A research group in Japan has successfully developed a “nanoporous super multi-element catalyst” (1) that contains 14 elements (2) which are mixed uniformly at the atomic level and used as a catalyst. The new catalyst was found to show excellent properties as an electrode material for water electrolysis due to the multi-element superposition effect (cocktail effect). The researchers are expecting it will be developed into an omnipotent and versatile catalyst in the future.

The nanoporous super multi-element catalyst promotes the water splitting from water to hydrogen and oxygen. Image Credit and ©: Takeshi Fujita, Kochi University of Technology. Click image for the largest view.

A high-entropy alloy composed of 10 or more elements may act as a catalyst to exhibit “omnipotency and versatility” because it is able to freely modify its morphology and become active according to the reaction field. However, so far, it has not been easy to produce entropy alloys composed of more than 10 elements. The reason is the existence of combinations of some elements that are hard to be mixed, like water and oil.

The joint research group is led by Research Associate Cai ZeXing and Professor Takeshi Fujita at School of Environmental Science and Engineering, Kochi University of Technology, and Professor Masahiro Miyauchi at School of Materials Science and Engineering, Tokyo Institute of Technology. The team’s research paper has been published in the journal Chemical Science.

The nanoporous super multi-element catalyst can be made from an Al alloy containing 14 elements dealloyed by an alkaline solution such as NaOH. Image Credit and ©: Takeshi Fujita, Kochi University of Technology. Click image for the largest view.

The team has developed a “nanoporous super multi-element catalyst” by a method called de-alloying(3) via the selective corrosion and elusion of a specified element from the alloy. The fabrication method is simple: an aluminum alloy containing 14 elements is prepared, and the nanoporous super multi-element catalyst is manufactured by preferential dissolution of aluminum using an alkaline solution.

The team has found by using this method, while creating a nanoporous structure with a large specific surface area (surface area per unit mass of material) with a pore size of about 5 nanometers, elements other than aluminum that do not dissolve in the alkaline solution are accumulated to be aggregated in the form of a solid solution alloy(4) in which the 14 elements are uniformly distributed at the atomic level.

The nanoporous super multi-element catalyst was also found to show excellent properties as an electrode material for water electrolysis due to the multi-element superposition effect (cocktail effect) (5). As this catalyst contains many different elements, it is expected that in the future, it will be developed into an omnipotent and versatile catalyst.

Notes:
(1) Nanoporous super multi-element catalyst:
A catalyst wherein at least 10 elements are uniformly distributed in a sponge structure (porous structure comprising nanosized pores) in which the nanosized pores are randomly connected.
(2) The 14 elements are:
Aluminum (Al), Silver (Ag), Gold (Au), Cobalt (Co), Copper (Cu), Iron (Fe), Iridium (Ir), Molybdenum (Mo), Nickel (Ni), Palladium (Pd), Platinum (Pt), Rhodium (Rh), Ruthenium (Ru), Titanium (Ti).
(3) De-alloying:
A method of selectively eroding and eluting specific elements from an alloy. It is also called selective corrosion.
(4) Solid solution alloy:
An alloy in which two or more elements are mutually melted in each other to form a uniform solid phase.
(5) Multi-element superposition effect (cocktail effect):
Manifestation of a characteristic feature resulting from nonlinear interaction between various constituent atoms. It is expected to reveal particular and outstanding catalytic properties so far inexistent in conventional alloy catalysts.

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The innovative and creative thinking, learned perhaps from Chindogu, the Japanese art of “unuseless inventions” and Wacky Inventions, may have really paid off with this team. The selective corrosion effect taken up to a “De-alloying” level is quite impressive used as a product creation process. Congratulations, indeed.

The team has also shown that the catalyst field is growing out into new territory and becoming ever more useful in processes today and in ways yet to be thought of tomorrow. More is sure to come. Its a very exciting time in chemistry.

A Tohoku University research team has developed liquid-sulfur/sulfide composite cathodes that enable high-rate magnesium batteries. Magnesium rechargeable batteries show immense promise for a greener future because of their energy density, safety, and cost. But the lack of high-performance cathode materials has impeded their development.

Magnesium rechargeable batteries (MRBs), where high-capacity Mg metal is used as the anode material, are promising candidates for next-generation batteries. Like their lithium-ion counterparts, transition metal oxides are the staple cathode materials in MRBs.

