A UCLA study shows that capturing carbon dioxide and turning it into commercial products, such as fuels or construction materials, could become a new global industry.

From the study, linked below, with a full explanation and discussion. Image Credit: UCLA Samueli School of Engineering. Click image for the largest view.

UCLA, the University of Oxford and five other institutions’ research has been published in Nature. The paper is the most comprehensive study to date investigating the potential future scale and cost of 10 different ways to use carbon dioxide, including in fuels and chemicals, plastics, building materials, soil management and forestry. The study considered processes using carbon dioxide captured from waste gases that are produced by burning fossil fuels or from the atmosphere by an industrial process.

Going beyond a step the most previous research on the subject, the authors also considered processes that use carbon dioxide captured biologically by photosynthesis.

The research found that on average each utilization pathway could use around 0.5 gigatonnes of carbon dioxide per year that would otherwise escape into the atmosphere. (A tonne, or metric ton of about 2200 pounds, is equivalent to 1,000 kilograms, and a gigatonne is 1 billion tonnes, or about 1.1 billion U.S. tons.) The math of 0.5 gigatonnes works out to 550 million tons or 1,100,000,000,000 pounds.

A top-end scenario could see more than 10 gigatonnes of carbon dioxide a year used, at a theoretical cost of under $100 per tonne of carbon dioxide. The researchers noted, however, that the potential scales and costs of using carbon dioxide varied substantially across sectors.

Emily Carter, a distinguished professor of chemical and biomolecular engineering at the UCLA Samueli School of Engineering and a co-author of the paper said, “The analysis we presented makes clear that carbon dioxide utilization can be part of the solution to combat climate change, but only if those with the power to make decisions at every level of government and finance commit to changing policies and providing market incentives across multiple sectors. The urgency is huge and we have little time left to effect change.”

According to the Intergovernmental Panel on Climate Change, keeping global warming to 1.5 degrees Celsius over the rest of the 21st century will require the removal of carbon dioxide from the atmosphere on the order of 100 to 1,000 gigatonnes of carbon dioxide. Currently, fossil carbon dioxide emissions are increasing by over 1% annually, reaching a record high of 37 gigatonnes of carbon dioxide in 2018.

Cameron Hepburn, one of the study’s lead authors, director of Oxford’s Smith School of Enterprise and Environment said, “Greenhouse gas removal is essential to achieve net zero carbon emissions and stabilize the climate. We haven’t reduced our emissions fast enough, so now we also need to start pulling carbon dioxide out of the atmosphere. Governments and corporations are moving on this, but not quickly enough. The promise of carbon dioxide utilization is that it could act as an incentive for carbon dioxide removal and could reduce emissions by displacing fossil fuels.”

Critical to the success of these new technologies as mitigation strategies will be a careful analysis of their overall impact on the climate. Some are likely to be adopted quickly simply because of their attractive business models. For example, in certain kinds of plastic production, using carbon dioxide as a feedstock is a more profitable and environmentally cleaner production process than using conventional hydrocarbons, and it can displace up to three times as much carbon dioxide as it uses.

Biological uses might also present opportunities to reap co-benefits. In other areas, utilization could provide a “better choice” alternative during the global decarbonization process. One example might be the use of fuels derived from carbon dioxide, which could find a role in sectors that are harder to decarbonize, such as aviation.

The authors stressed that there is no “magic bullet” approach.

Carter, who also is UCLA’s executive vice chancellor and provost, and the Gerhard R. Andlinger Professor in Energy and Environment Emeritus at Princeton University said, “I would start by incentivizing the most obvious solutions – most of which already exist – that can act at the gigatonne scale in agriculture, forestry and construction. At the same time, I would aggressively invest in R&D across academia, industry and government labs – much more so than is being done in the U.S., especially compared to China – in higher-tech solutions to capture and convert carbon dioxide to useful products that can be developed alongside solutions that already exist in agriculture, forestry and construction.”

