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 m 2 /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 CO 2 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 CO 2 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