Schematic illustration showing the concept of this work. Liquid-sulfur/sulfide composite materials fabricated by electrochemical oxidation of metal sulfides can work as high-performance cathode materials for magnesium rechargeable batteries. Image Credit: ©Kohei Shimokawa, Tohoku University. Click image for the largest view.

But the slow diffusion of Mg ions inside the oxides poses a serious problem. To overcome this, some researchers have explored sulfur-based materials. But sulfur-based cathodes for MRBs have severe limitations: low electronic conductivity, sluggish Mg diffusion in solid Mg-S compounds, and dissolubility of polysulfides into electrolytes, which results in low-rate capability and poor cyclability.

Now, a research team that included Tohoku University’s Dr. Shimokawa and Professor Ichitsubo has developed liquid-sulfur/sulfide composite cathodes enabling high-rate magnesium batteries.

Their paper has been published in the Journal of Materials Chemistry A.

The liquid-sulfur/sulfide composite materials can be spontaneously fabricated by electrochemically oxidizing metal sulfides, such as iron sulfide, in an ionic liquid electrolyte at 150. The composite material showed high performance in capacity, potential, cyclability, and rate capability.

The researchers achieved the discharge capacity of ~900 mAh/g at a high current density of 1246 mA/g based on the mass of active sulfur. In addition, they revealed that the discharge potential was enhanced by utilizing non-equilibrium sulfur formed by fast charging processes.

This material allowed for a stable cathode performance at 150 for more than 50 cycles. Such a high cyclability could be attributed to the following points: high structural reversibility of the liquid state active material, low solubility of polysulfides into the ionic liquid electrolyte, and high utilization ratio of sulfur due to its adhesion to conductive sulfide particles that form a porous morphology during the synthesis of the composite materials.

Despite the researchers’ progress, several problems remain. “We need electrolytes that are compatible with both the cathode and anode materials because the ionic liquid used in this work passivates the Mg-metal anode,” said Shimokawa. “In the future, it is important to develop new electrochemically stable electrolytes to make MRBs more practical for widespread use.”

Although MRBs are still in the development stage, the research team is hopeful their work provides a new way to utilize liquid sulfur as high-rate cathode materials for MRBs. “This would boost the improvement of sulfur-based materials for achieving high-performance next-generation batteries,” added Shimokawa.

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One of the most desirable battery chemistries is magnesium based. Magnesium is cheap compared to lithium and offers more theoretical performance. That’s why magnesium battery news is so interesting.

Lithium isn’t going to disappear though, The metal form instead of the ion form has great potential, too. Sooner or later there is going to be a set of choices, and that will drive batteries, a major expense in many items, to lower prices enabling better power sources at lower cost.

Nanyang Technological University’s study showed how encasing algae protein in liquid droplets can dramatically enhance the algae’s light-harvesting and energy-conversion properties by up to three times.

The concept of a light-harvesting optofluidic microcavity to enhance biologically produced photoelectricity from light-harvesting proteins through whispering gallery modes. Artist’s Representation Image Credit: Nanyang Technological University. Click image for the largest view.

The variety of humble algae that cover the surface of ponds and seas could hold the key to boosting the efficiency of artificial photosynthesis, allowing scientists to produce more energy and lower waste in the process.

This energy is produced as the algae undergoes photosynthesis, which is the process used by plants, algae and certain bacteria to harness energy from sunlight and turn it into chemical energy. When light hits the droplet, light waves travel around the curved edges of the droplet. Light is effectively trapped within the droplet for a longer period of time, giving more opportunity for photosynthesis to take place, hence generating more energy.

By mimicking how plants convert sunlight into energy, artificial photosynthesis may be a sustainable way of generating electricity that does not rely on fossil fuels or natural gas, which are non-renewable. As the natural energy conversion rate from sunlight to electricity is low, boosting the overall electricity produced could make artificial photosynthesis commercially viable.

The study, led by Assistant Professor Chen Yu-Cheng from the School of Electrical and Electronic Engineering, looked at a particular type of protein found in red algae. These proteins, called phycobiliproteins, are responsible for absorbing light within algae cells to kick-start photosynthesis.

The Solar Clue

Phycobiliproteins harvest light energy from across the spectral range of light wavelengths, including those which chlorophylls absorb poorly, and convert it to electricity.

