Department of Chemistry, Centre for Catalysis Research and Innovation (CCRI), University of Ottawa , Ottawa, Ontario, Canada K1N 6N5.
Environ Sci Technol. 2014;48(3):2025-34. doi: 10.1021/es404135j. Epub 2014 Jan 24.
Tertiary amine containing poly(propyleneimine) second (G2) and third (G3) generation dendrimers as well as polyethyleneimine (PEI) were developed for the selective removal of SO2. N-Alkylation of primary and secondary amines into tertiary amines was confirmed by FTIR and NMR analysis. Such modified polyamines were impregnated on two nanoporous supports, namely, SBA-15PL silica with platelet morphology and ethanol-extracted pore-expanded MCM-41 (PME) composite. In the presence of 0.1% SO2/N2 at 23 °C, the uptake of modified PEI, G2, and G3 supported on SBA-15PL was 2.07, 2.35, and 1.71 mmol/g, respectively; corresponding to SO2/N ratios of 0.22, 0.4, and 0.3. Under the same conditions, the SO2 adsorption capacity of PME-supported modified PEI and G3 was significantly higher, reaching 4.68 and 4.34 mmol/g, corresponding to SO2/N ratios of 0.41 and 0.82, respectively. The working SO2 adsorption capacity decreased with increasing temperature, reflecting the exothermic nature of the process. The adsorption capacity of these materials was enhanced dramatically in the presence of humidity in the gas mixture. FTIR data before SO2 adsorption and after adsorption and regeneration did not indicate any change in the materials. Nonetheless, the SO2 working capacity decreased in consecutive adsorption/regeneration cycles due to evaporation of impregnated polyamines, rather than actual deactivation. FTIR and (13)C and (15)N CP-MAS NMR of fresh and SO2 adsorbed modified G3 on PME confirmed the formation of a complexation adduct.
含叔胺的聚（丙烯亚胺）第二代（G2）和第三代（G3）树枝状大分子以及聚乙烯亚胺（PEI）被开发用于选择性去除 SO2。通过傅里叶变换红外光谱（FTIR）和核磁共振（NMR）分析证实了伯胺和仲胺的 N-烷基化生成叔胺。这些改性聚胺被浸渍在两种纳米多孔载体上，即具有板状形态的 SBA-15PL 硅和乙醇提取的孔扩展 MCM-41（PME）复合材料。在 23°C 下存在 0.1%的 SO2/N2 时，负载在 SBA-15PL 上的改性 PEI、G2 和 G3 的吸附量分别为 2.07、2.35 和 1.71mmol/g，对应的 SO2/N 比分别为 0.22、0.4 和 0.3。在相同条件下，负载在 PME 上的改性 PEI 和 G3 的 SO2 吸附容量显著更高，达到 4.68 和 4.34mmol/g，对应的 SO2/N 比分别为 0.41 和 0.82。在升高的温度下，SO2 的工作吸附容量降低，这反映了该过程的放热性质。在气体混合物中存在湿度的情况下，这些材料的吸附容量显著增强。在吸附 SO2 之前和之后以及再生之后的 FTIR 数据并未表明材料发生任何变化。尽管如此，由于浸渍的聚胺蒸发，在连续的吸附/再生循环中，SO2 的工作容量会降低，而不是实际失活。负载在 PME 上的新鲜和吸附 SO2 的改性 G3 的 FTIR 和（13）C 和（15）N CP-MAS NMR 证实了络合加合物的形成。
