High reaction rates even without precious me…

High reaction rates even without precious metals

Non-precious metal nanoparticles could one day replace expensive catalysts for hydrogen production. However, it is often difficult to determine what reaction rates they can achieve, especially when it comes to oxide particles. This is because the particles must be attached to the electrode using a binder and conductive additives, which distort the results. With the aid of electrochemical analyses of individual particles, researchers have now succeeded in determining the activity and substance conversion of nanocatalysts made from cobalt iron oxide—without any binders. The team led by Professor Kristina Tschulik from Ruhr-Universität Bochum reports together with colleagues from the University of Duisburg-Essen and from Dresden in the Journal of the American Chemical Society, published online on 30 May 2019.

“The development of non-precious metal catalysts plays a decisive role in realising the energy transition as only they are cheap and available in sufficient quantities to produce the required amounts of renewable fuels,” says Kristina Tschulik, a member of the Cluster of Excellence Ruhr Explores Solvation (Resolv). Hydrogen, a promising energy source, can thus be acquired by splitting water into hydrogen and oxygen. The limiting factor here has so far been the partial reaction in which oxygen is produced.

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Pantry ingredients can help grow carbon nano…

Pantry ingredients can help grow carbon nanotubes

Baking soda, table salt, and detergent are surprisingly effective ingredients for cooking up carbon nanotubes, researchers at MIT have found.

In a study published this week in the journal Angewandte Chemie, the team reports that sodium-containing compounds found in common household ingredients are able to catalyze the growth of carbon nanotubes, or CNTs, at much lower temperatures than traditional catalysts require.

The researchers say that sodium may make it possible for carbon nanotubes to be grown on a host of lower-temperature materials, such as polymers, which normally melt under the high temperaturesneeded for traditional CNT growth.

“In aerospace composites, there are a lot of polymers that hold carbon fibers together, and now we may be able to directly grow CNTs on polymer materials, to make stronger, tougher, stiffer composites,” says Richard Li, the study’s lead author and a graduate student in MIT’s Department of Aeronautics and Astronautics. “Using sodium as a catalyst really unlocks the kinds of surfaces you can grow nanotubes on.”

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Metal mediated radical polymerizations are a f…

Metal mediated radical polymerizations are a form of radical polymerizations which are mediated, rather than initiated, by metal catalysts (cobalt and copper based catalysts are particularly common). These mediators help control the rates of the reactions, and thus the structure and molecular weight of the resulting polymers. Atom transfer radical polymerizations are often mediated by metal complexes. 

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Catalytic chain transfer ( 2 ) is a process fo…

Catalytic chain transfer ( 2 ) is a process for modifying radical polymerization reactions to allow for better control of the resulting polymers. It is most often used to create shorter chain polymers or low molecular weight polymers. Complexes of Co, Cr, Fe, Mo, and other metals are common catalysts for this process. 

Image source.

Artificial photosynthesis transforms carbon di…

Artificial photosynthesis transforms carbon dioxide into liquefiable fuels

Chemists at the University of Illinois have successfully produced fuels using water, carbon dioxide and visible light through artificial photosynthesis. By converting carbon dioxide into more complex molecules like propane, green energy technology is now one step closer to using excess CO2 to store solar energy – in the form of chemical bonds – for use when the sun is not shining and in times of peak demand.

[…]

Plants use sunlight to drive chemical reactions between water and CO2 to create and store solar energy in the form of energy-dense glucose. In the new study, the researchers developed an artificial process that uses the same green light portion of the visible light spectrum used by plants during natural photosynthesis to convert CO2 and water into fuel, in conjunction with electron-rich gold nanoparticles that serve as a catalyst. The new findings are published in the journal Nature Communications.

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Coordination polymerization ( 2 ) is a reactio…

Coordination polymerization ( 2 ) is a reaction wherein polymerization occurs through coordination at the metallic center of catalytic transition metal salts and complexes. The most common catalysts are Ziegler-Natta catalysts, shown above. This type of polymerization is used for polymers produced from vinyl monomers, such as polyethylene. 