Assistant Prof Chen said, “Due to their unique light-emitting and photosynthetic properties, phycobiliproteins have promising potential applications in biotechnology and solid-state devices. Boosting the energy from the light-harvesting apparatus has been at the center of development efforts for organic devices that use light as a power source.”

The team’s research may lead towards a new, sustainable way of generating electricity from sunlight that does not rely on fossil fuels or natural gas, which are non-renewable. New bio-inspired technology based on phycobiliproteins could be used to make more efficient solar cells and paves the way for greater efficiency within artificial photosynthesis.

Using algae as a source of biological energy is a popular topic of interest in sustainability and renewable energy, as algae usage potentially reduces the amount of toxic by-products created in the manufacturing of solar panels.

The findings have been published and selected as the cover of scientific journal ACS Applied Materials Interfaces.

Details

Microalgae absorb sunlight and convert it into energy. In order to amplify the amount of energy that algae can generate, the research team developed a method to encase red algae within small liquid crystal micro-droplets that are 20 to 40 microns in size and exposed them to light.

When light hits the droplet, an effect known as the “whispering-gallery mode” occurs, in which light waves travel around the curved edges of the droplet. Light is effectively trapped within the droplet for a longer period of time, providing more opportunities for photosynthesis to take place and hence generating more energy.

The energy generated during photosynthesis in the form of free electrons can then be captured through electrodes as an electrical current.

Assistant Prof Chen explained, “The droplet behaves like a resonator that confines a lot of light. This gives the algae more exposure to light, increasing the rate of photosynthesis. A similar result can be obtained by coating the outside of the droplet with the algae protein too. By exploiting microdroplets as a carrier for light-harvesting biomaterials, the strong local electric field enhancement and photon confinement inside the droplet resulted in significantly higher electricity generation.”

The droplets can be easily produced in bulk at low cost, making the research team’s method widely applicable.

According to Chen, most algae-based solar cells produce an electrical power of 20-30 microwatts per square centimeter (µW/cm2). The NTU algae-droplet combination boosted this level of energy generation by at least two to three times, compared to the energy generation rate of the algae protein alone.

Artificial photosynthesis aims to replicate the natural biological process by which plants convert sunlight into chemical energy. The goal is to establish a way of making energy renewable, reliable, and storable without impacting the environment in a negative way.

One of the challenges of artificial photosynthesis is generating energy as efficiently as other solar-powered energy sources, such as solar panels. On average, solar panels have an efficiency rating of 15 to 20 per cent while artificial photosynthesis is currently estimated to be 4.5 per cent efficient.

“Artificial photosynthesis is not as efficient as solar cells in generating electricity. However, it is more renewable and sustainable. Due to increasing interest in environmentally-friendly and renewable technologies, extracting energy from light-harvesting proteins in algae has attracted substantial interest in the field of bio-energy,” Chen explained.

Chen envisions one potential use case of “algae farms,” where densely-growing algae in bodies of water could eventually be combined with larger liquid crystal droplets to create floating power generators.

In closing Chen noted, “The micro-droplets used in our experiments has the potential to be scaled up to larger droplets which can then be applied to algae outside of a laboratory environment to create energy. While some might consider algae growth to be unsightly, they play a very important role in the environment. Our findings show that there is a way to convert what some might view as ‘bio-trash’ into bio-power.”

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Perhaps this technology leap will put algae back on the hot list of alternative energy and fuel research. A doubling, perhaps tripling of output per sunlit area is going to help a great deal.

This research definitely deserves a congratulations for an idea well followed through. There is quite a way to go for scaling up and also resolving best practices for the separating of the oil, carbohydrates and water of aged out algae before processing. But the algae field is progressing, and that is welcome news indeed!

Pacific Northwest National Laboratory researchers can make methane from captured CO2 and renewably sourced hydrogen. The method converts captured carbon dioxide (CO2) into methane, the primary component of natural gas. The process offers recycling CO2 back into natural gas and a good way to store renewable energy sourced hydrogen. It would mean a short planetary carbon and hydrogen cycles.

Methane is the primary component of natural gas. Making methane from waste CO2 as PNNL researchers detail in a new study, could reduce carbon emissions while supplying a fuel with many applications. Image Credit: PublicDomainPictures | Pixabay.com. Click image for the largest view.

By streamlining a longstanding process in which CO2 is converted to methane, the researchers’ new method reduces the materials needed to run the reaction, the energy needed to fuel it and, ultimately, the selling price of the gas.

