Making Hydrogen Production Cheaper using New Ultra-Thin nano-material for splitting water


newultrathinThis is a water drop falling into water. Credit: Sarp Saydam/UNSW

UNSW Sydney chemists have invented a new, cheap catalyst for splitting water with an electrical current to efficiently produce clean hydrogen fuel.

The technology is based on the creation of ultrathin slices of porous metal-organic complex coated onto a foam electrode, which the researchers have unexpectedly shown is highly conductive of electricity and active for .

“Splitting water usually requires two different catalysts, but our catalyst can drive both of the reactions required to separate water into its two constituents, oxygen and hydrogen,” says study leader Associate Professor Chuan Zhao.

“Our fabrication method is simple and universal, so we can adapt it to produce ultrathin nanosheet arrays of a variety of these materials, called .

“Compared to other water-splitting electro-catalysts reported to date, our is also among the most efficient,” he says.

The UNSW research by Zhao, Dr Sheng Chen and Dr Jingjing Duan is published in the journal Nature Communications.

Hydrogen is a very good carrier for renewable energy because it is abundant, generates zero emissions, and is much easier to store than other energy sources, like solar or wind energy.

But the cost of producing it by using electricity to split water is high, because the most efficient catalysts developed so far are often made with precious metals, like platinum, ruthenium and iridium.

The catalysts developed at UNSW are made of abundant, non-precious metals like nickel, iron and copper. They belong to a family of versatile porous materials called , which have a wide variety of other potential applications.

Until now, metal-organic frameworks were considered poor conductors and not very useful for electrochemical reactions. Conventionally, they are made in the form of bulk powders, with their catalytic sites deeply embedded inside the pores of the material, where it is difficult for the water to reach.

By creating nanometre-thick arrays of metal-organic frameworks, Zhao’s team was able to expose the pores and increase the surface area for electrical contact with the .

“With nanoengineering, we made a unique metal-organic structure that solves the big problems of conductivity, and access to active sites,” says Zhao.

“It is ground-breaking. We were able to demonstrate that metal-organic frameworks can be highly conductive, challenging the common concept of these materials as inert electro-catalysts.”

Metal-organic frameworks have potential for a large range of applications, including fuel storage, drug delivery, and carbon capture. The UNSW team’s demonstration that they can also be highly conductive introduces a host of new applications for this class of material beyond electro-catalysis.

Explore further: Researchers report new, more efficient catalyst for water splitting

More information: Jingjing Duan et al, Ultrathin metal-organic framework array for efficient electrocatalytic water splitting, Nature Communications (2017). DOI: 10.1038/ncomms15341

 

 

Penn State U. – New ‘Flow-Cell’ Battery Recharged with Carbon Dioxide – Capturing CO2 Emissions for an Untapped Source of Energy


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The pH-gradient flow cell has two channels: one containing an aqueous solution sparged with carbon dioxide (low pH) and the other containing an aqueous solution sparged with ambient air (high pH). The pH gradient causes ions to flow across …more

Researchers have developed a type of rechargeable battery called a flow cell that can be recharged with a water-based solution containing dissolved carbon dioxide (CO2) emitted from fossil fuel power plants. The device works by taking advantage of the CO2 concentration difference between CO2 emissions and ambient air, which can ultimately be used to generate electricity.

The new flow cell produces an average power density of 0.82 W/m2, which is almost 200 times higher than values obtained using previous similar methods. Although it is not yet clear whether the process could be economically viable on a large scale, the early results appear promising and could be further improved with future research.

The scientists, Taeyong Kim, Bruce E. Logan, and Christopher A. Gorski at The Pennsylvania State University, have published a paper on the new method of CO2-to-electricity conversion in a recent issue of Environmental Science & Technology Letters.

“This work offers an alternative, simpler means to capturing energy from CO2 emissions compared to existing technologies that require expensive catalyst materials and very high temperatures to convert CO2 into useful fuels,” said Gorski.

While the contrast of gray-white smoke against a blue sky illustrates the adverse environmental impact of burning , the large difference in CO2 concentration between the two gases is also what provides an untapped energy source for generating electricity.fossil-fuels-co2-to-green-images

In order to harness the potential energy in this concentration difference, the researchers first dissolved CO2 gas and in separate containers of an aqueous solution, in a process called sparging. At the end of this process, the CO2-sparged solution forms bicarbonate ions, which give it a lower pH of 7.7 compared to the air-sparged solution, which has a pH of 9.4.

After sparging, the researchers injected each solution into one of two channels in a flow cell, creating a pH gradient in the cell. The flow cell has electrodes on opposite sides of the two channels, along with a semi-porous membrane between the two channels that prevents instant mixing while still allowing ions to pass through. Due to the pH difference between the two solutions, various ions pass through the membrane, creating a voltage difference between the two electrodes and causing electrons to flow along a wire connecting the electrodes.

After the flow cell is discharged, it can be recharged again by switching the channels that the solutions flow through. By switching the solution that flows over each electrode, the charging mechanism is reversed so that the electrons flow in the opposite direction. Tests showed that the cell maintains its performance over 50 cycles of alternating solutions.

The results also showed that, the higher the pH difference between the two channels, the higher the average power density. Although the pH-gradient flow cell achieves a power density that is high compared to similar cells that convert waste CO2 to electricity, it is still much lower than the power densities of fuel cell systems that combine CO2 with other fuels, such as H2.

