Carbon Dioxide Capture from Ambient Air Using Amine-Grafted Mesoporous Adsorbents

Figure 4

FTIR (DRIFT) spectra in the region 1300–1900 cm⁻¹ of the TRI adsorbent material as functions of adsorption and desorption conditions and the number of cycles: (a) fresh, (b) outdoor, 100°C humid air, 3 cycles, and (c) TGA, 120°C dry air, 10 cycles. Further experimental details listed in Table 1. The band at ~1660–1670 cm⁻¹ and the shoulder at ~1490 cm⁻¹ are both assigned to urea groups and the band at 1600 cm⁻¹ to NH₂.