Discover Top Posts Tagged with #cerium oxide

High-performance cerium oxide thermal switches improve heat flow control

Thermal switches, which electrically control heat transfer, are essential for the advancement of sophisticated thermal management systems. Historically, electrochemical thermal switches have been constrained by suboptimal performance, which impedes their extensive utilization in the electronics, energy, and waste heat recovery sectors. A research team led by Professor Hiromichi Ohta of the Research Institute for Electronic Science, Hokkaido University employed a novel approach of using cerium oxide (CeO2) thin films as the active material in thermal switches, providing a highly efficient and sustainable alternative. Their findings have been published in Science Advances. The research team showed that CeO2-based thermal switch performance can exceed prior benchmarks. "The novel device features an on/off thermal conductivity ratio of 5.8 and a thermal conductivity (κ)-switching width of 10.3 W/m·K, establishing a new benchmark for electrochemical thermal switches," Ohta explains.

Sugar-loving bacteria cause cavities, but killing all bacteria in the mouth isn’t healthy because some of them have beneficial effects, including aiding digestion. A University of Illinois at Chicago (UIC) team has discovered that a nanoparticle coating could prevent cavities without harming good bacteria. When harmful bacteria such as Streptococcus...

Fine tuning materials for energy storage using architectural design and structural engineering

Energy researchers from the University of New South Wales (UNSW) have reported progress using controlled architectural design and structural engineering as a method to fine-tune materials to have simultaneous high power and high energy density for electrochemical storage in portable devices.

The designed material that consists of nanoflakes of cerium oxide synthesized to a consistent thickness and implanted with molybdenum ions at ANSTO's Centre for Accelerator Science has demonstrated promising characteristics for use as an intercalation pseudocapacitor.

Dr. Pramod Koshy, Dr. Sajjad S Mofarah, Mr. Xiaroran Zheng and associates in the School of Materials Science and Engineering at UNSW, the Solid State Physics Laboratory in Bangladesh and ANSTO have reported on the fine-tuning of oxygen vacancy ordering and channel formation in cerium oxide implanted with molybdenum ions to achieve intercalated pseudocapacitance.

The results have been published in the journal ACS Applied Materials and Interfaces.

Cerium oxide nanoparticles may improve hepatocellular carcinoma prognosis

Hepatocellular carcinoma is the most common liver cancer and ranks third in the world in terms of mortality. Its appearance is related to the hepatitis B and C viruses, alcoholism, metabolic diseases of the liver and exposure to certain toxins. Although its molecular mechanisms have been described in detail, no effective treatment is currently available after the early stages of the disease. When ablation is no longer possible, the best therapeutic approaches fail to stop the progression of the cancer. According to the journal Hepatology, this could change thanks to an experimental treatment based on cerium oxide nanoparticles on which the Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) and the Catalan Institute of Nanoscience and Nanotechnology (ICN2) have been jointly working for some time.

The paper explains how, thanks to their antioxidant and anti-inflammatory properties, cerium oxide nanoparticles have been able to partially reverse the cellular mechanisms involved in tumor progression and have managed to significantly increase survival in a rat animal model. The last authors of the study are Prof. Wladimiro Jiménez at the Hospital Clínic of Barcelona and ICREA Prof. Víctor F. Puntes. The first author is Guillermo Fernández-Varo, member of the IDIBAPS research group mentioned above and of the CIBER on Liver and Digestive Diseases (CIBERehd).

Crystalline 'nanobrush' clears way to advanced energy and information tech

A team led by the Department of Energy's Oak Ridge National Laboratory synthesized a tiny structure with high surface area and discovered how its unique architecture drives ions across interfaces to transport energy or information. Their "nanobrush" contains bristles made of alternating crystal sheets with vertically aligned interfaces and plentiful pores.

"These are major technical accomplishments and may prove useful in advancing energy and information technologies," said ORNL's Ho Nyung Lee, who led the study published in Nature Communications. "This is an excellent example of work that is only feasible with the unique expertise and capabilities available at national labs."