Your humble writer has always suggested that the human activity on the planet gets to a carbon cycle in sync with the environment. Its still a saddening moment to again see the reliance on climate change as the single motivator when a CO2 recycling economic element has such potential to enrich the whole of the planet’s ecosystem.

The study is very welcome indeed. Its a certainty that when the technology of CO2 recycling produces products at competitive pricing the producers and consumers will be there. One hopes the study motivates increased efforts to discover and develop the processes to get CO2 recycling underway.

Researchers at the Department of Energy’s SLAC National Accelerator Laboratory and Stanford University have shown for the first time that a cheap catalyst can split water and generate hydrogen gas for hours on end in the harsh environment of a commercial device.

A commercial electrolyzer used in the experiments. Electrodes sprayed with catalyst powder are stacked inside the central metal plates and compressed with bolts and washers. Water flows in through a tube on the right, and hydrogen and oxygen gases flow out through tubes at left. Image Credit: Nel Hydrogen. Click image for the largest view.

The electrolyzer technology, which is based on a polymer electrolyte membrane (PEM), has potential for large-scale hydrogen production powered by renewable energy, but it has been held back in part by the high cost of the precious metal catalysts, like platinum and iridium, needed to boost the efficiency of the chemical reactions.

The study points the way toward a cheaper solution as the researchers report in Nature Nanotechnology.

Thomas Jaramillo, director of the SUNCAT Center for Interface Science and Catalysis, who led the research team said, “Hydrogen gas is a massively important industrial chemical for making fuel and fertilizer, among other things. It’s also a clean, high-energy-content molecule that can be used in fuel cells or to store energy generated by variable power sources like solar and wind. But most of the hydrogen produced today is made with fossil fuels, adding to the level of CO2 in the atmosphere. We need a cost-effective way to produce it with clean energy.”

There’s been extensive work over the years to develop alternatives to precious metal catalysts for PEM systems. Many have been shown to work in a laboratory setting, but Jaramillo said that to his knowledge this is the first to demonstrate high performance in a commercial electrolyzer. The device was manufactured by a PEM electrolysis research site and factory in Connecticut for Nel Hydrogen, the world’s oldest and biggest manufacturer of electrolyzer equipment.

Electrolysis works much like a battery in reverse: Rather than generating electricity, it uses electrical current to split water into hydrogen and oxygen. The reactions that generate hydrogen and oxygen gas take place on different electrodes using different precious metal catalysts. In this case, the Nel Hydrogen team replaced the platinum catalyst on the hydrogen-generating side with a catalyst consisting of cobalt phosphide nanoparticles deposited on carbon to form a fine black powder, which was produced by the researchers at SLAC and Stanford. Like other catalysts, it brings other chemicals together and encourages them to react.

The cobalt phosphide catalyst operated extremely well for the entire duration of the test, more than 1,700 hours – an indication that it may be hardy enough for everyday use in reactions that can take place at elevated temperatures, pressures and current densities and in extremely acidic conditions over extended lengths of time, said McKenzie Hubert, a graduate student in Jaramillo’s group who led the experiments with Laurie King, a SUNCAT research engineer who has since joined the faculty of Manchester Metropolitan University.

Hubert added, “Our group has been studying this catalyst and related materials for a while, and we took it from a fundamental lab-scale, experimental stage through testing it under industrial operating conditions, where you need to cover a much larger surface area with the catalyst and it has to function under much more challenging conditions.”

One of the most important elements of the study was scaling up the production of the cobalt phosphide catalyst while keeping it very uniform – a process that involved synthesizing the starting material at the lab bench, grinding with a mortar and pestle, baking in a furnace and finally turning the fine black powder into an ink that could be sprayed onto sheets of porous carbon paper. The resulting large-format electrodes were loaded into the electrolyzer for the hydrogen production tests.

