Preparation of CO2 adsorbent with N1-(3-(trimethoxysilyl)propyl)-1,3-propanediamine and its performance

N1-(3-(trimethoxysilyl)propyl)-1,3-propanediamine (2NS-P), a diaminosilane having a propyl spacer between the two amino groups was successfully synthesized, and a CO2 adsorbent functionalized with 2NS-P was prepared via impregnation of it into silica. The adsorption performance and stability of 2NS-P/Kona95 were examined and compared to that of N1-(3-(trimethoxysilyl)propyl)ethane-1,2-diamine (2NS)/Kona95 having an ethyl spacer. 2NS-P/Kona95 exhibited better CO2 adsorption capacity and CO2/N efficiency. The adsorbents were subjected to ten cycles of temperature swing adsorption (TSA), demonstrating that stability of 2NS-P/Kona95 was better than that of 2NS/Kona95. The spent 2NS-P/Kona95 showed the absence of cyclic urea formation in FT-IR spectrum, explaining the better stability of 2NS-P/Kona95 than 2NS/Kona95.