However, the new flow cell has certain advantages over these other devices, such as its use of inexpensive materials and room-temperature operation. These features make the flow cell attractive for practical applications at existing .

“A system containing numerous identical flow cells would be installed at power plants that combust fossil fuels,” Gorski said. “The flue gas emitted from fossil fuel combustion would need to be pre-cooled, then bubbled through a reservoir of water that can be pumped through the flow cells.”

In the future, the researchers plan to further improve the flow cell performance.

“We are currently looking to see how the solution conditions can be optimized to maximize the amount of energy produced,” Gorski said. “We are also investigating if we can dissolve chemicals in the water that exhibit pH-dependent redox properties, thus allowing us to increase the amount of energy that can be recovered. The latter approach would be analogous to a flow battery, which reduces and oxidizes dissolved chemicals in aqueous solutions, except we are causing them to be reduced and oxidized here by changing the solution pH with CO2.”

Explore further: Chemists present an innovative redox-flow battery based on organic polymers and water

More information: Taeyoung Kim et al. “A pH-Gradient Flow Cell for Converting Waste CO2 into Electricity.” Environmental Science & Technology Letters. DOI: 10.1021/acs.estlett.6b00467

 

Rice University: Graphene Quantum Dots take on a NEW ‘green’ recycling role


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Graphene quantum dots may offer a simple way to recycle waste carbon dioxide into valuable fuel rather than release it into the atmosphere or bury it underground, according to Rice University scientists.

Nitrogen-doped (NGQDs) are an efficient electrocatalyst to make complex hydrocarbons from carbon dioxide, according to the research team led by Rice materials scientist Pulickel Ajayan. Using electrocatalysis, his lab has demonstrated the conversion of the greenhouse gas into small batches of ethylene and ethanol.

The research is detailed this week in Nature Communications.

Though they don’t entirely understand the mechanism, the researchers found NGQDs worked nearly as efficiently as copper, which is also being tested as a catalyst to reduce carbon dioxide into liquid fuels and chemicals. And NGQDs keep their catalytic activity for a long time, they reported.

“It is surprising because people have tried all different kinds of catalysts. And there are only a few real choices such as copper,” Ajayan said. “I think what we found is fundamentally interesting, because it provides an efficient pathway to screen new types of catalysts to convert carbon dioxide to higher-value products.”

Those problems are hardly a secret. Atmospheric carbon dioxide rose above 400 parts per million earlier this year, the highest it’s been in at least 800,000 years, as measured through ice-core analysis.

Carbon dots dash toward 'green' recycling role
Nitrogen-doped graphene quantum dots stand out from a substrate in a transmission electron microscope image. The dots are effective electrocatalysts that can reduce carbon dioxide, a greenhouse gas, to valuable hydrocarbons like ethylene …more

 

“If we can convert a sizable fraction of the carbon dioxide that is emitted, we could curb the rising levels of levels, which have been linked to climate change,” said co-author Paul Kenis of the University of Illinois.

In lab tests, NGQDs proved able to reduce carbon dioxide by up to 90 percent and convert 45 percent into either ethylene or alcohol, comparable to copper electrocatalysts.

Graphene quantum dots are atom-thick sheets of carbon atoms that have been split into particles about a nanometer thick and just a few nanometers wide. The addition of nitrogen atoms to the dots enables varying chemical reactions when an electric current is applied and a feedstock like carbon dioxide is introduced.

“Carbon is typically not a catalyst,” Ajayan said. “One of our questions is why this doping is so effective. When nitrogen is inserted into the hexagonal graphitic lattice, there are multiple positions it can take. Each of these positions, depending on where nitrogen sits, should have different . So it’s been a puzzle, and though people have written a lot of papers in the last five to 10 years on doped and defective carbon being catalytic, the puzzle is not really solved.”

Carbon dots dash toward 'green' recycling role
An illustration of a nitrogen-doped graphene quantum dot like those being tested at Rice University for use as catalysts to reduce carbon dioxide, a greenhouse gas, into valuable hydrocarbons. Credit: Ajayan Group/Rice University

 

“Our findings suggest that the pyridinic nitrogen (a basic organic compound) sitting at the edge of graphene leads the catalytic conversion of to hydrocarbons,” said Rice postdoctoral researcher Jingjie Wu, co-lead author of the paper. “The next task is further increasing nitrogen concentration to help increase the yield of hydrocarbons.” (Article continued below)

rice QD finetuneWhat is … A Quantum Dot

A quantum dot is a semiconductor whose excitons are confined in all three spatial dimensions. As a result, they have properties that are between those of bulk semiconductors and those of discrete molecules. They were discovered by Louis E. Brus, who was then at Bell Labs. The term “Quantum Dot” was coined by Mark Reed.

Researchers have studied quantum dots in transistors, solar cells, LEDs, and diode lasers. They have also investigated quantum dots as agents for medical imaging and hope to use them as qubits.

 

(Article Continued) Ajayan noted that while electrocatalysis is effective at lab scales for now, industry relies on scalable thermal catalysis to produce fuels and chemicals. “For that reason, companies probably won’t use it any time soon for large-scale production. But electrocatalysis can be easily done in the lab, and we showed it will be useful in the development of new catalysts.”

