Muhammad Sahimi
University of Southern California, CA·Engineering
Pulling carbon dioxide (CO2) straight out of the air, known as direct air capture, is one route to reducing greenhouse gases already in the atmosphere. The problem is energy.
- Fields
Engineering
Materials Science
Chemistry
- Topics
direct air capture
carbon dioxide capture
CO2 adsorption
- Grants
- 1 known grant, through Jul 2027
What they work on
- Characterize the intermolecular attractions that permit low-energy CO2 release from Fe3O4 magnetic nanoparticle composites under an external magnetic field, probing how far the field perturbs electron transfer using electron paramagnetic resonance spectroscopy and density functional theory.
- Determine how trade-offs between heat capacity and magnetization in Fe3O4/MOF-amine and Fe3O4/SiO2-amine sorbents affect diffusive heat and molecular transport, using frequency-domain thermoreflectance and molecular dynamics simulations.
- Elucidate the magnetic-field-triggered CO2 transport mechanisms during sorbent regeneration in the presence of oxygen, nitrogen and water, using zero-length column and magnetic induction swing adsorption experiments.
More about the research
Air contains very little CO2, so the usual gas-separation tricks of swinging pressure or temperature work badly here. Today's capture materials, usually based on amines (nitrogen-containing molecules that grab CO2) or ionic liquids, also take a lot of energy to release the captured CO2 and be reused. Worse, most of these materials conduct heat poorly, so heating them from the outside wastes much of the energy. This project studies a different idea: sorbent materials that release their CO2 when a magnetic field is applied.
Why it matters
If sorbents can be regenerated by a magnetic field instead of bulk heating, direct air capture could run on far less energy, which is currently the main barrier to deploying it at the scale that matters for climate. The mechanistic understanding sought here, of how heat and CO2 move inside these composites in the presence of water, oxygen and nitrogen, could guide design of cheaper low-energy capture systems.
Known grants
From NIH and NSF research grants. Labs often have other funding we can't see.
Closest labs
Tanya Hutter
University of Texas at Austin, TX·Engineering·Early-career
Develop methods to embed porous gas-adsorbing materials inside 3D microstructured silicon substrates with high thermal conductivity, and characterize how the adsorbent interacts with the substrate surface.
Richard Liu
Harvard University, MA·Chemistry·Early-career
Demonstrate that organic, metal-free "pseudometal" catalysts can perform oxidative addition and reductive elimination, then assemble these steps into catalytic cycles that mimic palladium-catalyzed cross-coupling.
Pratik Dholabhai
Rochester Institute of Technology, NY·Materials Science·Early-career
Build a multiscale computational framework for the CaO + CO2 ⇌ CaCO3 looping cycle, and validate it with atomic-resolution and in situ gas-cell transmission electron microscopy, which images reactions as they happen.
The school
University of Southern California: 47 labs on PI Pages, $1.3B a year on research, 882 research doctorates a year.
Reach out
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