While the electrolyzer development was funded by the Defense Department, which is interested in the oxygen-generating side of electrolysis for use in submarines, Jaramillo said the work also aligns with the goals of DOE’s H2@Scale initiative, which brings DOE labs and industry together to advance the affordable production, transport, storage and use of hydrogen for a number of applications, and the fundamental catalyst research was funded by the DOE Office of Science.

Katherine Ayers, vice president for research and development at Nel and a co-author of the paper, said, “Working with Tom gave us an opportunity to see whether these catalysts could be stable for a long time and gave us a chance to see how their performance compared to that of platinum.”

“The performance of the cobalt phosphide catalyst needs to get a little bit better, and its synthesis would need to be scaled up,” she said. “But I was quite surprised at how stable these materials were. Even though their efficiency in generating hydrogen was lower than platinum’s, it was constant. A lot of things would degrade in that environment.”

While the platinum catalyst represents only about 8 percent of the total cost of manufacturing hydrogen with PEM, the fact that the market for the precious metal is so volatile, with prices swinging up and down, could hold back development of the technology, Ayers explained. Reducing and stabilizing that cost will become increasingly important as other aspects of PEM electrolysis are improved to meet the increasing demand for hydrogen in fuel cells and other applications.

Well now, it looks like this technology just might make it to commercial scale. The hydrogen economy folks must be thrilled after enduring so many high hope – but not practical ideas. Lets hope this technology is the breakthrough we’ve been waiting for.

University of Waterloo scientists have created an ‘artificial leaf’ by inexpensively recycling and converting harmful carbon dioxide (CO2) into a useful alternative fuel.

The new technology, outlined in a paper published in the journal Nature Energy, was inspired by the way plants use energy from sunlight to turn carbon dioxide into food.

Yimin Wu, an engineering professor at the University of Waterloo who led the research said, “We call it an artificial leaf because it mimics real leaves and the process of photosynthesis. A leaf produces glucose and oxygen. We produce methanol and oxygen.”

Making methanol from carbon dioxide, the alleged primary contributor to global warming, would both reduce greenhouse gas emissions and provide a substitute for the fossil fuels that create them.

The key to the process is a cheap, optimized red powder called cuprous oxide.

An hour-long chemical reaction creates the engineered red powder that is the key to new technology to turn carbon dioxide into fuel. Image Credit: University of Waterloo . Click image for the largest view,

Engineered to have as many eight-sided particles as possible, the powder is created by a chemical reaction when four substances – glucose, copper acetate, sodium hydroxide and sodium dodecyl sulfate – are added to water that has been heated to a particular temperature.

The powder then serves as the catalyst, or trigger, for another chemical reaction when it is mixed with water into which carbon dioxide is blown and a beam of white light is directed with a solar simulator.

“This is the chemical reaction that we discovered,” said Wu, who has worked on the project since 2015. “Nobody has done this before.”

The reaction produces oxygen, as in photosynthesis, while also converting carbon dioxide in the water-powder solution into methanol. The methanol is collected as it evaporates when the solution is heated.

Next steps in the research include increasing the methanol yield and commercializing the patented process to convert carbon dioxide collected from major greenhouse gas sources such as power plants, vehicles and oil drilling.

“I’m extremely excited about the potential of this discovery to change the game,” said Wu, a professor of mechanical and mechatronics engineering, and a member of the Waterloo Institute for Nanotechnology. “Climate change is an urgent problem and we can help reduce CO2 emissions while also creating an alternative fuel.”

Wu collaborated on the paper, Facet-dependent active sites of a single Cu2O particle photocatalyst for CO2 reduction to methanol, with Tijana Rajh and other researchers at the Argonne National Laboratory in Illinois, as well as scientists at California State University, Northridge, and the City University of Hong Kong.

Another looks good, sounds good idea, that functions. We’re missing the operating parameters like, must the CO2 be a pure flow, from the atmosphere, or will an effluent gas flow do? Then there are the costs to build them and a unit’s lifespan. Perhaps there is a market for this idea, but there is a long way to go to get to scale to produce fuel in volume at a price folks will pay.  The best news is it makes a liquid fuel that stores without being under pressure.