A key chemical player known as EEMPA makes the process possible. EEMPA is a PNNL-developed solvent that snatches CO2 from power plant flue gas, binding the greenhouse gas so it can be converted into useful chemicals.

Earlier this year, PNNL researchers revealed that using EEMPA in power plants could slash the price of carbon capture to 19 percent lower than standard industry costs – the lowest documented price of carbon capture. Now, in a study published in the journal ChemSusChem, the team reveals a new incentive – in cheaper natural gas – to further drive down costs.

When compared to the conventional method of methane conversion, the new process requires an initial investment that costs 32 percent less. Operation and maintenance costs are 35 percent cheaper, bringing the selling price of synthetic natural gas down by 12 percent.

Different methods for converting CO2 into methane have long been known. However, most processes rely on high temperatures and are often too expensive for widespread commercial use.

In addition to geologic production, methane can be produced from renewable or recycled CO2 sources, and can be used as fuel itself or as an H2 energy carrier. Though it is a greenhouse gas and requires careful supply chain management, methane has many applications, ranging from household use to industrial processes, explained lead author and PNNL chemist Jotheeswari Kothandaraman.

“Right now a large fraction of the natural gas used in the U.S. has to be pumped out of the ground,” said Kothandaraman, “and demand is expected to increase over time, even under climate change mitigation pathways. The methane produced by this process – made using waste CO2 and renewably sourced hydrogen – could offer an alternative for utilities and consumers looking for natural gas with a renewable component and a lower carbon footprint.”

To explore the use of EEMPA in converting CO2 to methane, Kothandaraman and her fellow authors studied the reaction’s molecular underpinnings, then assessed the cost of running the process at scale in a 550-megawatt power plant.

Conventionally, plant operators can capture CO2 by using special solvents that douse flue gas before it’s emitted from plant chimneys. But these traditional solvents have relatively high water content, making methane conversion difficult.

Using EEMPA instead reduces the energy needed to fuel such a reaction. The savings stem partly from EEMPA’s ability to make CO2 dissolve more easily, which means less pressure is needed to run the conversion.

The authors’ assessment identified further cost savings, in that CO2 captured by EEMPA can be converted to methane on site. Traditionally, CO2 is stripped from water-rich solvents and sent off site to be converted or stored underground. Under the new method, captured CO2 can be mixed with renewable hydrogen and a catalyst in a simple chamber, then heated to half the pressure used in conventional methods to make methane.

The reaction is efficient, the authors said, converting over 90 percent of captured CO2 to methane, though the ultimate greenhouse gas footprint depends on what the methane is used to do. And EEMPA captures over 95 percent of CO2 emitted in flue gas. The new process gives off excess heat, too, providing steam for power generation.

The chemical process highlighted in the paper represents one path among many, said Kothandaraman, where captured CO2 can be used as a feedstock to produce other valuable chemicals.

“I’ll be glad when I can make this process work for methanol as efficiently as it does for methane now. That’s my long-term goal.” Methanol has many more applications than methane, said Kothandaraman, who has sought to uncover the catalytic reactions that could produce methanol from CO2 for roughly a decade. Creating plastics from captured CO2 is another route the team plans to explore.

“It’s important that we not only capture CO2, but find valuable ways to use it,” said Ron Kent, Advanced Technologies Development Manager at SoCalGas, “and this study offers a cost-effective pathway toward making something valuable out of waste CO2.”

The study, “Integrated Capture and Conversion of CO2 Using a Water-lean, Post-Combustion CO2 Capture Solvent,” was supported by SoCalGas and the Department of Energy’s Technology Commercialization Fund and Office of Science.

In addition to Kothandaraman, authors include PNNL scientists Johnny Saavedra Lopez, Yuan Jiang, Eric D. Walter, Sarah D. Burton, Robert A. Dagle and David J. Heldebrant, who holds a joint appointment at Washington State University.

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While this work is critical to ongoing human survival in today’s population, at the moment there are immense social and political barriers getting and are succeeding in some places at taking natural gas out of the energy mix. One might want to keep an eye on the UK as it blunders into an energy and fuel disaster. We may get to see how the revolution from fossil fuels driven by mass hysteria and political opportunism actually drive human suffering and death.