Explore further: Catalyst could make production of key chemical more eco-friendly

More information: Jingjie Wu et al, A metal-free electrocatalyst for carbon dioxide reduction to multi-carbon hydrocarbons and oxygenates, Nature Communications (2016). DOI: 10.1038/ncomms13869

 

Rice University: Carbon-Capture from Asphalt Based Nano-Materials: 154% of its Weight in CO2


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A Rice University laboratory has improved its method to turn plain asphalt into a porous material that can capture greenhouse gases from natural gas. In research detailed this month in Advanced Energy Materials (“Ultra-High Surface Area Activated Porous Asphalt for CO2 Capture through Competitive Adsorption at High Pressures”), Rice researchers showed that a new form of the material can sequester 154 percent of its weight in carbon dioxide at high pressures that are common at gas wellheads.

Raw natural gas typically contains between 2 and 10 percent carbon dioxide and other impurities, which must be removed before the gas can be sold. The cleanup process is complicated and expensive and most often involves flowing the gas through fluids called amines that can soak up and remove about 15 percent of their own weight in carbon dioxide. The amine process also requires a great deal of energy to recycle the fluids for further use.

“It’s a big energy sink,” said Rice chemist James Tour, whose lab developed a technique last year to turn asphalt into a tough, sponge-like substance that could be used in place of amines to remove carbon dioxide from natural gas as it was pumped from ocean wellheads.

rice-tour-asphalt-0916-id44535

 

Rice University scientists have improved their asphalt-derived porous carbon’s ability to capture carbon dioxide, a greenhouse gas, from natural gas. The capture material derived from untreated Gilsonite asphalt has a surface area of 4,200 square meters per gram. (Image: Almaz Jalilov/Rice University) 

 

Initial field tests in 2015 found that pressure at the wellhead made it possible for that asphalt material to adsorb, or soak up, 114 percent of its weight in carbon at ambient temperatures.

Tour said the new, improved asphalt sorbent is made in two steps from a less expensive form of asphalt, which makes it more practical for industry.

“This shows we can take the least expensive form of asphalt and make it into this very high surface area material to capture carbon dioxide,” Tour said. “Before, we could only use a very expensive form of asphalt that was not readily available.”

 

 micropores in carbon capture material
A scanning electron microscope image shows micropores in carbon capture material derived from common asphalt. The material created at Rice University sequesters 154 percent of its weight in carbon dioxide at 54 bar pressure, a common pressure at wellheads. (Image: Tour Group/Rice University)

 

 

The lab heated a common type asphalt known as Gilsonite at ambient pressure to eliminate unneeded organic molecules, and then heated it again in the presence of potassium hydroxide for about 20 minutes to synthesize oxygen-enhanced porous carbon with a surface area of 4,200 square meters per gram, much higher than that of the previous material.

The Rice lab’s initial asphalt-based porous carbon collected carbon dioxide from gas streams under pressure at the wellhead and released it when the pressure was released. The carbon dioxide could then be repurposed or pumped back underground while the porous carbon could be reused immediately.
In the latest tests with its new material, Tours group showed its new sorbent could remove carbon dioxide at 54 bar pressure. One bar is roughly equal to atmospheric pressure at sea level, and the 54 bar measure in the latest experiments is characteristic of the pressure levels typically found at natural gas wellheads, Tour said.
Source: Rice University

 

New Carbon Capture Hybrid-Membrane Boasts Greenhouse Gas Reductions


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Hybrid materials developed at Berkeley Lab could lead to cheaper ways to reduce power plant greenhouse gas emissions

In this animation, exhaust from a power plant contacts a hybrid membrane recently developed at Berkeley Lab. The membrane’s carbon dioxide highways (yellow) enable the rapid flow of carbon dioxide (red and white molecules) while maintaining selectivity over nitrogen (blue molecules). The membrane is eight times more carbon dioxide permeable than a polymer-only membrane. (Credit: Berkeley Lab)

A new, highly permeable carbon capture membrane developed by scientists from the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) could lead to more efficient ways of separating carbon dioxide from power plant exhaust, preventing the greenhouse gas from entering the atmosphere and contributing to climate change.

The researchers focused on a hybrid membrane that is part polymer and part metal-organic framework, which is a porous three-dimensional crystal with a large internal surface area that can absorb enormous quantities of molecules.

In a first, the scientists engineered the membrane so that carbon dioxide molecules can travel through it via two distinct channels. Molecules can travel through the polymer component of the membrane, like they do in conventional gas-separation membranes. Or molecules can flow through “carbon dioxide highways” created by adjacent metal-organic frameworks.

Initial tests show this two-route approach makes the hybrid membrane eight times more carbon dioxide permeable than membranes composed only of the polymer. Boosting carbon dioxide permeability is a big goal in efforts to develop carbon capture materials that are energy efficient and cost competitive.

The research is the cover article of the March issue of the journal Energy & Environmental Science.

“In our membrane, some CO2 molecules get an express ride through the highways formed by metal-organic frameworks, while others take the polymer pathway. This new approach will enable the design of higher performing gas separation membranes,” says Norman Su, a graduate student in the Chemical and Biomolecular Engineering Department at UC Berkeley and a user at the Molecular Foundry.

He conducted the research with Jeff Urban, Facility Director of the Inorganic Nanostructures Facility at the Molecular Foundry, and a team of scientists that included staff at the Advanced Light Source.

