Tag: carbon dioxide

Building a better carbon capture system

Building a better carbon capture system

Carbon capture has been hailed as a ground-breaking technology for cleaning the air. And it is, but there are some drawbacks – it’s expensive, and most technology requires the generation and application of heat, which creates emissions.

There had to be a better way, thought Dr. Haotian Wang, associate professor in the Department of Chemical and Biomolecular Engineering at Rice University at Houston, Texas.

Wang and his team found it in a process of electrolysis they studied at Rice and collaborated on with the Canadian Light Source (CLS) at the University of Saskatchewan. They have devised a modular solid electrolyte reactor that, in time, will be usable everywhere, in industry but also for “household use, small business use, space station, submarine, any enclosed environment,” he said. Their study was published in the journal Nature.

“Our new approach is integrated capture and regeneration, which means that you can continuously concentrate the carbon dioxide from dilute sources into almost 100 percent purity.”

The reactor is divided into three chambers. Electrolysis, a process by which electric current is passed through a substance to effect a chemical change, occurs on two sides — one performing oxygen reduction and the other oxygen evolution. The oxygen reduction reaction creates an alkaline environment, which captures carbon and then releases it in the central chamber.

The carbon can either be stored underground or converted to valuable products such as alcohols, “which is also an important direction we are working on,” Wang said.

Crucially, no chemical inputs other than water are required and no side products are generated.

Wang has estimated that the cost of capturing carbon will be $83 per ton, but with improvements, that could drop to $58 or even $33 per ton, a big saving from today’s costs, which range from $125 to $600 USD.

“It’s not only the cost but also the energy source that we can use, which is electricity,” he said. “Ideally, we want to transform this into an electrifying process because in the future we can get a lot (of clean electricity) from solar farms, wind farms and nuclear power plants.”

The CLS played an important role in this work.

Read more on the CLS website

Understanding How the Structure of Boron Oxynitride Affects its Photocatalytic Properties

Understanding How the Structure of Boron Oxynitride Affects its Photocatalytic Properties

Synchrotron studies show that tuning the synthesis of boron oxynitride can improve its performance as a photocatalyst and semiconductor

Carbon dioxide (CO2) is often in the news these days. As a greenhouse gas, released during the combustion of fossil fuels, it is fuelling climate change, and reducing our CO2 emissions is critical to a sustainable future. CO2 is also a by-product of many industrial processes, including the production of ammonia used for fertilisers. On the other hand, many industries need a regular supply of CO2, and shortages have caused problems in recent years. It makes sense, therefore, to find ways to recycle some of the waste CO2 we produce into useful products. However, CO2 conversion reactions are energy-intensive, and new catalysts are needed to make the reactions more efficient. Photocatalysts absorb light energy, creating a charge separation that can then drive a chemical reaction. A team of researchers from Imperial College London are researching CO2 conversion using photocatalysis. In work recently published in Chemistry of Materials, they investigated how oxygen doping affects the photocatalytic and optoelectronic properties of boron nitride. Their results provide valuable insights into the photochemistry of boron oxynitride (BNO) at the fundamental level.

By clarifying the importance of paramagnetism in BNO semiconductors and providing fundamental insight into their photophysics, this study paves the way to tailoring its properties for CO2 conversion photocatalysis. The group has also recently used a similar methodology to investigate phosphorus doping of boron nitride, which they will explore in a future publication. 

Read more on the Diamond Light Source website

Image: Combined experimental (EPR, NEXAFS) + computational study (DFT)

Credit: Image via Chem. Mater. 2023, 35, 5, 1858-1867

Synthesised a new catalyst with key properties to solve environmental issues

Synthesised a new catalyst with key properties to solve environmental issues

A research led by the ITQ-CSIC-UPV has discovered a new catalyst enabling hydrogenation of carbon dioxide to methane with advantages not seen until now. This new catalyst, whose structure and mechanism have been understood by synergistically exploiting different ALBA Synchrotron techniques, can be used for methane (natural syngas) production, that is considered as a promising energy carrier for hydrogen storage.

