Carbon dioxideA team of researchers from the University of Toronto is looking to give wasted materials new value by developing a new catalyst that could help recycle carbon dioxide into plastic.

According to a new study, the researchers have successfully used a new technique to efficiently convert carbon dioxide to ethylene, which can then be processed to make polyethylene, the most common plastic used in making packaging, bottles, and toys.

By using a copper catalyst, the team was able to achieve the desired result of ethylene production. However, controlling the catalyst was one of the technological challenges the team had to overcome.

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Many areas of the United States are at risk for nitrate and nitrite contamination of drinking water due to overuse of agricultural fertilizers. Click to enlarge.
Image: USGS

Researchers have found a catalyst that can clean toxic nitrates from drinking water by converting them into air and water.

“Nitrates come mainly from agricultural runoff, which affects farming communities all over the world,” says lead study scientist Michael Wong, a chemical engineer at Rice University.

“Nitrates are both an environmental problem and health problem because they’re toxic. There are ion-exchange filters that can remove them from water, but these need to be flushed every few months to reuse them, and when that happens, the flushed water just returns a concentrated dose of nitrates right back into the water supply,” he explains.

Wong’s lab specializes in developing nanoparticle-based catalysts, submicroscopic bits of metal that speed up chemical reactions. In 2013, his group showed that tiny gold spheres dotted with specks of palladium could break apart nitrites, the more toxic chemical cousins of nitrates.

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Transforming Carbon Dioxide

Carbon dioxideCarbon dioxide accounts for over 80 percent of all greenhouse gas emissions. For many, carbon dioxide emissions account for significant environmental issues, but for researchers like Haotian Wang of Harvard University, carbon dioxide could be the perfect raw material.

According to a new study, Wang and his team are well on the way to developing a system that uses renewable electricity to electrochemically transform carbon dioxide into carbon monoxide. The carbon monoxide could then be used in a host of industrial processes, such as plastics production, creating hydrocarbon products, or as a fuel itself.

This from Harvard University:

The energy conversion efficiency from sunlight to CO can be as high as 12.7%, more than one order of magnitude higher than natural photosynthesis.

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Water splittingScientists have created a single catalyst that could simplify the process of splitting water into hydrogen and oxygen to produce clean energy.

The electrolytic film is a three-layer structure of nickel, graphene, and a compound of iron, manganese, and phosphorus. The foamy nickel gives the film a large surface, the conductive graphene protects the nickel from degrading and the metal phosphide carries out the reaction.

The team of scientists developed the film to overcome barriers that usually make a catalyst good for producing either oxygen or hydrogen, but not both simultaneously.

“Regular metals sometimes oxidize during catalysis,” says Kenton Whitmire, a professor of chemistry at Rice University. “Normally, a hydrogen evolution reaction is done in acid and an oxygen evolution reaction is done in base. We have one material that is stable whether it’s in an acidic or basic solution.”

The discovery builds upon the researchers’ creation of a simple oxygen-evolution catalyst revealed earlier this year. In that work, the team grew a catalyst directly on a semiconducting nanorod array that turned sunlight into energy for solar water splitting.

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Achieving a More Efficient Catalyst

Nanoporous goldA new study out of Lawrence Livermore National Laboratory shows that catalysts derived from nano-structured materials are as good as gold.

According to the study, led by past ECS member Juergen Biener, restructuring nanoporous gold alloys result in more efficient catalysts.

Nano-structured materials have shown promising qualities for improving catalyst activity and selectivity, but little is known about the structural changes that the materials undergo that can create or prevent efficient catalyst function.

This from LLNL:

The team used ozone-activated silver-gold alloys in the form of nanoporous gold (npAu) as a case study to demonstrate the dynamic behavior of bi-metallic systems during activation to produce a functioning catalyst. Nanoporous gold, a porous metal, can be used in electrochemical sensors, catalytic platforms, fundamental structure property studies at the nanoscale and tunable drug release. It also features high effective surface area, tunable pore size, well-defined conjugate chemistry, high electrical conductivity and compatibility with traditional fabrication techniques.

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Catalysts

Image: MIT

The future of renewable energy heavily depends on energy storage technologies. At the center of these technologies are oxygen-evaluation reactions, which make possible such processes as water splitting, electrochemical carbon dioxide reduction, and ammonia production.

However, the kinetics of the oxygen-evolution reactions tend to be slow. But metal oxides involved in this process have catalytic activities that vary over several orders of magnitude, with some exhibiting the highest such rates reported to date. The origins of these activates are not well-understood by the scientific community.

A new study from MIT, led by 2016 winner of the Battery Division Research Award, Yang Shao-Horn, shows that in some of these catalysts, the oxygen does not only come from surrounding water molecules – some actually come from within the crystal lattice of the catalyst material itself.

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CatalystAn interdisciplinary team made up of researchers from Stanford University and the U.S. Department of Energy’s SLAC National Accelerator Laboratory recently developed a new catalyst that carries out a solar-powered reaction 100 times faster than ever before.

Additionally, the catalyst’s performance improves as time goes on and it can stand up to intense, acidic conditions. In creating the catalyst, the researchers used less iridium than would typically be used, potentially lowering the cost to produce hydrogen or carbon-based fuels that could power a range of renewable, sustainable alternatives.

This from SLAC National Accelerator Laboratory:

The discovery of the catalyst – a very thin film of iridium oxide layered on top of strontium iridium oxide – was the result of an extensive search by three groups of experts for a more efficient way to accelerate the oxygen evolution reaction, or OER, which is half of a two-step process for splitting water with sunlight.

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Fuel cells have been receiving a lot of attention in the scientific domain as one of the most promising alternative energy sources. When applying fuel cell technology to both the grid and automobiles, one issue is persistent: cost. Researchers at Argonne National Laboratory (ANNL) have been looking for a way to combat the price issues. Now, a team of researchers led by ECS member Di-Jia Liu have found a potential way to utilize fuel cells without the high cost of development and commercialization.

A New Catalyst

The team’s development revolves around the notion of using naturally abundant materials without sacrificing efficiency. Current, fuel cells work off a platinum catalyst, which is both expensive and scarce. The new catalyst eliminates the need for the precious material, all while demonstrating performance rates comparable to that of a platinum catalyst.

The scientists developed the new catalyst via the synthesis of a highly efficient, nanofibrous non-precious metal catalyst. If this technique proves to be commercially viable, it transition into automotive technology and extend the range of electric vehicles and potentially eliminate the need for charging.

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Catalysts Move Away from Platinum

The new catalyst combines platinum and palladium, resulting in high efficiency levels and lower cost.Image: Mavrikakis group, UW-Madison

The new catalyst combines platinum and palladium, resulting in high efficiency levels and lower cost.
Image: Mavrikakis group, UW-Madison

In recent years, platinum has been the leading material in the energy industry. However, platinum is both expensive and scarce.

In order to boost alternative energy solutions, researchers have been searching for a substitute for platinum that will allow for cheaper and equally efficient energy technology.

In order to do this, a team from the University of Wisconsin-Madison and Georgia Institute of Technology are focusing on a new catalyst that combines the more expensive platinum with the less expensive palladium.

This from University of Wisconsin-Madison:

This not only reduces the need for platinum but actually proves significantly more catalytically active than pure platinum in the oxygen reduction reaction, a chemical process key to fuel cell energy applications. The palladium-platinum combination also proves more durable, compounding the advantage of getting more reactivity with less material. Just as importantly, the paper offers a way forward for chemical engineers to design still more new catalysts for a broad range of applications by fine-tuning materials on the atomic scale.

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