The team's researchers hail from DOE national labs Oak Ridge and Argonne and Massachusetts Institute of Technology, or MIT, University of South Carolina, Columbia, and University of Tennessee, Knoxville.

Common 'oxygen sponge' catalyst soaks up hydrogen too, neutron spectroscopy reveals

Having the right tool for the job enabled scientists at the Department of Energy's Oak Ridge National Laboratory and their collaborators to discover that a workhorse catalyst of vehicle exhaust systems -- an "oxygen sponge" that can soak up oxygen from air and store it for later use in oxidation reactions -- may also be a "hydrogen sponge."

The finding, published in the Journal of the American Chemical Society, may pave the way for the design of more effective catalysts for selective hydrogenation reactions. Selective hydrogenation is the key to producing valuable chemicals, for example, turning triple-bonded hydrocarbons called alkynes selectively into double-bonded alkenes -- starting materials for the synthesis of plastics, fuels and other commercial products.

"Understanding how molecular hydrogen interacts with ceria [cerium oxide, CeO2], however, is a big challenge, as no regular technique can 'see' the light H atom. We turned to inelastic neutron spectroscopy, a technique that is very sensitive to hydrogen," said ORNL chemist Zili Wu. At ORNL's Spallation Neutron Source (SNS), a DOE Office of Science User Facility, a neutron beam line called VISION probed vibrational signals of atomic interactions and generated spectra describing them. "Because neutron spectroscopy could 'see' hydrogen due to its large neutron scattering cross-section, it succeeded where optical spectroscopy techniques failed and enabled the first direct observations of cerium hydrides both on the surface and in the bulk of a cerium oxide catalyst," Wu said.

Dynamic catalytic converters for clean air in the city

Reducing pollutant emission of vehicles and meeting stricter exhaust gas standards are major challenges when developing catalytic converters. A new concept might help to efficiently treat exhaust gases after the cold start of engines and in urban traffic and to reduce the consumption of expensive noble metal. It is based on the interaction between platinum and the cerium oxide carrier to control catalytic activity by short-term changes of the engine's operation mode, researchers report in the journal Angewandte Chemie.

Thanks to its good catalytic properties, platinum is often applied in catalytic converters of vehicles. Presently, about 60% of European platinum trade are used for this purpose. Using a diesel oxidation catalytic converter (DOC), in which afterburning of hydrocarbons and carbon monoxide takes place, the scientists of Karlsruhe Institute of Technology (KIT) and their partners found that the particle size and oxidation state of the platinum component during operation can be modified specifically. Interactions between the carrier material and the applied noble metal play an important role. The results reflect a highly dynamic catalytic converter surface that reacts extremely sensitively to external impacts, such as exhaust gas composition. The researchers present ways of using this dynamics to improve catalytic converters.

Stanford scientists use nanotechnology to boost the performance of key industrial catalyst

A tiny amount of squeezing or stretching can produce a big boost in catalytic performance, according to a new study led by scientists at Stanford University and SLAC National Accelerator Laboratory.

[...]

The discovery, published May 18 in Nature Communications, focuses on an industrial catalyst known as cerium oxide, or ceria, a spongy material commonly used in catalytic converters, self-cleaning ovens and various green-energy applications, such as fuel cells and solar water splitters.

"Ceria stores and releases oxygen as needed, like a sponge," said study co-author Will Chueh, an assistant professor of materials science and engineering at Stanford and a faculty scientist at SLAC. "We discovered that stretching and compressing ceria by a few percent dramatically increases its oxygen storage capacity. This finding overturns conventional wisdom about oxide materials and could lead to better catalysts."

Common 'oxygen sponge' catalyst soaks up hydrogen too, neutron spectroscopy reveals

#cerium oxide

Trending Tags

Recently Viewed Tags

#cerium oxide