Applicability of linear polyethylenimine supported on nano-silica for the adsorption of CO2 from various sources including dry air

作者：Zhang Hang; Goeppert Alain^*; Prakash G K Surya; Olah George

来源：RSC Advances, 2015, 5(65): 52550-52562.

DOI：10.1039/c5ra05428a

Adsorbents based on linear polyethylenimines (LPEIs) supported on fumed silica were prepared and studied for the reversible adsorption of CO2 under mild conditions from various gas mixtures, including dry air with a CO2 concentration of only 400 ppm. While the adsorption kinetics were similar between linear and branched PEI impregnated on fumed silica, the desorption rate was noticeably faster on linear PEI, which is advantageous for fast adsorption/desorption cycling. The enthalpy of CO2 adsorption was also lower on LPEI based adsorbents (-43 to -53 kJ mol(-1) CO2). Desorption of the adsorbed CO2 occurred rapidly at relatively low temperatures (50 to 100 degrees C). The adsorption/desorption process can be repeated for more than one hundred cycles with no noticeable decrease in adsorption capacity even under humid conditions. The stability of the adsorbents under CO2, air, and N-2 was also investigated.

• 出版日期2015