The new porous material for capturing carbon dioxide, called a covalent organic framework (COF), has hexagonal channels decorated with polyamines that efficiently bind CO2 molecules (blue and orange balls) at concentrations found in ambient air. (Graphic credit: Chaoyang Zhao)
Capturing and storing the carbon dioxide humans produce is key to lowering atmospheric greenhouse gases and slowing global warming, but today’s carbon capture technologies work well only for concentrated sources of carbon, such as power plant exhaust. The same methods cannot efficiently capture carbon dioxide from ambient air, where concentrations are hundreds of times lower than in flue gases.
Yet direct air capture, or DAC, is being counted on to reverse the rise of CO2 levels, which have reached 426 parts per million (ppm), 50% higher than levels before the Industrial Revolution. Without it, according to the Intergovernmental Panel on Climate Change, we won’t reach humanity’s goal of limiting warming to 1.5 °C (2.7 °F) above preexisting global averages.
A new type of absorbing material developed by chemists at the University of California, Berkeley, could help get the world to negative emissions. The porous material — a covalent organic framework (COF) — captures CO2 from ambient air without degradation by water or other contaminants, one of the limitations of existing direct air capture technologies.
The new promising COF-999 material was developed by the Yaghi group at the Colege of Chemistry. The characterization of COFs can be elusive due to amorphous nature of these materials and it often requires complimentary approachesa. In this case, critical information about the COF-999 material, such as the functional groups within its pores, degree of its polymerization, and binding of CO2 molecules by COF-999 were determined using cross-polarization magic-angle spinning (CP-MAS) solid-state Nuclear Magnetic Resonance spectroscopy applications at the PMRC Core. The results were published in the journal Nature.