Image sources: ( 1 ) ( 2 )

Methane-consuming bacteria could be the futu…

Methane-consuming bacteria could be the future of fuel

Discovery illuminates how bacteria turn methane gas into liquid methanol

Known for their ability to remove methane from the environment and convert it into a usable fuel, methanotrophic bacteria have long fascinated researchers. But how, exactly, these bacteria naturally perform such a complex reaction has been a mystery.

Now an interdisciplinary team at Northwestern University has found that the enzyme responsible for the methane-methanol conversion catalyzes this reaction at a site that contains just one copper ion.

This finding could lead to newly designed, human-made catalysts that can convert methane – a highly potent greenhouse gas – to readily usable methanol with the same effortless mechanism.

“The identity and structure of the metal ions responsible for catalysis have remained elusive for decades,” said Northwestern’s Amy C. Rosenzweig, co-senior author of the study. “Our study provides a major leap forward in understanding how bacteria methane-to-methanol conversion.”

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Taming defective porous materials for robust…

Taming defective porous materials for robust and selective heterogeneous catalysis

The production of 1-butene via ethylene dimerization is one of the few industrial processes that employs homogeneous catalysis due to its high selectivity, despite the massive amounts of activators and solvents required. Now, a new paper by the University of the Basque Country (UPV/EHU), in collaboration with the López group at the Institute of Chemical Research of Catalonia (ICIQ) and RTI International, shows a more sustainable alternative via metal-organic frameworks (MOFs), a family of porous materials formed by metallic nodes connected through organic ligands.

The scientists demonstrate that tailored MOFs under condensation regimes catalyze the ethylene dimerization to 1-butene with high selectivity and stability in the absence of activators and solvent. The research, published in Nature Communications, opens new avenues to develop robust heterogeneous catalysts for a wide variety of gas-phase reactions.

The researchers engineered defects in the MOF (Ru)HKUST-1 without compromising the framework structure via two strategies: a conventional ligand exchange approach during MOF synthesis, and a pioneering post-synthetic thermal approach. The researchers then characterized the defects, which have been shown to be catalytically active for ethylene dimerization.

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cenchempics: Polymer Tesseract Chris Thomson f…

cenchempics:

Polymer Tesseract

Chris Thomson found this glowing material after filtering the products of a catalytic reaction and couldn’t help but take a photo of it because it resembled the Tesseract featured in the Avengers film franchise. The material, however, does not contain a single Infinity Stone. It’s made up of a bunch of polystyrene beads decorated with a benzothiadiazole derivative that fluoresces under ultraviolet light. Thomson, a PhD student at Heriot-Watt University and the Centre for Doctoral Training in Critical Resource Catalysis under the supervision of Filipe Vilela and Ai-Lan Lee, is looking for catalysts that can be used in flow chemistry to replace rare-earth catalysts currently used in organic synthesis. Plus, the bead-supported catalysts he makes are easy to separate from a reaction, which means they could be recycled. —Manny Morone

Submitted by Chris Thomson

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Cleaner, cheaper ammonia: Cheaper fertilizer

Cleaner, cheaper ammonia: Cheaper fertilizer

Researchers dramatically clean up ammonia production and cut costs

Ammonia – a colorless gas essential for things like fertilizer – can be made by a new process which is far cleaner, easier and cheaper than the current leading method. UTokyo researchers use readily available lab equipment, recyclable chemicals and a minimum of energy to produce ammonia. Their Samarium-Water Ammonia Production (SWAP) process promises to scale down ammonia production and improve access to ammonia fertilizer to farmers everywhere.

In 1900, the global population was under 2 billion, whereas in 2019, it is over 7 billion. This population explosion was fueled in part by rapid advancements in food production, in particular the widespread use of ammonia-based fertilizers. The source of this ammonia was the Haber-Bosch process, and though some say it’s one of the most significant achievements of all time it comes with a heavy price.

The Haber-Bosch process only converts 10 percent of its source material per cycle so needs to run multiple times to use it all up. One of these source materials is hydrogen (H2) produced using fossil fuels. This is chemically combined with nitrogen (N2) at temperatures of about 400-600 degrees Celsius and pressures of about 100-200 atmospheres, also at great energy cost. Professor Yoshiaki Nishibayashi and his team from the University of Tokyo’s Department of Systems Innovation hope to improve the situation with their SWAP process.

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