the surface layer of the ocean acts as a buffer to extreme marine heating--but a new study from the University of Colorado Boulder shows this "mixed layer" is becoming shallower each year. The thinner it becomes, the easier it is to warm. The new work could explain recent extreme marine heatwaves, and point at a future of more frequent and destructive ocean warming events as global temperatures continue to climb.
"Marine heatwaves will be more intense and happen more often in the future," said Dillon Amaya, a CIRES Visiting Fellow and lead author on the study out ...
2021-01-28
Counties with a greater number of cannabis dispensary storefronts experience reduced numbers of opioid-related deaths relative to other locales, a recent University of California, Davis, study has found. This is the first study to examine the association between active cannabis dispensary operations -- both medical and recreational -- and opioid-related mortality rates at the county level, suggesting that providing alternative pain management could improve public health outcomes, researchers said.
"While the associations documented cannot be assumed to be causal, they suggest a potential relationship between increased prevalence of medical and recreational cannabis dispensaries and reduced opioid-related ...
2021-01-28
WASHINGTON --- Pancreatic cancer, one of the most lethal of all cancers, is capable of evading attacks by immune cells by changing its microenvironment so that the immune cells suppress, rather than support, an attack on the tumor. The scientists also found that that some of the mediators of this suppressive response, including a protein called STAT1, represent potential therapeutic targets that could be used to reverse this evasion and point to possible treatment opportunities.
The finding appears January 28, 2021, in Cancer Immunology Research.
"This ...
2021-01-28
The origin of flowering plants famously puzzled Charles Darwin, who described their sudden appearance in the fossil record from relatively recent geological times as an "abominable mystery". This mystery has further deepened with an inexplicable discrepancy between the relatively recent fossil record and a much older time of origin of flowering plants estimated using genome data.
Now a team of scientists from Switzerland, Sweden, the UK, and China may have solved the puzzle. Their results show flowering plants indeed originated in the Jurassic or earlier, that is millions of years earlier than their oldest undisputed fossil evidence, according to a new study published in the scientific journal Nature Ecology & Evolution. The lack of older ...
2021-01-28
Although loggerhead sea turtles return to the same beach where they hatched to lay their eggs, a new study by a USF professor finds individual females lay numerous clutches of eggs in locations miles apart from each other to increase the chance that some of their offspring will survive.
A study published in the journal "Scientific Reports" found that some females lay as many as six clutches as far as six miles apart during the same breeding season.
"Nesting females don't lay all their eggs in one basket. Their reproductive strategy is like investing in a mutual fund. Females divide their resources among many stocks rather than investing everything in a single stock," said Deby Cassill, biology professor ...
2021-01-28
Researchers with the Kansas City Veterans Affairs Medical Center and North Dakota State University have designed a new way to deliver pancreatic cancer drugs that could make fighting the disease much easier. Encapsulating cancer drugs in nanoparticles shows potential to target tumors more effectively and avoid danger to other parts of the body.
The study results appeared in the Jan. 4, 2021, issue of the journal Molecular Pharmaceutics.
Study author Dr. Sushanta Banerjee, a researcher with the Kansas City VA and University of Kansas medical centers, explains that this technology has the potential to drastically improve Veterans' cancer care. "Veteran health care will benefit immensely from such therapeutic models, as they are ...
2021-01-28
UPTON, NY--A team of researchers led by chemists at the U.S. Department of Energy's (DOE) Brookhaven National Laboratory has identified new details of the reaction mechanism that takes place in batteries with lithium metal anodes. The findings, published today in Nature Nanotechnology, are a major step towards developing smaller, lighter, and less expensive batteries for electric vehicles.
Recreating lithium metal anodes
Conventional lithium-ion batteries can be found in a variety of electronics, from smartphones to electric vehicles. While lithium-ion batteries have enabled the widespread use of many technologies, they still face challenges in powering electric vehicles over ...
2021-01-28
URBANA, Ill. - Getting nutrition right during a dairy cow's dry period can make a big difference to her health and the health of her calf. But it's also a key contributor to her milk yield after calving. New research from the University of Illinois shows diets containing consistent energy levels and the rumen-boosting supplement monensin may be ideal during the dry period.
"Many producers use a 'steam up' approach where you gradually increase the energy intake during the dry period to help adjust the rumen and adapt the cow to greater feed intakes after calving. Our work has shown that's really of questionable benefit for many farms, and it may be safer to just ...
LAST 30 PRESS RELEASES:
[Press-News.org] Researchers reveal in-situ manipulation of active Au-TiO2 interface