Pacific Northwest National Laboratory scientists have uncovered a root cause of the growth of needle-like structures – known as dendrites and whiskers – that plague lithium batteries, sometimes causing a short circuit, failure, or even a fire. Such defects are a major factor holding back the batteries from even more widespread use and further improvement.

The team, led by Chongmin Wang at the Department of Energy’s Pacific Northwest National Laboratory, has shown that the presence of certain compounds in the electrolyte – the liquid material that makes a battery’s critical chemistry possible – prompts the growth of dendrites and whiskers. The team hopes the discovery will lead to new ways to prevent their growth by manipulating the battery’s ingredients.

The results have been published in Nature Nanotechnology.

Dendrites are tiny, rigid tree-like structures that can grow inside a lithium battery; their needle-like projections are called whiskers. Both cause tremendous harm; notably, they can pierce a structure known as the separator inside a battery, much like a weed can poke through a concrete patio or a paved road. They also increase unwanted reactions between the electrolyte and the lithium, speeding up battery failure.

Dendrites and whiskers are holding back the widespread use of lithium metal batteries, which have higher energy density than their commonly used lithium-ion counterparts.

The PNNL team found that the origin of whiskers in a lithium metal battery lies in a structure known as the “SEI” or solid-electrolyte interphase, a film where the solid lithium surface of the anode meets the liquid electrolyte. Further, the scientists pinpointed a culprit in the growth process: ethylene carbonate, an indispensable solvent added to electrolyte to enhance battery performance.

It turns out that ethylene carbonate leaves the battery vulnerable to damage.

The team’s findings include videos that show the step-by-step growth of a whisker inside a nanosized lithium metal battery specially designed for the study.

A dendrite begins when lithium ions start to clump, or “nucleate,” on the surface of the anode, forming a particle that signifies the birth of a dendrite. The structure grows slowly as more and more lithium atoms glom on, growing the same way that a stalagmite grows from the floor of a cave. The team found that the energy dynamics on the surface of the SEI push more lithium ions into the slowly growing column. Then, suddenly, a whisker shoots forth.

It wasn’t easy for the team to capture the action. To do so, scientists integrated an atomic force microscope (AFM) and an environmental transmission electron microscope (ETEM), a highly prized instrument that allows scientists to study an operating battery under real conditions.

The team used the AFM to measure the tiny force of the whisker as it grew. Much like a physician measures a patient’s hand strength by asking the patient to push upward against the doctor’s outstretched hands, the PNNL team measured the force of the growing whisker by pushing down on its tip with the cantilever of the AFM and measuring the force the dendrite exerted during its growth.

The team found that the level of ethylene carbonate directly correlates with dendrite and whisker growth. The more of the material the team put in the electrolyte, the more the whiskers grew. The scientists experimented with the electrolyte mix, changing ingredients in an effort to reduce dendrites. Some changes, such as the addition of cyclohexanone, prevented the growth of dendrites and whiskers.

“We don’t want to simply suppress the growth of dendrites; we want to get to the root cause and eliminate them,” said Wang, a corresponding author of the paper along with Wu Xu. “We drew upon the expertise of our colleagues who have expertise in electrochemistry. My hope is that our findings will spur the community to look at this problem in new ways. Clearly, more research is needed.”

Understanding what causes whiskers to start and grow will lead to new ideas for eliminating them or at least controlling them to minimize damage, added first author Yang He. He and the team tracked how whiskers respond to an obstacle, either buckling, yielding, kinking, or stopping. A greater understanding could help clear the path for the broad use of lithium metal batteries in electric cars, laptops, mobile phones, and other areas.

This is welcome news indeed. Lithium is such a huge improvement over the older battery chemistries product designers and consumers have tolerated the risks. Product designers and engineers have made lithium ion much safer than when they first appeared, but the risk is still there.

