Colloquium: Dr. Ongun Ozcelik, Princeton University
I will focus on CO2 emissions of power plants which is a major factor contributing to global warming. There exists alternative energy technologies which try to overcome this problem however most of the future energy scenarios still rely on the use of conventional fuel-based energy sources. Designing a novel CO2 adsorbent material is a key factor which can revolutionize the current state of technology. In this talk, I will show that based on theoretical analysis comprised of ab-initio quantum mechanical calculations and force-field molecular dynamics simulations, we have predicted the existence of an ultra-thin material (portlandene) which can be used as a CO2 capturing material in current combustion plants. I will show that this single-layer phase is robust and maintains its stability even at high temperatures. The chemical activity of portlandene is seen to further increase upon defect engineering its surface using vacancy sites. Defect-containing portlandene is capable of separating CO and CO2 from a syngas (CO/CO2/H2) stream, yet is inert to water vapor. This selective behavior and the associated mechanisms have been elucidated by examining its electronic structure, local charge distribution and bonding orbitals. Additionally, unlike conventional CO2 capturing technologies, the regeneration process of portlandene does not require high temperature heat treatment since it can release the captured CO2 by application of a mild external electric field, making portlandene an ideal capturing material both in pre- and post-combustion processes.