Capturing carbon emissions from electric power plants and other sources is a hot research topic because there’s a lot of room for improvement. The conventional way of separating carbon dioxide from flue gas is amine adsorption, which isn’t economical at scale because it adds significant capital cost and reduces the electrical output of power plants.

Scientists are exploring polymer membranes as a more energy efficient alternative to amine adsorption. These membranes are relatively inexpensive and easy to work with, but current commercial membranes have low carbon dioxide permeability. To overcome this, scientists have developed hybrid membranes that are part polymer and part metal-organic framework. These hybrids harness the carbon dioxide selectivity of metal-organic frameworks while maintaining the processability of polymers.

But, until now, scientists have not been able to engineer hybrid membranes with enough metal-organic frameworks to form continuous channels through the membrane. This means that, somewhere in a carbon dioxide molecule’s journey through the membrane, the molecule must contact the polymer. This constrains the molecule’s transport to the polymer.

In this latest research, Berkeley Lab scientists have developed a hybrid membrane in which metal-organic frameworks account for 50 percent of its weight, which is about 20 percent more than other hybrid membranes. Previously, the mechanical stability of a hybrid membrane limited the amount of metal-organic frameworks that could be packed in it.

“But we got our membrane to 50 weight percent without compromising its structural integrity,” says Su.

And 50 weight percent appears to be the magic number. At that threshold, there are so many metal organic frameworks in the membrane that they form a continuous network of highways through the membrane. When that happens, the hybrid membrane switches from having a single channel to transport carbon dioxide, in which the molecules must go through the polymer, to two channels, in which the molecules can either move through the polymer or through the metal-organic framework highways.

“This is the first hybrid polymer-MOF membrane to have these dual transport pathways, and it could be a big step toward more competitive carbon capture processes,” says Su.

In addition to fabricating the hybrid membrane at the Molecular Foundry, the scientists analyzed the material at beamline 12.2.2 of the Advanced Light Source.

The research was supported by the Department of Energy’s Office of Science, Berkeley Lab’s Laboratory-Directed Research and Development Program, and the Department of Defense.

The Advanced Light Source and the Molecular Foundry are DOE Office of Science User Facilities located at Berkeley Lab.

###

Lawrence Berkeley National Laboratory addresses the world’s most urgent scientific challenges by advancing sustainable energy, protecting human health, creating new materials, and revealing the origin and fate of the universe. Founded in 1931, Berkeley Lab’s scientific expertise has been recognized with 13 Nobel prizes. The University of California manages Berkeley Lab for the U.S. Department of Energy’s Office of Science. For more, visit www.lbl.gov.

DOE’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov

Updated:

2 for 1: Turning Smokestack Emissions into Carbon Nanotube-Based Batteries = Clean Emissions + Clean Renewable Energy: Vanderbilt & George Washington Universities


Smokestack Emissions Nano Carbon Capture id42759

“Our climate change solution is two fold: To transform the greenhouse gas carbon dioxide into valuable products and to provide greenhouse gas emission-free alternatives to today’s industrial and transportation fossil fuel processes,” Stuart Licht, professor of chemistry at George Washington University

An interdisciplinary team of scientists has worked out a way to make electric vehicles that are not only carbon neutral, but carbon negative, capable of actually reducing the amount of atmospheric carbon dioxide as they operate. They have done so by demonstrating how the graphite electrodes used in the lithium-ion batteries that power electric automobiles can be replaced with carbon material recovered from the atmosphere. The recipe for converting carbon dioxide gas into batteries is described in a paper published in the March 2 issue of the journal ACS Central Science (“Carbon Nanotubes Produced from Ambient Carbon Dioxide for Environmentally Sustainable Lithium-Ion and Sodium-Ion Battery Anodes”).

Converting Carbon Dioxide into BatteriesThe Solar Thermal Electrochemical Process (STEP) converts atmospheric carbon dioxide into carbon nanotubes that can be used in advanced batteries. (Image: Julie Turner, Vanderbilt University)

“Our climate change solution is two fold: To transform the greenhouse gas carbon dioxide into valuable products and to provide greenhouse gas emission-free alternatives to today’s industrial and transportation fossil fuel processes,” Stuart Licht, professor of chemistry at George Washington University said.

“In addition to better batteries other applications for the carbon nanotubes include carbon composites for strong, lightweight construction materials, sports equipment and car, truck and airplane bodies.” The unusual pairing of carbon dioxide conversion and advanced battery technology is the result of a collaboration between Dr. Licht, and the laboratory of assistant professor of mechanical engineering Cary Pint at Vanderbilt University. Licht adapted the lab’s solar thermal electrochemical process (STEP) so that it produces carbon nanotubes from carbon dioxide and with Pint by incorporating them into both lithium-ion batteries like those used in electric vehicles and electronic devices and low-cost sodium-ion batteries under development for large-scale applications, such as the electric grid. In lithium-ion batteries, the nanotubes replace the carbon anode used in commercial batteries.

The team demonstrated that the carbon nanotubes gave a small boost to the performance, which was amplified when the battery was charged quickly. In sodium-ion batteries, the researchers found that small defects in the carbon, which can be tuned by STEP, can unlock stable storage performance over 3.5 times above that of sodium-ion batteries with graphite electrodes. Most importantly, both carbon-nanotube batteries were exposed to about 2.5 months of continuous charging and discharging and showed no sign of fatigue.

