A New Avenue in Ca2+ Ion-Exchanged A-Type Zeolite Chemistry
Credit?2021 Okayama University-InorgChem
Scientists report hitherto unobserved high-performance CO2 adsorption in zeolites at room temperature, opening doors to applications in air purification
Reducing the amount of CO2 in our environment is crucial for mitigating climate change and needs materials that can adsorb CO2 from air under ambient conditions. In a new study, scientists from Japan explore the CO2 adsorption properties of zeolite, which has been overlooked in this regard, and report an unprecedented selective adsorption behavior in the extremely lower pressure region and at room temperature, paving the way for its future applications in air purification.
It is now well known that carbon dioxide is the biggest contributor to climate change and originates primarily from burning of fossil fuels. While there are ongoing efforts around the world to end our dependence on fossil fuels as energy sources, the promise of green energy still lies in the future. Can something be done in the meantime to reduce the concentrations of CO2 in the atmosphere?
It would, in fact, be great if the CO2 in the atmosphere could simply be adsorbed! Turns out, this is exactly what direct air capture (DAC), or the capture of CO2 under ambient conditions, aims to do. However, no such material with the ability to adsorb CO2 efficiently under DAC conditions has so far been developed. “It is well known that CO2 is acidic in nature. Therefore, materials with basic nature are generally utilized as adsorbents for CO2. However, that often leads to corrosion of the system and is also not suitable for recycling the adsorbed CO2,” explains Professor Yasushige Kuroda from Okayama University, Japan, who conducts research on surface chemistry.
Against this backdrop, in a recent study published in the Journal of Materials Chemistry A, scientists from Okayama University and Japan Synchrotron Radiation Research Institute (JASRI) led by Prof. Kuroda explored the adsorption properties of a material that has so far remained an “underdog”: zeolites (minerals containing mainly aluminum and silicon oxides). “Zeolite materials have received little attention as adsorbents owing to their low CO2 adsorption capacity at room temperature and in the lower pressure adsorption region, as well as their poor selectivity over nitrogen,” says Prof. Kuroda.
In their study, Prof. Kuroda and his team designed an ion-exchanging method of zeolite with alkaline-earth ions and achieved a remarkably high CO2 adsorption under ambient conditions. The team specifically chose an A-type zeolite (silicon/aluminum ratio of 1) because of its appropriate pore size for adsorbing CO2, while the alkaline-earth ion exchange imparted a large electric field strength that, supposedly, acted as a driving force for the adsorption. Scientists chose a doubly charged calcium ion (Ca2+) as the exchange ion since it allowed for the greatest amount of adsorption. In fact, the adsorbed volume noted was the largest amount of CO2 to have ever been adsorbed by any zeolite system, surpassing that for other materials under similar conditions!
To investigate the underlying adsorption mechanism, the scientists carried out far-infrared (far-IR) measurements and backed them up with density functional theory (DFT) calculations. The far-IR spectra, which detected the vibrational modes due to Ca2+-zeolite vibration, showed a distinct shift towards longer wavelengths following CO2 adsorption, a feature scientists could not recognize in other samples, e.g. Na-ion exchanged A-type zeolite. They further verified their observation with a model that showed good agreement with DFT calculations.
Moreover, the scientists were able to completely desorb the adsorbed CO2 and recover the original sample and its specific adsorption properties. In addition, the sample showed a superior selective adsorption of CO2 from other gases after the scientists examined the separation of CO2 using a model gas that emulated ambient air in its composition.
The findings thus bring zeolites to the forefront as an efficient adsorbent of CO2 under ambient conditions, a feat previously thought unachievable with these systems. “Our work can open doors to potentially novel applications of zeolites, such as in the cleaning of air inside semi-closed spaces including space shuttles, submarines, and concert halls, and as an adsorbent material in the anesthetic process,” speculates Prof. Kuroda excitedly.
One thing is for sure, though: chemists will never look at zeolite in the same way again.
Original Article: Zero to Hero: Overlooked Material Could Help Reduce Our Carbon Footprint
More from: Okayama University
The Latest Updates from Bing News & Google News
Go deeper with Bing News on:
Zeolites
- Bio-inspired materials' potential for efficient mass transfer boosted by a new twist on a century-old theory
The natural vein structure found within leaves—which has inspired the structural design of porous materials that can maximize mass transfer—could unlock improvements in energy storage, catalysis, and ...
- Ecovyst Reports First Quarter 2024 Results
Ecovyst Inc. (NYSE: ECVT) ("Ecovyst" or the "Company"), a leading integrated and innovative global provider of advanced materials, specialty catalysts and services, today reported results for the ...
- Advanced nuclear magnetic resonance technique reveals precise structural, dynamical details in zeolites
Zeolites are widely used in many industries, yet their intrinsic catalytic nature is not completely understood, due to the complexity of the hydroxyl-aluminum moieties. Atomic-scale analysis of ...
- Zeolites in Pre-Caldera Pyroclastic Rocks of the Santorini Volcano, Aegean Sea, Greece
Mordenite postdates the heulandite-group zeolites and opal-CT. Some mordenite has replaced the rims of glass shards. The alteration minerals are not related to vertical or lateral zonation, and the ...
- 'Most challenging' nuclear clear-up starts
Zeolites were placed in the pond in the 1970s and 80s to help absorb radiation. This is the first nuclear waste to be put into a new, British-made storage container - known as a self-shielded box ...
Go deeper with Google Headlines on:
Zeolites
[google_news title=”” keyword=”zeolites” num_posts=”5″ blurb_length=”0″ show_thumb=”left”]
Go deeper with Bing News on:
CO2 adsorption
- CO2 - Weather warnings issued
Tonight is expected to remain dry with a mix of clear spells and some patches of low cloud drifting in from the south-east, especially during the early hours. Sunday Tomorrow morning will see any ...
- Innovative activated carbon from palm kernel shells enhances methane storage
The team aimed to improve the adsorptive properties of AC for methane storage by experimenting with different activation agents, including steam, carbon dioxide (CO 2), and ... with the methane ...
- Linde to build $150m ASU for world’s first large-scale green steel plant
Linde revealed today that it will invest $150m into an on-site air separation unit (ASU) in Boden, northern Sweden, to supply industrial gases to the world’s first large-scale green steel production ...
- Carbon capture tech makes oilfield go greener
"Compared to overcoming high-temperature and high-pressure technology, overcoming the corrosion of the wellbore is the most critical issue," Luan said. Once the injected carbon dioxide encounters ...
- The Dirtiest Side of EVs: Rare Earths and Conflict Metals
"Typical mining operations for rare earth mines vary from hard rock to heavy-mineral sands and ionic adsorption clay operations," de Jonge said. "For hard rock assets (the most common), metallurgy is ...
Go deeper with Google Headlines on:
CO2 adsorption
[google_news title=”” keyword=”CO2 adsorption” num_posts=”5″ blurb_length=”0″ show_thumb=”left”]