Environmental CO2 Capture by Amyloid Fibers and Amino-Functionalized Metal-Organic Frameworks

ALEJANDRO M. FRACAROLI, HIROYASU FURUKAWA, DAN LI, HEXIANG DENG, CONG LIU, DAVID EISENBERG, OMAR M. YAGHI

San Francisco, California

Congreso; 2014 Materials Research Society Meeting and Exhibit; 2014

Materials Research Society

Carbon dioxide produced by burning fossil fuels is believed to be a main contributor to climate change. To stabilize CO2 emissions at 1990 levels, it is necessary to couple new CO2 scrubbing systems to power plants and automobiles. One of the most important drawbacks in the currently industrial usage of monoethanolamine (MEA) is the high heat capacity of aqueous MEA solutions, since the energy input required for solvent regeneration can consume up to 70% of the total operating cost in a CO2 capture plant. To overcome the high energy consumption for solvent regeneration, solid adsorbents such as zeolites, activated carbons and metal-organic frameworks (MOFs) have been extensively exploited. Nevertheless, the CO2 uptake capacity of most of these materials drops in the presence of water, one of the main components of the flue gas.Here we demonstrate that amyloids, self-assembling protein fibers, and amino-functionalized MOFs are effective for selective CO2 capture in the presence of moisture. We found that VQIVYK fibers are sufficiently open to allow the diffusion of small gaseous molecules, based on N2 adsorption measurements at 77 K. The amount of CO2 sorbed in the fibers was found to be one molecule per peptide. In addition, cross-polarization magic-angle-spinning (CP/MAS) 13C-NMR allowed us to conclude about the formation of carbamate during the uptake process and to demonstrate the reversibility of the reaction at 100 °C. Breakthrough experiments showed a capacity of kinetic CO2 adsorption of 0.48 mmol/g that was maintained even after introducing 3 wt% of water into the gas feed stream. These results inspired the design and preparation of a series of functionalized IRMOF-74-III structures with aromatic, primary and secondary amines covalently attached to the organic linkers. The CO2 sorption behavior and the energy required to regenerate these systems demonstrate the importance of an available the strategy to introduce customized functional groups in the architectured pore environments.