Published on Feb 25, 2016: Video interview with Cary Pint explaining this research.

Scientists from Vanderbilt and George Washington universities have worked out a way to make electric vehicles not just carbon neutral but carbon negative by demonstrating how the graphite electrodes used in the lithium-ion batteries can be replaced with carbon recovered from the atmosphere.

“This trailblazing research has achieved yet another amazing milestone with the incorporation of the carbon nanotubes produced by Stuart Licht’s STEP reduction of carbon dioxide process into batteries for electric vehicles and large scale storage,” said Michael King, chair of GW’s Department of Chemistry. “We are thrilled by this translation of basic research into potentially useful consumer products while mitigating atmospheric carbon dioxide buildup. This is a win-win for everyone!”
The researchers estimate that with a battery cost of $325 per kWh (the average cost of lithium-ion batteries reported by the Department of Energy in 2013), a kilogram of carbon dioxide has a value of about $18 as a battery material – six times more than when it is converted to methanol – a number that only increases when moving from large batteries used in electric vehicles to the smaller batteries used in electronics.

And unlike methanol, combining batteries with solar cells provides renewable power with zero greenhouse emissions, which is needed to put an end to the current carbon cycle that threatens future global sustainability.

 

Licht also proposes a modified flue system for combustion plants that incorporates this process could be self-sustaining, as exemplified by a new natural gas power plant with zero carbon dioxide emissions. That’s because the side product of the process is pure oxygen, which plants could then use for further combustion. The calculated total cost per metric tonne of CNTs would be much less expensive than current synthetic methods.

 

“This approach not only produces better batteries but it also establishes a value for carbon dioxide recovered from the atmosphere that is associated with the end-user battery cost unlike most efforts to reuse CO2 that are aimed at low-valued fuels, like methanol, that cannot justify the cost required to produce them,” said Pint.
Source: Vanderbilt University

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Berkeley National Laboratory: Weaving a new story for Nanomaterials (COFS and MOFs)


Nano Weaving RD_COF

There are many different ways to make nano-materials but weaving, the oldest and most enduring method of making fabrics, has not been one of them – until now. An international collaboration led by scientists at the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California (UC) Berkeley, has woven the first three-dimensional covalent organic frameworks (COFs) from helical organic threads. The woven COFs display significant advantages in structural flexibility, resiliency and reversibility over previous COFs – materials that are highly prized for their potential to capture and store carbon dioxide then convert it into valuable chemical products.

“We have taken the art of weaving into the atomic and molecular level, giving us a powerful new way of manipulating matter with incredible precision in order to achieve unique and valuable mechanical properties,” says Omar Yaghi, a chemist who holds joint appointments with Berkeley Lab’s Materials Sciences Division and UC Berkeley’s Chemistry Department, and is the co-director of the Kavli Energy NanoScience Institute (Kavli-ENSI).

“Weaving in chemistry has been long sought after and is unknown in biology,” Yaghi says. “However, we have found a way of weaving organic threads that enables us to design and make complex two- and three-dimensional organic extended structures.”

Yaghi is the corresponding author of a paper in Science reporting this new technique. The paper is titled “Weaving of organic threads into a crystalline covalent organic framework.” The lead authors are Yuzhong Liu, Yanhang Ma and Yingbo Zhao. Other co-authors are Xixi Sun, Felipe Gándara, Hiroyasu Furukawa, Zheng Liu, Hanyu Zhu, Chenhui Zhu, Kazutomo Suenaga, Peter Oleynikov, Ahmad Alshammari, Xiang Zhang and Osamu Terasaki.

COFs and their cousin materials, metal organic frameworks (MOFs), are porous three-dimensional crystals with extraordinarily large internal surface areas that can absorb and store enormous quantities of targeted molecules. Invented by Yaghi, COFs and MOFs consist of molecules (organics for COFs and metal-organics for MOFs) that are stitched into large and extended netlike frameworks whose structures are held together by strong chemical bonds. Such frameworks show great promise for, among other applications, carbon sequestration.

Through another technique developed by Yaghi, called “reticular chemistry,” these frameworks can also be embedded with catalysts to carry out desired functions: for example, reducing carbon dioxide into carbon monoxide, which serves as a primary building block for a wide range of chemical products including fuels, pharmaceuticals and plastics.

In this latest study, Yaghi and his collaborators used a copper(I) complex as a template for bringing threads of the organic compound “phenanthroline” into a woven pattern to produce an immine-based framework they dubbed COF-505. Through X-ray and electron diffraction characterizations, the researchers discovered that the copper(I) ions can be reversibly removed or restored to COF-505 without changing its woven structure. Demetalation of the COF resulted in a tenfold increase in its elasticity and remetalation restored the COF to its original stiffness.

“That our system can switch between two states of elasticity reversibly by a simple operation, the first such demonstration in an extended chemical structure, means that cycling between these states can be done repeatedly without degrading or altering the structure,” Yaghi says. “Based on these results, it is easy to imagine the creation of molecular cloths that combine unusual resiliency, strength, flexibility and chemical variability in one material.”

Yaghi says that MOFs can also be woven as can all structures based on netlike frameworks. In addition, these woven structures can also be made as nanoparticles or polymers, which means they can be fabricated into thin films and electronic devices.

