UC Irvine

With the increase of CO2 and other greenhouse gases emissions into the atmosphere, research into methods to mitigate these emissions is gaining more attention. The use of various capture agents to absorb CO2 from either waste gas streams or directly from air can lead to completely carbon-neutral or carbon-negative technologies. This work studies two new methods for CO2 capture: a direct capture method using alkoxides, and an indirect capture method using photoacids for creating localized pH swings. CO2 capture using alkoxides was verified through the formation of alkyl carbonates. The CO2 absorption capacity was then measured for each alkoxide synthesized or purchased, showing a general trend for higher CO2 absorption capacity correlating with higher pKa values. The effect of the counter cation for alkoxides in CO2 capture was also investigated, showing that changing the counter cation does in fact alter CO2 absorption capacity for hydroxide (0.39-0.85 mole CO2 absorbed per mole of hydroxide). The second capture system investigated used photoexcitation of photoacids to release captured CO2 from solution. The initial setup to test CO2 capture and release for this system shows effective CO2 capture into solution and release of CO2 after the photoacid is excited. However, this process’s efficiency could be improved through use of a higher intensity photon source.