The climatism hysteria and political opportunism are having their way while we already know that nature has long since figured out that connecting hydrogen to carbon is the best process to store energy in fuels. We already have a hydrogen economy and almost no one bothers to look.

The basic understanding of how things work the best has been lost, but the best way is still there, ready for humanity to use. That knowledge makes clear just how important this team’s work is at making the best way even easier to use and competitive in the marketplace where ultimately, the choice will be made.

Yet, its incorrect to think this team is slowing or stopping human suffering and death. They have improved the tools and that is far far more important. Its up to the rest of us to choose and use until the best processes form the future.

Nanyang Technological University researchers have devised a new less energy intensive method to make a key compound in nitrogen fertilizer, and that may pave the way to a more sustainable agricultural practice as global food demand rises.

The method devised by NTU researchers produces a compound known as ‘urea’, which is a natural product found in the urine of mammals, and an essential compound for fertilizers that is mass-produced industrially to increase crop yields.

However, the current Haber-Bosch process used to make urea is energy-intensive, requiring temperatures of 500° Celsius and pressures of two hundred times sea-level atmospheric pressure. It creates significant CO2 emissions, by using approximately 2% of global energy annually.

Seeking a more sustainable and energy efficient method, the team found a way to greatly improve an existing alternative approach to urea production known as electrocatalysis – using electricity to drive chemical reactions in a solution.

Using the nanomaterial indium hydroxide as a catalyst, the researchers reacted nitrate and carbon dioxide and found that the process formed urea five times more efficiently than previously reported attempts using electrocatalysis, specifically by causing the chemical reaction to take place in a ‘highly selective’ manner.

Co-lead author of the study, Professor Alex Yan from the NTU School of Materials Science and Engineering (MSE) said, “Our method essentially manipulates the chemical reaction process to become ‘highly selective’. By picking a better catalyst, we helped the nitrate ions and carbon dioxide molecules to optimally position themselves to facilitate urea formation, while suppressing the creation of unnecessary by-products like hydrogen, leading to higher efficiency and better urea yields.”

The study findings have been published in the journal Nature Sustainability, and the alternative urea production method has been patented by NTU.

This new method to produce urea may inspire the future design of sustainable chemistry approaches and contribute to ‘greener’ agricultural practices to feed the world’s growing population, said the research team.

The study reflects the university’s commitment to address humanity’s grand challenges on sustainability as part of the NTU 2025 strategic plan, which seeks to accelerate the translation of research discoveries into innovations that mitigate our impact on the environment.

As a proof of concept, the scientists tested the efficiency of their devised method in the lab and found that the approach achieved a urea yield of 53.4%, which is competitive with the current Haber-Bosch industrial method, that was first demonstrated in 1910.

The Haber-Bosch, a two-step thermal process, is fossil fuel reliant and can only happen at specific high temperatures, and high-pressure conditions. First, nitrogen and hydrogen are combined to make ammonia. Carbon dioxide is then bonded with it to make urea. By comparison, the new NTU approach is more environmentally friendly and simpler. It uses nitrate – a compound with bonds that require less energy to break – carbon dioxide, and hydrogen to directly trigger urea formation under room temperature.

The new method is simple enough to be adopted at both large and small scales, noted the research team. The electrocatalytic device could be easily operated by farmers to generate their own urea for fertilizers. The method could also one day be powered entirely by renewable energy.

First author of the research, Dr Lyu Chade, Research Fellow from the NTU School of MSE said, “With advances in solar technology, we may potentially use sunlight to power the electrocatalysis process in future, which can further help lower global emissions.”

For the next steps, the research team is aiming to achieve even higher yield results and to refine the catalytic selectivity, by exploring catalysts that would trigger faster reactions. They also plan to find a way to power the process using solar energy and to create a prototype device to demonstrate scaled up urea production.

The international research team includes researchers from the University of Texas at Austin, University of Science and Technology of China and Harbin Institute of Technology, China.

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This is an excellent example of great results from looking into an established energy intensive process. The potential here might seem small at 2% of annual fuels use, but that come to almost 2 million barrels of oil per day – no small thing at all. The question that comes to mind is just where would all the nitrate that might be needed get produced and at what price.

Urea is a nitrogen fertilizer. Its essential for food, fuel and fiber production. No nitrogen fertilizer would be catastrophic to hundreds of millions if not billions of people. The work by this team at NTU is far more important than one might first think.


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