“Our weaving technique allows long threads of covalently linked molecules to cross at regular intervals,” Yaghi says. “These crossings serve as points of registry, so that the threads have many degrees of freedom to move away from and back to such points without collapsing the overall structure, a boon to making materials with exceptional mechanical properties and dynamics.”

Source: Lawrence Berkeley National Laboratory

KAUST: A greener approach to a green solution


KAUST Carbon Capture untitled

An environment-friendly method for synthesizing a microporous material that can adsorb carbon dioxide emitted from fossil fuel-driven power plants has been developed by researchers at KAUST1.

Burning carbon-based energy sources to meet the world’s energy demands is recognized to have a negative impact on our planet: global warming and ocean acidification could leave an indelible mark on Earth. The slow development process and low efficiency of alternatives such as nuclear fusion and solar power makes it difficult to wean ourselves off the use of conventional fossil fuels.

An alternative strategy is to develop technologies that mitigate the deleterious effects of fossil fuels. Carbon capture is one such approach, and proposes to use porous materials that can adsorb and store emitted carbon dioxide at the end of the energy generation process to prevent it from entering the atmosphere.

Metal–organic frameworks (MOFs) are one promising class of porous solid-state materials. These crystalline networks are made up of metal ions or clusters interconnected by organic molecules.

“The periodic arrangement of these organic and inorganic molecular building blocks gives MOFs one of their most defining properties: a functional and tunable pore system,” said KAUST Professor of Chemical Science Mohamed Eddaoudi. “The deliberate control of the available and accessible space shape, size and functionality enables adsorbing and storing select gases.”

The translation of a prospective MOF that selectively captures carbon dioxide from a laboratory scale to industrial scale settings requires the development of economical synthetic approaches. The manufacturing process frequently involves organic solvents that can also have a negative impact on the environment.

Eddaoudi and colleagues from KAUST’s Advanced Membranes & Porous Materials Research Center have developed a simple and solvent-free method to create a MOF adsorbent that selectively captures carbon dioxide.

The reported MOF structure, which they call SIFSIX-3-Ni, was made by dry mechanical mixing the organic component pyrazine with the inorganic solid NiSiF6 at a molar ratio of four to one, and then wetting with a few drops of water. This was heated for four hours at 65 degrees Celsius and then at 105 degrees Celsius for an additional four hours.

The team confirmed the efficient adsorption of carbon dioxide, even in an environment with very low carbon dioxide content. The authors also proved that the material is tolerant to the acidic gas hydrogen sulfide that is present in natural gas.

Reference

  1.  Shekhah, O., Belmabkhout, Y., Adil, K., Bhatt, P. M., Cairns, A. J. & Eddaoudi, M. A facile solvent-free synthesis route for the assembly of a highly CO2 selective and H2S tolerant NiSIFSIX metal–organic framework. Chemical Communications 51, 13595-13598 (2015). | article

Smart Grid and Nanotechnologies: How can Nanotechnology Reduce CO2 emissions? A Solution For Clean and Sustainable Energy


Renewable Energy Pix

Environmental sustainability remains a big trend; topics such as climate change and global warming are generating a lot of discussion. Growing world energy demand from fossil fuels plays a key role in the upward trend in CO2 emissions and is the main source of human-induced climate changes. While energy systems around the world remain at vastly different stages of development, all countries share a common problem: they are far away from achieving sustainable energy systems. As levels of CO2 and other greenhouse gases continue to rise in the atmosphere, with historical maximums reached lately, sustainability in energy generation and energy efficiency principles is becoming ever more important.

Introduction

For the first time in recorded history, more people worldwide are living in urban areas than in rural. The urbanization trend picked up pace in the 20th century and has accelerated since. Urbanization manifests itself in two ways: expansion of existing cities and creation of new ones.1 Cities are already the source of close to 80% of global CO2 (carbon-dioxide) emissions and will account for an ever-higher percentage in the coming years.

Too much CO2 in the atmosphere has been linked to climate change. If humanity continued with the same solutions that have been used to address urban development needs in the past, the resulting urban ecological footprint will not be sustainable: we would need the equivalent of two planets to maintain our lifestyles by the 2030s. The challenge is to meet the demands of urbanization in an economically viable, socially inclusive, and environmentally sustainable fashion.1,2

According to a World Energy Council study,3 global demand for primary energy is expected to increase by between 27% and 61% by 2050. Climate change is expected to lead to changes in a range of climatic variables, most notably temperature levels. Since electricity demand is closely influenced by temperature, there is likely to be an impact on power demand patterns. The magnitude of the potential impact of future climate changes on electricity demand will depend on patterns in the power use, as well as long-term socio-economic trends.

The latest assessment by Working Group I of the Intergovernmental Panel on Climate Change, released in September 2013, concluded that climate change remains one of the greatest challenges facing society. Warming of the climate system is unequivocal, human-influenced, and many unprecedented changes have been observed throughout the climate system since 1950. Limiting climate change will require substantial and sustained reductions of greenhouse gas emissions.4

Consumption patterns, together with aging and urbanization in some countries seem to have bigger implications for health and the reduction of carbon emissions than the total number of people in the world.5 As developing and newly industrialized countries improve their standards of living, their use of air conditioning and other weather-dependent consumption will likely increase their sensitivity to climate change.6 On the other hand, reducing consumption and achieving more sustainable lifestyles in rich countries will likely represent the most effective way to reduce carbon emissions.