Linear economy has proven to be unsustainable in the long run due to its ineffective use of natural resources that leads to a huge amount of greenhouse gas emissions and waste generation. An alternative model, the so-called circular economy is based on an efficient production cycle that focuses on minimising waste and better recycling and seems to be key to find solutions for the climate crisis. One process that can be essential in this challenge is carbon dioxide (CO2) sequestration and usage, that is, transform atmospheric or produced carbon dioxide into energy carriers or platform molecules of the chemical industry.

An international collaboration between the Instituto de Tecnología Química – a join research center between Consejo Superior de Investigaciones Científicas and Universitat Politècnica de València (ITQ-CSIC-UPV), SOLEIL Synchrotron, Universidad de Cádiz, and ALBA Synchrotron permitted to synthesize a new catalyst able to hydrogenate carbon dioxide to methane with significant improvements in comparison to existing analogues. Its main advantage is that it possesses a much higher activity and so the reaction temperature can be lowered from usual 270-400ºC to only 180ºC, with an excellent long-term stability. Furthermore, this catalyst is able to operate under intermittent power supply conditions, which couples very well with electricity production systems based on renewable energies. Moreover, its synthetic procedure itself is ecofriendly, making it an even greater option in environmental issues.

This new catalyst can be used for methane (natural syngas) production, that is considered as a promising energy carrier for hydrogen storage.

The new solid catalyst was designed and synthesized in the ITQ (CSIC-UPV) by a mild, green hydrothermal synthesis procedure resulting in a material that contains interstitial carbon atoms doped in the ruthenium (Ru) oxide crystal lattice, enabling the stabilization of Ru cations in a low oxidation state with the formation of a none yet reported ruthenium oxy-carbonate phase.

Read more on ALBA website

How a record-breaking copper catalyst converts CO2 into liquid fuels

How a record-breaking copper catalyst converts CO2 into liquid fuels

Researchers at Berkeley Lab, collaborating with CHESS scientists at the PIPOXS beamline, have made the first real-time movies of copper nanoparticles as they evolve to convert carbon dioxide and water into renewable fuels and chemicals. Their new insights could help advance the next generation of solar fuels.

Since the 1970s, scientists have known that copper has a special ability to recycle carbon dioxide into valuable chemicals and fuels. But for many years, scientists have struggled to understand how this common metal works as an electrocatalyst, a mechanism that uses energy from electrons to chemically transform molecules into different products.

Now, a research team led by Lawrence Berkeley National Laboratory (Berkeley Lab) has gained new insight by capturing the world’s first real-time movies of copper nanoparticles (copper particles engineered at the scale of a billionth of a meter) as they convert CO2 and water into renewable fuels and chemicals: ethylene, ethanol, and propanol, among others. The work was reported in the journal Nature.

“This is very exciting. After decades of work, we’re finally able to show – with undeniable proof – how copper electrocatalysts excel in CO2 reduction,” said Peidong Yang, a senior faculty scientist in Berkeley Lab’s Materials Sciences and Chemical Sciences Divisions who led the study. Yang is also a professor of chemistry and materials science and engineering at UC Berkeley. “Knowing why copper is such an excellent electrocatalyst brings us steps closer to turning CO2 into new, renewable solar fuels through artificial photosynthesis.”

Read more on the CHESS website

Image: Artist’s rendering of a copper nanoparticle as it evolves during CO2 electrolysis: Copper nanoparticles (left) combine into larger metallic copper “nanograins” (right) within seconds of the electrochemical reaction, reducing CO2 into new multicarbon products.

Credit: Yao Yang/Berkeley Lab

Electrocatalysis – Iron and Cobalt Oxyhydroxides examined

Electrocatalysis – Iron and Cobalt Oxyhydroxides examined

A team led by Dr. Prashanth W. Menezes (HZB/TU-Berlin) has now gained insights into the chemistry of one of the most active anode catalysts for green hydrogen production. They examined a series of Cobalt-Iron Oxyhydroxides at BESSY II and were able to determine the oxidation states of the active elements in different configurations as well as to unveil the geometrical structure of the active sites. Their results might contribute to the knowledge based design of new highly efficient and low cost catalytical active materials.