Lithium metal, with much more capacity than the lithium ion type, has been left out of the market due to the risks. So far the fire risk to too great even for the most daring.

If this team has the handle on why the whiskers and dendrites occur then is just a matter of time for alternatives to be found. That’s when the new better and hopefully cheaper lithium metal battery can get to market.

University of Oregon researchers used an atomic-force microscope fitted with an electrode tip 1,000 times smaller than a human hair to identify in real time how nanoscale catalysts collect charges that are excited by light in semiconductors. It’s a discovery that could help efforts to design devices that can store solar power for later use.

In their paper published in the journal Nature Materials, they discovered that as the size of the catalytic particles shrinks below 100 nanometers the collection of excited positive charges (holes) becomes much more efficient than the collection of excited negative charges (electrons). This phenomenon prevents the excited positive and negative charges from recombining and thus increases the system efficiency.

Tiny electrode tip moves over the interface of nickel nanoparticles on a silicon wafer. Image Credit: Shannon Boettcher, University of Oregon . Click image for the largest view.

The findings open the door to improving systems that use light to make chemicals and fuels, for example by splitting water to make hydrogen gas or by combining carbon dioxide and water to make carbon-based fuels or chemicals, said Shannon W. Boettcher, a professor in the UO’s Department of Chemistry and Biochemistry and member of the university’s Materials Science Institute.

Boettcher expands, “We found a design principle that points to making catalytic particles really small because of the physics at the interface, which allows one to increase efficiency. Our technique allowed us to watch the flow of excited charges with nanometer-scale resolution, which is relevant for devices that use catalytic and semiconductor components to make hydrogen that we can store for use when the sun is not shining.”

In the research, Boettcher’s team used a model system consisting of a well-defined single-crystal silicon wafer coated with metallic nickel nanoparticles of different sizes. The silicon absorbs sunlight and creates excited positive and negative charges. The nickel nanoparticles then selectively collect the positive charges and speed up the reaction of those positive charges with electrons in water molecules, pulling them apart.

Previously, Boettcher said, researchers could only measure the average current moving across such a surface and the average voltage generated by the light hitting the semiconductor. To look closer, his team collaborated with Bruker Nano Surfaces, the manufacturer of the UO’s atomic force microscope that images the topography of surfaces by tapping a sharp tip over it – much like a blind person tapping their cane – to develop the techniques needed to measure voltage at the nanoscale.

As the electrode tip touched each of the nickel nanoparticles, the researchers were able to record the buildup of holes by measuring a voltage – similar to how one tests the voltage output from a battery.

Surprisingly, the voltage measured as the device was operating depended strongly on the size of the nickel nanoparticle. Small particles were able to better select for the collection of excited positive charges over negative charges, reducing the rate of charge recombination and generating higher voltages that better split apart water molecules.

A key, Boettcher said, is that oxidation at the nickel nanoparticle surface leads to a barrier, much like overlapping ridges in a mountain valley, that prevents the negatively charged electrons from flowing to the catalyst and annihilating the positively charged holes. This effect has been termed “pinch-off” and was hypothesized to occur in solid-state devices for decades but never before directly observed in fuel-forming photoelectrochemical systems.

The study’s lead author Forrest Laskowski, who was a National Science Foundation graduate research fellow in Boettcher’s lab, said, “This new technique is a general means to investigate the state of nanoscale features in electrochemical environments. While our results are useful for understanding photoelectrochemical energy storage, the technique could more broadly be applied to study electrochemical processes in actively-operating systems such as fuels cells, batteries, or even biological membranes.”

This work is quite interesting as the word platinum is absent. The potential for hydrogen depends in a major way to getting around the huge cost platinum catalysts load into the hydrogen economy. Platinum used at scale would skyrocket the price of the element.

That makes the innovative use of new tools crucial for more progress. The innovation and drive this team has shown is welcomed with thanks as hydrogen seems to have stalled a bit and needs more progress – if only to light a fire under the effort to find a way to store the universe’s smallest atom.


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