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How can nanotechnology reduce CO2 emission?

“The Grid” and Improving Efficiencies

Nanotechnology is a platform whereby matter is manipulated at the atomic level. There are various ways that nanotechnology can be applied along the Smart Grid to help reduce CO2 emissions.

The major impact of nanotechnology on the energy sector is likely to improve the efficiency of current technologies to minimize use of fossil fuels. Any effort to reduce emissions in vehicles by reducing their weight and, in turn, decreasing fuel consumption can have an immediate and significant global impact.

It is estimated that a 10% reduction in weight of the vehicle corresponds to a 10% reduction in fuel consumption, leading to a proportionate fall in emissions. In recognition of the above, there is growing interest worldwide in exploring means of achieving weight reduction in automobiles through use of novel materials. For example, use of lighter, stronger, and stiffer nano-composite materials is considered to have the potential to significantly reduce vehicle weight.9,49

Nanotechnology is applied in aircraft coatings, which protect the materials from the special conditions of the environment where they are used (instead of the conventional bulk metals such as steel). Since the amount of CO2 emitted by an aircraft engine is directly related to the amount of fuel burned, CO2 can be reduced by making the airplane lighter.

Nanocoatings are one of the options for aerospace developers, but also for automotive, defense, marine, and plastics industries.49 Lufthansa Cargo uses the most advanced technologies and innovative processes including efficient jet engines, nanotechnology in aircraft coatings, new composites or regular jet engine cleaning – and of course monitoring overall aircraft weight. It is often a matter of only a few grams. However, given 15,000 to 16,000 flights a year and an average flight time of about 6 hours, the cumulative effect of a number of grams can quickly add up to tons. The removal of a 350 gram phone handset resulted in jet fuel savings of 3.5 tons in a year.50

Nanotechnology is already applied to improve fuel efficiency by incorporation of nanocatalysts. Enercat, a third generation nanocatalyst developed by Energenics, uses the oxygen storing cerium oxide nanoparticles to promote complete fuel combustion, which helps in reducing fuel consumption. Recently, the company has demonstrated fuel savings of 8%–10% on a mixed fleet of diesel vehicles in Italy.51

Reducing friction and improving wear resistance in engine and drive train components is of vital importance in the automotive sector. Based on the estimates made by a Swedish company Applied Nano Surfaces, reducing friction can lower the fuel consumption by about 2% and result in cutting down CO2 emissions by 500 million tons per year from trucks and other heavy vehicles in Sweden alone.9 Thanks to nanomaterials like silica, many tires will in the future be capable of attaining the best rating, the green category A. Cars equipped with category A tires consume approximately 7.5% less fuel than those with tires of the minimum standard (category G).52

Residential and commercial buildings contribute to 11% of total greenhouse gas emissions. Space heating and cooling of residential buildings account for 40% of the total residential energy use. Nanostructured materials, such as aerogels, have the potential to greatly reduce heat transfer through building elements and assist in reducing heating loads placed on air-conditioning/heating systems. Aerogel is a nanoporous super-insulating material with extremely low density; silica aerogel is the lightest solid material known with excellent thermal insulating properties, high temperature stability, very low dielectric constant and high surface area.51

Nanotechnology is positioned to create significant change across several domains, especially in energy where it may bring large and possibly sudden performance gains to renewable sources and Smart Grids. Nanotech enhancements may also increase battery power by orders of magnitude, allowing intermittent sources such as solar and wind to provide a larger share of overall electricity supply without sacrificing stability. Nanotech sensors will also enable Smart Grids and foster more flexible and decentralized electricity management.53

Nanotechnology may accelerate the technology behind renewables in various ways:

  • experts are discovering means to apply nanotechnology to photovoltaics, which would produce solar panels with double or triple the output by 2020;
  • wind turbines stand to be improved from high-performance nano-materials like graphene, a nano-engineered one-atom thick layer of mineral graphite that is 100 times stronger than steel. Nanotechnology will enable light and stiff wind blades that spin at lower wind speeds than regular blades;
  • nanotechnology could play a major role in the next generation of batteries. For example, coating the surface of an electrode with nanoparticles increases the surface area, thereby allowing more current to flow between the electrode and the chemicals inside the battery. Such techniques could increase the efficiency of electric and hybrid vehicles by significantly reducing the weight of the batteries. Moreover, superior batteries would complement renewables by storing energy economically, thus offsetting the whole issue of intermittent generation.

In a somewhat more distant future, we may see electricity systems apply nanotechnology in transmission lines. Research indicates that it is possible to develop electrical wires using carbon nanotubes that can carry higher loads and transmit without power losses even over hundreds of kilometers. The implications are significant, as it would increase the efficiency of generating power where the source is easiest to harness.53

Semiconductor devices, transistors, and sensors will benefit from nanotechnology especially in size and speed. Nanotech sensors could be used for the Smart Grid to detect issues ahead of time, ie, to measure degrading of underground cables or to bring down the price of chemical sensors already available for transformers. Nanotechnology will likely become indispensable for the Smart Grid to fully evolve in the near future.54

Energy efficiency is a way of managing and restraining the growth of energy consumption. It is one of the easiest and most cost effective ways to combat climate change, improve the competitiveness of businesses, and reduce energy costs for consumers.7

More on Using Nanotechnology to Reduce Carbon-Based Emissions

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Berkley Lab: A Better Way of Scrubbing CO2

Berkeley Lab Researchers Find Way to Improve the Cost-Effectiveness Through the Use of MOFs

A means by which the removal of carbon dioxide (CO2) from coal-fired power plants might one day be done far more efficiently and at far lower costs than today has been discovered by a team of researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab). By appending a diamine molecule to the sponge-like solid materials known as metal-organic-frameworks (MOFs), the researchers were able to more than triple the CO2-scrubbing capacity of the MOFs, while significantly reducing parasitic energy.