Very soon, we need to become fossil free, not only in the energy sector, but as well in industry. Hydrocarbons or other raw chemicals can be produced in principle using renewable energy and abundant molecules such as water and carbon dioxide with the help of electrocatalytically active materials. But at the moment, those catalyst materials either consist of expensive and rare materials or lack efficiency.

Key reaction in water splitting

A team led by Dr. Prashanth W. Menezes (HZB/TU-Berlin) has now gained insights into the chemistry of one of the most active catalysts for the anodic oxygen evolution reaction (OER), which is a key reaction to supply electrons for the hydrogen evolution reaction (HER) in water splitting. The hydrogen can then be processed into further chemical compounds, e.g., hydrocarbons. Additionally, in the direct electrocatalytic carbon dioxide reduction to alcohols or hydrocarbons, the OER also plays a central role.

Read more on the HZB website

Image: LiFex-1Cox Borophosphates have been used as inexpensive anodes for the production of green hydrogen. Their dynamic restructuring during OER as well as their catalytically active structure, have been elucidated via  X-ray absorption spectroscopy.

Credit: © P. Menezes / HZB /TU Berlin

How a soil microbe could rev up artificial photosynthesis

How a soil microbe could rev up artificial photosynthesis

Researchers discover that a spot of molecular glue and a timely twist help a bacterial enzyme convert carbon dioxide into carbon compounds 20 times faster than plant enzymes do during photosynthesis. The results stand to accelerate progress toward converting carbon dioxide into a variety of products.

Plants rely on a process called carbon fixation – turning carbon dioxide from the air into carbon-rich biomolecules ­– for their very existence. That’s the whole point of photosynthesis, and a cornerstone of the vast interlocking system that cycles carbon through plants, animals, microbes and the atmosphere to sustain life on Earth. 

But the carbon fixing champs are not plants, but soil bacteria. Some bacterial enzymes carry out a key step in carbon fixation 20 times faster than plant enzymes do, and figuring out how they do this could help scientists develop forms of artificial photosynthesis to convert the greenhouse gas into fuels, fertilizers, antibiotics and other products.

Now a team of researchers from the Department of Energy’s SLAC National Accelerator Laboratory, Stanford University, Max Planck Institute for Terrestrial Microbiology in Germany, DOE’s Joint Genome Institute (JGI) and the University of Concepción in Chile has discovered how a bacterial enzyme – a molecular machine that facilitates chemical reactions – revs up to perform this feat.

Rather than grabbing carbon dioxide molecules and attaching them to biomolecules one at a time, they found, this enzyme consists of pairs of molecules that work in sync, like the hands of a juggler who simultaneously tosses and catches balls, to get the job done faster. One member of each enzyme pair opens wide to catch a set of reaction ingredients while the other closes over its captured ingredients and carries out the carbon-fixing reaction; then, they switch roles in a continual cycle.  

Read more on the SLAC website

Helping to neutralise greenhouse gases

Helping to neutralise greenhouse gases

Researchers used the Canadian Light Source (CLS) at the University of Saskatchewan to create an affordable and efficient electrocatalyst that can transform CO2 into valuable chemicals. The result could help businesses as well as the environment.

Electrocatalysts help to collect CO2 pollution and efficiently convert it into more valuable carbon monoxide gas, which is an important product used in industrial applications. Carbon monoxide gas could also help the environment by allowing renewable fuels and chemicals to be manufactured more readily.

The end goal would be to try to neutralize the greenhouse gases that worsen climate change.

Precious metals are often used in electrocatalysts, but a team of scientists from Canada and China set out to find a less expensive alternative that would not compromise performance. In a new paper, the stability and energy efficiency of the team’s novel electrocatalyst offered promising results.

Read more on the Canadian Light Source website

Image : Schematic of an electrochemistry CO2-to-CO reduction reaction.