Amine-functionalization of the nanotitanate ETS-2



A series of nonporous, amine-functionalized sodium titanates was prepared and the thermal and adsorptive behavior of the samples were characterized. Engelhard titanosilicate 2 was chosen as a substrate for its high surface area (∼300 m2/g), native surface hydroxyl concentration, and lack of microporosity; eliminating the risk of fouling the adsorbent under certain process conditions. Aminosilanes containing a single (N1), two (N2), and three (N3) amine groups were chemically grafted to the surface of the substrate and the adsorption capacity for CO2 measured through thermogravimetry-mass spectroscopy (TG-MS) desorption, volumetric adsorption, and gravimetric adsorption/desorption cycling. The N3 sample displayed complete monolayer coverage and was capable of adsorbing five times as much atmospheric CO2 as the N1 sample. Testing under anhydrous conditions only engages the primary amine on the tether and the data consistently suggests a correlation between amine utilization and the proportion of monolayer coverage for these adsorbents. © 2013 American Institute of Chemical Engineers AIChE J, 59: 4727–4734, 2013