Read the Full Article Here: https://genesisnanotech.wordpress.com/2015/03/17/berkley-lab-a-better-way-of-scrubbing-co2/

Nanotechnology material could help reduce CO2 emissions from coal-fired power plants

1-KAUST Materials gilles-coinsliderUniversity of Adelaide researchers have  developed a new nanomaterial that could help reduce carbon dioxide emissions  from coal-fired power stations.

The new nanomaterial, described in the Journal of the  American Chemical Society (“Post-synthetic Structural Processing in a  Metal–Organic Framework Material as a Mechanism for Exceptional CO2/N2 Selectivity”), efficiently separates the  greenhouse gas carbon dioxide from nitrogen, the other significant component of  the waste gas released by coal-fired power stations. This would allow the carbon  dioxide to be separated before being stored, rather than released to the  atmosphere.
“A considerable amount of Australia‘s – and the world’s – carbon  dioxide emissions come from coal-fired power stations,” says Associate Professor  Christopher Sumby, project leader and ARC Future Fellow in the  University’s School of Chemistry and Physics.

Read the Full Article Here: https://genesisnanotech.wordpress.com/2013/07/10/nanotechnology-material-could-help-reduce-co2-emissions-from-coal-fired-power-plants/

One Nano-Crystal – Many Facets – Reducing Fuel Toxins

cubic CeO2 nanoparticlesWhen it comes to reducing the toxins released by burning gasoline, coal, or other such fuels, the catalyst needs to be reliable. Yet, a promising catalyst, cerium dioxide (CeO2), seemed erratic. The catalyst’s three different surfaces behaved differently. For the first time, researchers got an atomically resolved view of the three structures, including the placement of previously difficult-to-visualize oxygen atoms. This information may provide insights into why the surfaces have distinct catalytic properties (“Probing the Surface Sites of CeO2 Nanocrystals with Well-Defined Surface Planes via Methanol Adsorption and Desorption”).

Read the Full Article Here: https://genesisnanotech.wordpress.com/2015/06/12/one-nano-crystal-many-facets-reducing-fuel-toxins/

Conclusion

This review demonstrates the potential for reduction of CO2 emissions that Smart Grids can potentially achieve. Power grid modernization is an evolution that will continue for years or decades, and providing a robust foundation for new applications and technologies is imperative.

The electric power industry is facing tremendous opportunities and becoming increasingly important in the emerging low-carbon economy. Governments are still dominant players in high-cost smart-grid investments. This suggests the need for a policy framework that attracts private capital investment, especially from renewable project developers, and communication and ICT companies.

The challenge we face is neither a technical nor policy one – it is political: the current pace of action is simply insufficient. The technologies to reduce emission levels to a level consistent with the 2°C target are available and we know which policies we can use to deploy them. However, the political will to do so remains weak. This lack of political will comes with a price: we will have to undertake steeper and more costly actions to potentially bridge the emissions gap by 2020.4 However, technical possibilities aside, the key to reducing emission levels will be the tough but unavoidable decision that reducing carbon pollution must be of the highest priority.

To Read the Full Article Go Here: http://www.dovepress.com/smart-grid-and-nanotechnologies-a-solution-for-clean-and-sustainable-e-peer-reviewed-fulltext-article-EECT

Carbon Release from the Oceans Helped End the Ice Age


Carbon Ice Age -126760907_YaleNews

New techniques are allowing scientists to understand how carbon dioxide, released from the deep ocean, helped to end the last ice age and create our current climate.

An international team, including Yale paleoclimatologist Michael Henehan, studied the shells of ancient marine organisms that lived in surface waters of the southern Atlantic and eastern equatorial Pacific oceans thousands of years ago. The researchers determined that high concentrations of dissolved carbon dioxide in those waters coincided with rises in atmospheric carbon dioxide and global temperatures at the end of the last ice age.

The findings give scientists valuable insights into how the ocean can affect the carbon cycle and climate change, say the researchers.

A study describing the research appears in Nature. Joint lead authors of the study are Miguel Martínez-Botí of the Univ. of Southampton and Gianluca Marino of the Australian National Univ. The Univ. of Southampton led the effort.

“This is an exciting time for research into past climates,” said Henehan, who is a postdoctoral associate in the Dept. of Geology and Geophysics. “Advances in technologies and improvements in our methods have allowed us in this study to show just how critical carbon dioxide release from the oceans was in kicking the Earth out of the last ice age and into the climate state we have today.”

Henehan said Yale scientists are using the same technique to look even further back in time, investigating whether changes in atmospheric carbon dioxide played a role in the mass extinction of species at the end of the Cretaceous period.

Source: Yale Univ.